Metal casting and rolling line

Abstract

The invention relates to a metal casting and rolling line. A continuous casting and rolling line for casting, rolling and otherwise preparing metal strips can produce dispensable metal strips without the need for cold rolling or the use of a solution heat treatment line. The metal strip may be continuously cast by a continuous casting apparatus and wound into a metal roll, optionally after being subjected to post-casting quenching. The intermediate coil may be stored until ready for hot rolling. The as-cast metal strip may be reheated prior to hot rolling, during coil storage, or immediately prior to hot rolling. The heated metal strip may be cooled to a rolling temperature and hot rolled through one or more roll stands. The rolled metal strip may optionally be reheated and quenched prior to winding for transport. This final wound metal strip may have desired specifications and desired physical characteristics for distribution to manufacturing facilities.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a divisional application of the parent application No. 201780066754.9, the application date of which is September 27, 2017; the name of the invention is “Metal Casting and Rolling Line”.

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 413,591, entitled “DECOUPLED CONTINUOUS CASTING AND ROLLING LINE,” filed on October 27, 2016; U.S. Provisional Patent Application No. 62 / 505,944, entitled “DECOUPLED CONTINUOUS CASTING AND ROLLING LINE,” filed on May 14, 2017; U.S. Provisional Patent Application No. 62 / 413,764, entitled “HIGH STRENGTH 7XXX SERIES ALUMINUM ALLOYS AND METHODS OF MANUFACTURING THE SAME,” filed on October 27, 2016; U.S. Provisional Patent Application No. 62 / 413,740, entitled “HIGH STRENGTH 6XXX SERIES ALUMINUM ALLOYS AND METHODS OF MANUFACTURING THE SAME,” filed on October 27, 2016; and U.S. Provisional Patent Application No. 62 / 529,028, entitled “SYSTEM AND METHOD FOR MANUFACTURING ALUMINUM ALLOY PLATE,” filed on July 6, 2017, the disclosures of which are incorporated herein by reference in their entireties. Technical Field

[0004] The present disclosure relates to the production of metal billets, such as metal coils, and more particularly to the continuous casting and rolling of metals, such as aluminum. Background Art

[0005] Direct cooling (DC) and continuous casting are two methods of casting solid metal from liquid metal. In DC casting, liquid metal is poured into a mold with a retractable false bottom that can be withdrawn at the rate at which the liquid metal in the mold solidifies, typically producing a large and relatively thick ingot (e.g., 1500 mm×500 mm×5 m). The ingot can be processed, homogenized, hot rolled, cold rolled, annealed and / or heat treated, and otherwise finished before being coiled into a metal strip product that can be distributed to consumers of the metal strip product (e.g., automotive manufacturing facilities).

[0006] Continuous casting involves continuously injecting molten metal into a casting cavity defined between a pair of moving opposing casting surfaces and removing a cast metal form (e.g., metal strip) from an outlet of the casting cavity. Continuous casting is desirable where the entire product can be produced in a single fully coupled processing line. Such a fully coupled processing line involves matching or "coupling" the speed of the continuous casting equipment to the speed of the downstream processing equipment. Summary of the invention

[0007] Certain aspects and features of the present disclosure relate to decoupled and partially decoupled continuous casting and rolling lines for casting, rolling and otherwise preparing metal products (e.g., metal strips) suitable for providing dispensable metal strip coils. In some examples, metal products are prepared without the need for cold rolling or the use of a continuous annealing solution heat treatment (CASH) line. The metal strip can be continuously cast by a continuous casting device (such as a belt caster) and then optionally coiled into a metal coil after undergoing a post-casting quench. Such coiled cast metal strip can be stored until ready for hot rolling. The cast metal strip can be reheated before hot rolling (during coil storage or immediately before hot rolling). The heated metal strip can be cooled to rolling temperature and hot rolled through one or more rolling mill stands. The rolled metal strip can be optionally reheated and quenched before coiling for delivery. This final coiled metal strip can have the desired specifications and have the desired physical properties for distribution to manufacturing facilities.

[0008] Certain aspects and features of the present disclosure relate to casting an aluminum alloy with a high solidification rate, and thereafter subjecting the cast metal product to hot rolling or warm rolling to reduce the thickness of the metal product by at least about 30% or at or about 30%-80%, 40%-70%, 50%-70% or 60% to produce a hot zone. In some cases, the metal product may pass through an inline furnace before hot rolling or warm rolling, and the furnace may keep the metal product at a peak metal temperature of about 400°C-580°C for about 10-300 seconds, 60-180 seconds or 120 seconds. The hot zone product may be final size, final size and tempered, or may be ready for further processing, such as cold rolling and solution heat treatment. In some cases, an inline furnace may be particularly helpful for 5xxx series alloys to reduce thickness more during hot rolling or warm rolling. As used herein, the term thickness reduction may be in the form of cross-sectional reduction using rolling. Other types of cross-sectional reduction may include a reduction in the diameter of an extruded metal product. Hot rolling or warm rolling may be hot working or warm working, respectively. Other types of hot or warm processing may include hot extrusion or warm extrusion, respectively.

[0009] In some cases, the desired shape and size of the intermetallic particles can be achieved by continuous casting (e.g., at high solidification rates), optional heating in an inline furnace, and in-line hot or warm rolling at or about 50%-70% thickness reduction. These desired shapes and sizes of the intermetallic particles can facilitate further processing, such as cold rolling, and customer uses, such as bending and forming.

[0010] As used herein, temperature may appropriately refer to peak metal temperature. Likewise, references to duration at a particular temperature may refer to the duration starting when the metal article reaches the desired peak metal temperature (eg, excluding ramp-up time), although this is not always the case.

[0011] Aspects and features of the present disclosure can be used with any suitable metal, but may be particularly useful when casting and rolling aluminum alloys. Specifically, when casting alloys such as 2xxx series, 3xxx series, 4xxx series, 5xxx series, 6xxx series, 7xxx series or 8xxx series aluminum alloys, desired results can be achieved. For example, certain aspects and features of the present disclosure allow casting of 5xxx and 6xxx series alloys without the need for continuous annealing solution heat treatment. In another example, certain aspects and features of the present disclosure allow more effective and more reliable casting of 7xxx series alloys compared to current casting methods. In this specification, reference is made to alloys identified by aluminum industry names, such as "series" or "AA6xxx" or "6xxx". To understand the numerical designation system most commonly used to name and identify aluminum and its alloys, see "International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys" or "Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot," both published by The Aluminum Association.

[0012] In some cases, certain aspects and features of the present disclosure may be applicable to aluminum, aluminum alloys, titanium, titanium-based materials, steel, steel-based materials, magnesium, magnesium-based materials, copper, copper-based materials, composite materials, sheets used in composite materials, or any other suitable metal, non-metal, or combination of materials. In certain instances where the material being cast includes a metal, the metal may be a ferrous metal or a nonferrous metal.

[0013] Traditionally, the metal strip produced by a continuous casting unit is fed directly into a hot rolling mill for reduction to the desired thickness. Unlike DC casting, the clear benefits of continuous casting have traditionally relied on being able to feed the as-cast metal strip directly into the production line. Because the continuously cast product is fed directly into the rolling mill, casting speeds and rolling speeds must be carefully matched to avoid inducing undesirable tensions in the metal strip, which could result in unusable product, equipment damage, or hazardous conditions.

[0014] Surprisingly, by intentionally decoupling the casting process from the hot rolling process in a continuous casting and rolling system, beneficial results can be achieved. By decoupling the continuous casting process from the hot rolling process, the casting speed and the rolling speed no longer need to be closely matched. Instead, the casting speed can be selected to produce the desired properties in the metal strip, and the rolling speed can be selected based on the requirements and limitations of the rolling equipment. In a decoupled continuous casting and rolling system, the continuous casting device can cast a metal strip that is immediately or soon after being coiled into an intermediate or transfer coil. The intermediate coil can be stored or immediately introduced into the rolling equipment. In the rolling equipment, the intermediate coil can be unfolded, allowing the metal strip to pass through the rolling equipment for hot rolling and other processing. The final result of the hot rolling process is a metal strip that may have the characteristics required by a specific customer. The metal strip can be coiled and distributed, for example, to an automotive factory that can form automotive parts from the metal strip. In some cases, the metal strip can be heated at various points after initially casting (e.g., by a continuous caster) in a continuous casting process, but the metal strip will remain below the solidus temperature of the metal strip.

[0015] As used herein, the term decoupling refers to the removal of the speed connection between the casting device and the rolling stand. As described above, a coupled system (sometimes referred to herein as an in-line system) will include a continuous casting device that feeds directly into the rolling stand, such that the output speed of the casting device must match the input speed of the rolling stand. In an uncoupled system, the casting speed can be set regardless of the input speed of the rolling stand, and the speed of the rolling stand can be set regardless of the output speed of the casting device. Various examples described herein decouple the casting device from the rolling stand by having the casting device output a metal coil at a first speed, and then subsequently feeding the coil into the rolling stand for rolling at a second speed. In some cases where a casting speed faster than the desired rolling speed can accommodate is required, it is possible to provide limited decoupling of the output speed of the casting device and the input speed of the rolling stand, even when the casting device feeds the cast metal strip directly to the rolling stand by using an accumulator located between the casting device and the rolling stand.

[0016] The casting apparatus may be any suitable continuous casting apparatus. However, surprisingly desirable results have been achieved using a belt casting apparatus, such as that described in U.S. Pat. No. 6,755,236, entitled "BELT-COOLING AND GUIDING MEANS FOR CONTINUOUS CASTING OF METAL STRIP," the disclosure of which is incorporated herein by reference in its entirety. In some cases, particularly desirable results may be achieved by using a belt casting apparatus having a belt made of a metal having a high thermal conductivity, such as copper. The belt casting apparatus may include a belt made of a metal having a thermal conductivity of at least 250, 300, 325, 350, 375, or 400 watts per meter per Kelvin at the casting temperature, although metals having other thermal conductivity values ​​may be used. The casting apparatus may cast metal strips of any suitable thickness, but desired results have been achieved at thicknesses of about 7 mm to 50 mm.

[0017] Certain aspects of the present disclosure can improve the formation and distribution of dispersions within the aluminum matrix. Dispersions are a collection of other solid phases located within the primary phase of a solidified aluminum alloy. Various factors during casting, processing, heating, and rolling can significantly affect the size and distribution of dispersions in the metal strip. It is known that dispersions contribute to the bending properties and other characteristics of aluminum alloys, and generally require a size between about 10 nm and about 500 nm and a relatively uniform distribution throughout the metal strip. In some cases, the desired dispersion can be a size of about 10 nm to 100 nm or 10 nm to 500 nm. In DC casting, a long homogenization cycle (e.g., 15 hours or longer) is required to produce the desired dispersion distribution. In standard continuous casting, dispersions are generally not present at all or are present in small amounts, which cannot provide any beneficial effects.

[0018] Certain aspects of the present disclosure relate to metal strips and systems and methods for forming metal strips having desired dispersions (e.g., desired distributions of dispersions of desired sizes). In some cases, the casting apparatus can be configured to provide rapid solidification (e.g., rapid solidification at a rate at or greater than about 10 times faster than standard DC casting solidification, such as at least at or about 1°C / s, at least at or about 10°C / s, or at least at or about 100°C / s) and rapid cooling (e.g., rapid cooling at a rate at or about 1°C / s, at least at or about 10°C / s, or at least at or about 100°C / s) of the metal strip, which can promote improvements in the microstructure in the final metal strip. In some cases, the solidification rate can be 100 times or more than the solidification rate of conventional DC casting. Rapid solidification can produce a unique microstructure, including a unique distribution of dispersion-forming elements that are extremely uniformly distributed throughout the solidified aluminum matrix. Rapid cooling of the metal strip, such as quenching the metal strip immediately upon exiting the casting apparatus, or shortly thereafter, can help lock the dispersion-forming elements into solid solution. The resulting metal strip can then be supersaturated with the dispersion forming elements. The supersaturated metal strip can then be wound into an intermediate coil for further processing in a decoupled casting and rolling system. In some cases, the desired dispersion forming elements include manganese, chromium, vanadium and / or zirconium. When reheated, this metal strip supersaturated with the dispersion forming elements can very quickly induce precipitation of a uniformly distributed and ideally sized dispersion.

[0019] In some cases, rapid solidification and rapid cooling can be performed separately by a casting device. The casting device may have sufficient length and have sufficient heat removal characteristics to produce a metal strip supersaturated with dispersion forming elements. In some cases, the casting device may have sufficient length and have sufficient heat removal characteristics to reduce the temperature of the cast metal strip to be at or below 250°C, 240°C, 230°C, 220°C, 210°C or 200°C, but other values ​​may also be used. Typically, such a casting device will have to occupy a significant space or operate at a slow casting speed. In certain cases where a smaller and faster casting device is required, the metal strip may be quenched immediately after leaving the casting device or quenched shortly thereafter. One or more nozzles may be located downstream of the casting device to reduce the temperature of the metal strip to be at or below 250°C, 240°C, 230°C, 220°C, 210°C, 200°C, 175°C, 150°C, 125°C or 100°C, but other values ​​may also be used. The quenching may occur sufficiently or rapidly to lock the dispersion forming elements into the supersaturated metal strips.

[0020] Traditionally, rapid solidification and rapid cooling have been avoided because the resulting metal strip has undesirable properties. However, it has been unexpectedly discovered that a metal strip supersaturated with a dispersion forming element can be an effective precursor to a metal strip having a desired dispersion arrangement. The unique, dispersion forming element supersaturated metal strip can be reheated, for example during storage or immediately prior to hot rolling, to convert the matrix supersaturated with the dispersion forming element into a strip containing a desired distribution (e.g., a uniform distribution) and a desired size (e.g., between about 10 nm and about 500 nm or between about 10 nm and about 100 nm) of dispersion. Because the metal strip is supersaturated with the dispersion forming element, the precipitation driving force for the dispersion of the desired size is higher than for a non-supersaturated matrix. In other words, certain rapid solidification and / or cooling aspects as disclosed herein can be used to prepare or fill a metal strip, which can then be briefly reheated to produce a desired dispersion arrangement. For example, it has been found that certain aspects of the present disclosure are capable of producing metal strips that are supersaturated with dispersion forming elements and that can be reheated to precipitate a dispersion of a desired size at a reheating time that is 10-100 times shorter than that of the prior art (e.g., DC casting). In addition, the speed at which such reheating can be performed enables reheating to be performed in a hot rolling line, such as at the beginning of a hot rolling line. However, in some cases, one or more metal strip coils that are supersaturated in the dispersion forming elements can be reheated before being unrolled on the hot rolling line. Because the dispersion of the desired size can be drawn out more quickly, a significant amount of time and energy can be saved in producing the desired metal strip. In addition, the improved dispersion distribution can achieve the desired properties by using a smaller amount of alloying elements. In other words, certain aspects and features of the present disclosure enable alloying elements to be utilized more efficiently than conventional DC or continuous casting.

[0021] In addition, the manipulation of one or more of the solidification rate, cooling (e.g., quenching) rate, and reheating time can be used to specifically customize the dispersion size and distribution as needed. A controller can be coupled to the system to control the solidification rate, cooling rate, and reheating time. When it is desired that the metal strip has a certain characteristic attributable to a specific dispersion arrangement (e.g., size and / or distribution), the controller can manipulate various rates / times to produce the desired metal strip. In this way, a metal strip with a desired dispersion arrangement can be produced as needed. Because controlling the dispersion arrangement can provide more or less efficiency in how to utilize alloying elements, the on-demand control of the dispersion arrangement can enable the controller to compensate for the deviation of the alloying elements of a specific liquid metal mixture. For example, when producing a conveyable metal strip with certain desired characteristics, the controller can compensate for slight deviations in the concentration of alloying elements between castings by adjusting the solidification rate, cooling rate, and / or reheating time of the system to produce a dispersion arrangement that provides a more efficient or less efficient use of alloying elements (e.g., when determining a negative deviation of an alloying element, a more efficient use may be required). This compensation can be performed automatically, or can be automatically recommended to the user.

[0022] Intermediate coils can be stored prior to hot rolling, thus allowing the casting plant to output at a faster rate than the hot rolling stands can accommodate, with excess metal strip being coiled and stored until the hot rolling stands are available. While stored, the intermediate coils can optionally be reheated. For example, for various types of aluminum alloys, the intermediate strip can be reheated to a temperature at or about 500°C or higher, or at or about 530°C and higher. The reheating temperature will remain below the solidus temperature of the metal strip.

[0023] In some cases, the intermediate coil is maintained at a temperature of about or above 100°C, at or above 200°C, at or above 300°C, or at or above 400°C, or at or above 500°C, although other values ​​may be used. In some cases, the intermediate coil can be stored in a manner that minimizes uneven radial forces that may hinder unwinding during hot rolling. In some cases, the intermediate coil can be stored vertically so that the transverse axis of the coil extends in the vertical direction. In some cases, the intermediate coil can be stored horizontally so that the transverse axis of the coil extends in the horizontal direction. In some cases, the intermediate coil can be suspended on a central shaft to minimize the weight of the coil's rings compressing each other, particularly the portion of the coil located below the shaft. In some cases, the intermediate coil can be rotated periodically or continuously around a horizontal axis (e.g., the transverse axis of the coil when stored horizontally).

[0024] During the hot rolling process, the intermediate coil may be unrolled, optionally surface treated, optionally reheated, rolled to a desired thickness, optionally reheated and quenched after rolling, and coiled for distribution. The hot rolling process may include one or more hot rolling stands, each hot rolling stand including work rolls for applying forces to reduce the thickness of the metal strip. In some cases, the total amount of thickness reduction during the hot rolling process may be or less than about 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, or 15%, although other values ​​may be used. Hot rolling may be performed at relatively high speeds, such as an entry speed (e.g., the speed of the metal strip when entering the first hot rolling stand) of about 50 to about 60 meters per minute (m / min), although other entry speeds may be used. The exit speed (e.g., the speed of the metal strip when it leaves the last hot rolling stand) can be much faster due to the percentage of thickness reduction applied by the hot rolling stand, such as about 300 to about 800 m / min, although other exit speeds may occur. To obtain the desired results, hot rolling can be carried out at a hot rolling temperature. The hot rolling temperature can be at or about 350°C, such as between 340°C and 360°C, 330°C and 370°C, 330°C and 380°C, 300°C and 400°C, or between 250°C and 400°C, although other ranges can also be used. In some cases, the desired hot rolling temperature of the metal strip can be its alloy recrystallization temperature. In some cases, the temperature of the metal strip can move from the starting hot rolling temperature (e.g., the temperature of the metal strip when it enters the first hot rolling stand), optionally through one or more inter-stand hot rolling temperatures (e.g., the temperature of the metal strip between any two adjacent hot rolling stands), to the exit hot rolling temperature (e.g., the temperature when the metal strip leaves the last hot rolling stand). Any of these temperatures may be within the range of hot rolling temperatures described above, but other ranges may also be used. The starting hot rolling temperature, optional inter-stand temperature, and exit hot rolling temperature may be approximately the same (see, e.g., Figure 7 ) or may be different (see, for example, Figure 8 ).

[0025] In some cases, the metal strip may enter the hot rolling process at an elevated temperature, or, as disclosed above, may be reheated shortly after being unrolled into the hot rolling system. The temperature of the metal strip at this point may be in excess of 500°C, 510°C, 520°C, or 530°C, but below the melting point, although other ranges may also be used. The metal strip may be cooled to the hot rolling temperature described above before entering the hot rolling stand. After passing through the hot rolling stand, the metal strip may optionally be heated to a post-rolling temperature. For heat-treatable alloys, such as 6xxx series and 7xxx series aluminum alloys, the post-rolling temperature may be at or near the solution temperature, while for non-heat-treatable alloys, such as 5xxx series aluminum alloys, the post-rolling temperature may be the recrystallization temperature. In some cases, such as for non-heat-treatable alloys, post-rolling heating may not be used, particularly if the metal strip exits the hot rolling process at a temperature at or above the recrystallization temperature (e.g., at or above about 350°C). For heat treatable alloys, the post-rolling temperature or solution temperature may vary depending on the alloy, but may be at or above about 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, and 530°C. In some cases, the solution temperature may be just or about 20°C-40°C, or more preferably 30°C, lower than the solidus temperature of the alloy in question. Immediately after or shortly after the metal strip is reheated to the post-rolling temperature, the metal strip may be quenched. The metal strip may be quenched to a coiling temperature, which may be at or below 150°C, 140°C, 130°C, 120°C, 110°C, or 100°C, although other values ​​may also be used. The metal strip may then be coiled for delivery. At this point, the coiled metal strip may have the desired physical properties for distribution, such as the desired gauge and the desired temper.

[0026] After hot rolling and quenching, the metal strip may have a desired gauge and temper, such as a T4 temper. Reference is made to alloy tempers or conditions in this application. For the most commonly used alloy temper descriptions, see "American National Standard (ANSI) H35 for Alloy and Temper Designation System". The F condition or temper state refers to the aluminum alloy as manufactured. The O condition or temper state refers to the aluminum alloy after annealing. The W condition or temper state refers to the aluminum alloy after solution heat treatment, although it may be an unstable temper state at ambient temperature. The T condition or temper state refers to the aluminum alloy that has undergone a certain heat treatment to produce a stable temper state. The T3 condition or temper state refers to the aluminum alloy after solution heat treatment (i.e., solid solution), cold working and natural aging. The T4 condition or temper state refers to the aluminum alloy after solution heat treatment (i.e., solid solution) followed by natural aging. The T6 condition or temper state refers to the aluminum alloy after solution heat treatment followed by artificial aging. The T8 condition or temper state refers to the aluminum alloy after cold working, followed by solution heat treatment, and then artificial aging.

[0027] In some cases, a metal strip (e.g., an aluminum metal strip) can be dynamically recrystallized during hot rolling by starting hot rolling at a high temperature (e.g., a hot rolling inlet temperature above the recrystallization temperature, such as at or above about 550° C.) and cooling the metal strip to a hot rolling outlet temperature during hot rolling. In some cases, dynamic recrystallization during hot rolling or warm rolling can occur by applying sufficient force to induce sufficient strain on the metal article during rolling at a specific temperature to cause the metal article to recrystallize.

[0028] Dynamic recrystallization allows the metal strip to be quenched immediately after hot rolling without the need to reheat the metal strip (e.g., to a temperature above the recrystallization temperature) to achieve recrystallization. In addition, by rapidly quenching immediately after hot rolling, undesirable precipitation can be avoided. At certain temperatures, precipitates (such as Mg2Si phases) may begin to form over time. A high precipitation zone can be defined based on the temperature and time spent at the temperature, where precipitates are expected to form quickly, such as 1% to 90% precipitation completion. Therefore, in order to minimize precipitate formation, it may be necessary to minimize the time spent in the high precipitation zone. By dynamic recrystallization followed by rapid quenching, the amount of time the metal strip spends at temperatures within the high precipitation zone can be minimized. In some cases, desired metallurgical properties can be achieved by hot rolling and quenching the metal strip, wherein the metal strip monotonically decreases in temperature from just before entering the first hot rolling stand to just after leaving the quenching zone (e.g., the temperature decreases monotonically throughout the hot rolling and quenching process).

[0029] In some cases, after little or no initial quenching, the metal strip may enter hot rolling. During hot rolling, the metal strip may be dropped from a hot rolling inlet temperature above the recrystallization temperature (e.g., a preheat temperature, e.g., at or above 550° C.) to a hot rolling outlet temperature below the hot rolling inlet temperature. The temperature drop from the hot rolling inlet temperature to the hot rolling outlet temperature may be a monotonic drop. In order to achieve a temperature drop during hot rolling, each stand of the hot rolling mill may extract heat from the metal strip. For example, the hot rolling stands may be sufficiently cooled so that passing the metal strip through the hot rolling stands may extract heat from the metal strip through the working rolls of the hot rolling stands. In some cases, heat may be extracted from the metal strip between the hot rolling stands by using a lubricant or other cooling material (e.g., a fluid such as air or water), instead of or in addition to removing heat through the hot rolling stands themselves. In some cases, the last and second to last hot rolling stands may roll the metal strip at a gradually decreasing temperature. In some cases, the last and second to last hot rolling stands may roll the metal strip at the same or substantially the same temperature.

[0030] Rather than relying on post-rolling (e.g., after hot rolling) recrystallization during the heat treatment process, which may require elevated temperatures prior to quenching and may result in an extended duration in the high precipitation zone, the metal strip may undergo dynamic recrystallization during hot rolling, as described herein. Dynamic recrystallization may include rolling the metal strip at a sufficiently high strain rate and a sufficiently high temperature. Dynamic recrystallization may be performed in the final rolling stand of a hot rolling mill. Dynamic recrystallization depends on the strain rate and temperature of the metal strip being processed. The Zener-Hollomon parameter (Z) may be expressed by the formula Definition, where is the strain rate, Q is the activation energy, R is the gas constant, and T is the temperature. Recrystallization occurs when the Zener-Holomon parameters fall within the desired range. In order to remain within this range while minimizing the temperature (e.g., the hot rolling exit temperature), the metal strip must be subjected to a higher strain rate than would be required at a higher temperature. Therefore, it may be necessary to maximize the reduction (e.g., percentage thickness reduction) of the final hot rolling stand or at least select a reduction suitable for achieving a hot rolling exit temperature suitable for rapid quenching to minimize the time spent in the high precipitation zone. In order to achieve the desired total thickness reduction, the thickness reduction added to the final hot rolling stand can be offset by reducing the thickness reduction provided by one or more of the preceding hot rolling stands.

[0031] In addition, in order to minimize the time spent in the high precipitation zone, it may be necessary to run the hot rolling mill at a high speed. For example, in a hot rolling mill using three stands to reduce the metal strip from a gauge of 16 mm to 2 mm, a strip speed of approximately 50 m / min at the hot rolling mill entrance may result in a strip speed of approximately 400 m / min at the hot rolling mill exit. Therefore, in order to achieve a suitable minimum duration in the high precipitation zone, the quenching process may require reducing the temperature of the metal strip by approximately 400 ° C (e.g., to 100 ° C) while the metal strip is advancing at a speed of approximately 400 m / min. In some metals (such as steel), such rapid quenching is impossible, may be impractical, or may require large, expensive and inefficient equipment. In aluminum, it is possible to provide such quenching as described herein, especially if the recrystallization temperature is minimized by moving a portion of the thickness reduction from an earlier hot rolling stand to the final hot rolling stand. In addition, when the hot rolling process is decoupled from the casting process, the hot rolling process can be allowed to proceed at a high speed (such as those described herein). High speeds during hot rolling help minimize the time spent in the high precipitation zone. Additionally, as described herein, high hot rolling speeds can help achieve the appropriately high strain rates required to achieve low recrystallization temperatures.

[0032] In addition, by using relatively thin metal strips, dynamic recrystallization and rapid quenching can be promoted to minimize precipitate formation. By casting the metal strip with a relatively thin gauge as described herein, the hot rolling process can be carried out at a high speed and can be followed by a rapid quenching process, which can reduce the time spent in high precipitation areas. Thin gauges can also promote high hot rolling speeds. The techniques described herein for dynamic recrystallization and rapid quenching can help prepare metal strips or other metallurgical products with a T4 temper and having less than the expected amount of precipitates. For example, a metal strip prepared according to certain aspects of the present disclosure may have a T4 temper and have a volume fraction of Mg2Si at or less than approximately 4.0%, 3.9%, 3.8%, 3.7%, 3.6%, 3.5%, 3.4%, 3.3%, 3.2%, 3.1%, 3.0%, 2.9%, 2.8%, 2.7%, 2.6%, 2.5%, 2.4%, 2.3%, 2.2%, 2.1%, 2.0%, 1.9%, 1.8%, 1.7%, 1.6%, 1.5%, 1.4%, 1.3%, 1.2%, 1.1%, 1.0%, 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, or 0.1%. In some cases, metal strips prepared according to certain aspects of the present disclosure may have a T4 temper and have a relative humidity at or less than approximately 10%, 9.9%, 9.8%, 9.7%, 9.6%, 9.5%, 9.4%, 9.3%, 9.2%, 9.1%, 9%, 8.9%, 8.8%, 8.7%, 8.6%, 8.5%, 8.4%, 8.3%, 8.2%, 8.1%, 8%, 7.9%, 7.8%, 7.7%, 7.6%, 7.5%, 7.4%, 7.6%, 7.7%, 7.8%, 7.9%, 7.9%, 7.8 ... %, 7.3%, 7.2%, 7.1%, 7%, 6.9%, 6.8%, 6.7%, 6.6%, 6.5%, 6.4%, 6.3%, 6.2%, 6.1%, 6%, 5.9%, 5.8%, 5.7%, 5.6%, 5.5%, 5.4%, 5.3%, 5.2%, 5.1%, 5%, 4.9%, 4.8%, 4.7%, 4.6%, 4.5%, 4.4%, 4.3%, 4.2% or 4.1% Mg2Si volume fraction. As used herein, reference to the volume fraction of Mg2Si may refer to the volume fraction of Mg2Si relative to the total amount of Mg2Si that may be formed in the particular alloy being cast. The percentage of the volume fraction of Mg2Si may also be referred to as the completion percentage of the precipitation reaction to form Mg2Si.

[0033] Certain aspects and features of the present disclosure relate to techniques for adjusting the size, shape, and size distribution of iron-containing (Fe-containing) intermetallic compounds. Adjusting the properties of iron-containing intermetallic compounds may be very important for achieving optimal product performance, particularly for 6xxx series alloys, and especially for the demanding specifications required for aluminum automotive parts. Although conventional DC casting may require high temperature (e.g., >530°C) homogenization for a long time (e.g., several hours) to convert β-phase Fe (β-Fe) into α-phase Fe (α-Fe) intermetallic compounds, certain aspects of the present disclosure are applicable to the production of metal products with desired Fe-containing intermetallic compounds. As described herein, certain aspects of the present disclosure relate to the production of intermediate specification products by a continuous caster. Intermediate specification products can be processed into T4 tempered products by i) cold rolling to final specifications and solution heat treatment; ii) warm rolling to final specifications and solution heat treatment; iii) hot rolling to final specifications, reheating with magnetic heaters, and online quenching; iv) hot rolling to final specifications and solution heat treatment; or v) hot rolling to final specifications by dynamic recrystallization to produce T4 tempered conditions.

[0034] In some cases, the metal strip cast by the continuous caster may be rolled (e.g., hot rolled) prior to coiling. The rolling prior to coiling may be a substantial reduction in thickness, such as at least 30% or more typically between 50% and 75%. Particularly useful results have been found when the continuously cast metal strip is rolled with a single hot rolling stand prior to coiling, although additional stands may be used in some cases. In some cases, such a substantial reduction (e.g., a thickness reduction of greater than 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%) hot rolling after continuous casting may help break up Fe-containing particles in the metal strip, among other benefits. If the thickness of the metal strip is reduced by rolling after continuous casting and prior to coiling, any hot rolling process that occurs after unwinding may require one less hot rolling stand and / or one less pass, since the metal strip has already reduced in thickness between casting and coiling.

[0035] In some cases, the metal strip can be flash homogenized. Flash homogenization can include heating the metal strip to a temperature above 500°C (e.g., 500-570°C, 520-560°C, or at or about 560°C) for a relatively short period of time (e.g., about 1 minute to 10 minutes, such as 30 seconds, 45 seconds, 1 minute, 1:30 minutes, 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, or 10 minutes, or any range therebetween). Such heating can occur between the continuous caster and the initial coiling, and more specifically, between the continuous caster and the hot rolling stand before coiling, or between the hot rolling stand and the coiling. Such flash homogenization can help reduce the aspect ratio of the Fe-containing intermetallic compounds (e.g., alpha or beta type), and can also reduce the size of these intermetallic compounds. In some cases, flash homogenization (eg, at 570°C for about 2 minutes) can successfully achieve beneficial spheroidization and / or refinement of the Fe component particles that would otherwise require extensive homogenization at higher temperatures.

[0036] In some cases, as described herein, a combination of flash homogenization and substantially reduced hot rolling following continuous casting may be particularly useful for refining (eg, breaking up) Fe-containing particles.

[0037] In one example, the casting system may include a continuous caster, a furnace (e.g., a tunnel furnace), a hot rolling stand, and a coiler. In some cases, one or more quenchings may occur before and / or after the hot rolling stand. The hot rolling stand may reduce the thickness of the metal strip by at least 30% or 50-70%. The quenching before the hot rolling stand may be optional, but it may advantageously break up the Fe-containing particles and improve the precipitation characteristics. In some cases, after hot rolling, quenching, and coiling, the metal strip may be hot rolled after slow / fast heating and soaking at a relatively high temperature (e.g., >500°C). In some cases, after hot rolling, quenching, and coiling, the metal strip may be warm rolled after slow / fast heating to a relatively low temperature (e.g., <350°C). In some cases, after hot rolling, quenching, and coiling, the metal strip may be cold rolled without any further heat treatment. As described herein, these various techniques may produce various characteristics regarding Fe-containing particles, such as various Fe component size distributions.

[0038] In some cases, the metal strip can be reheated at various points in the hot rolling system by using a heating device, such as a magnetic heater, such as an induction heater or a rotating magnet heater. Non-limiting examples of suitable rotating magnet heaters include those disclosed in U.S. Provisional Application No. 62 / 400,426, entitled “ROTATING MAGNET HEAT INDUCTION”, filed on September 27, 2016, the disclosure of which is incorporated herein in its entirety.

[0039] Typically, the rolling stands of a hot rolling system are cooled, for example, by a coolant system including nozzles that spray coolant onto the rolls of the rolling stand and / or onto the metal strip itself. This coolant system can extract sufficient heat so that the mechanical action of reducing the thickness of the metal strip by passing the metal strip through the hot rolling stand does not increase the temperature of the metal strip. However, in certain circumstances, the metal strip can be intentionally reheated by reducing the amount of cooling applied by the coolant system, thereby allowing the mechanical action of reducing the thickness of the metal strip by passing the metal strip through the hot rolling stand to impart a positive temperature change in the metal strip.

[0040] As used herein, various cooling and / or quenching devices are described with reference to a coolant supplied by one or more nozzles. Other mechanisms may be used to rapidly cool the metal strip, whether fluid-based or not, and whether nozzle-based or not. In some cases, the metal strip may be cooled or quenched using a large amount of coolant, such as provided directly from a hose, conduit, tank, or other such structure for delivering the coolant to the metal strip.

[0041] Aspects and features of the present disclosure are described herein with respect to producing metal strip, however, aspects of the present disclosure may also be used to produce metal products of any suitable size or form, such as foil, sheet, slab, plate, plate, or other metal product.

[0042] These illustrative examples are given to introduce the reader to the general subject matter discussed herein and are not intended to limit the scope of the disclosed concepts. The following section describes various additional features and examples with reference to the accompanying drawings, wherein like numbers represent like elements, and directional descriptions are used to describe the illustrative embodiments, but similar to the illustrative embodiments, and are not intended to limit the present disclosure. Elements included in the description herein may not be drawn to scale.

[0043] Figure 1is a schematic diagram depicting a decoupled metal casting and rolling system 100 according to certain aspects of the present disclosure. The decoupled metal casting and rolling system 100 may include a casting system 102, a storage system 104, and a hot rolling system 106. The decoupled metal casting and rolling system 100 may be viewed as a single continuous processing line with decoupled subsystems. A metal bar 110 cast by the casting system 102 may continue in a downstream direction through the storage system 104 and the hot rolling system 106. The decoupled metal casting and rolling system 100 may be viewed as continuous because the metal bar 110 may be continuously produced by the casting system 102, stored by the storage system 104, and hot rolled by the hot rolling system 106. In some cases, the decoupled metal casting and rolling system 100 may be located within a single building or facility, but in some cases, the subsystems of the decoupled metal casting and rolling system 100 may be located separately from each other. In some cases, a single casting system 102 may be associated with one or more storage systems 104 and one or more hot rolling systems 106, thereby allowing the casting system 102 to operate continuously at a much higher rate than a single storage system 104 or hot rolling system 106 would otherwise permit.

[0044] The casting system 102 includes a continuous casting device, such as a belt caster 108, which continuously casts a metal strip 110. The casting system 102 may optionally include a rapid quenching system 114 located immediately downstream or shortly after the belt caster 108. The casting system 102 may include a coiling device capable of coiling the metal strip 110 into an intermediate coil 112.

[0045] The intermediate coil 112 accumulates a portion of the metal strip 110 leaving the belt caster 108 and, after being cut by a shear or other suitable device, can be transported to another location, thereby allowing a new intermediate coil 112 to be formed thereafter from other metal strips 110 leaving the belt caster 108, thereby allowing the belt caster 108 to operate continuously or semi-continuously.

[0046] The intermediate coil 112 may be provided directly to the hot rolling system 106, or may be stored and / or processed in the storage system 104. The storage system 104 may include various storage mechanisms, such as vertical or horizontal storage mechanisms and periodic or continuously rotating storage mechanisms. In some cases, when the intermediate coil 112 is stored in the storage system 104, it may be preheated in a preheater 116 (e.g., a furnace). When the intermediate coil 112 is in the storage system 104, preheating may occur for some or all of the duration. After being stored in the storage system 104, the metal strip 110 may be provided to the hot rolling system 106.

[0047] The hot rolling system 106 can reduce the thickness of the metal strip 110 from the as-cast gauge to the gauge required for the distribution. In some cases, the gauge required for the distribution can be at or about 0.7 mm to 4.5 mm, or at or about 1.5 mm to 3.5 mm. The hot rolling system 106 can include a group of hot rolling stands 118 for reducing the thickness of the metal strip 110. In some cases, the group of hot rolling stands 118 can include a single hot rolling stand, but any number of hot rolling stands can be used, such as two, three, or more. In some cases, using a greater number of hot rolling stands (e.g., three, four, or more) can produce better surface quality for a given total thickness reduction (e.g., thickness reduction before the first hot rolling stand to after the last hot rolling stand) because each rolling stand is therefore required to reduce the thickness of the metal by a smaller amount, and therefore generally imposes fewer surface defects on the metal strip. The hot rolling system 106 can further perform other processing of the metal strip, such as surface finishing (e.g., texturing), preheating, and heat treatment. The metal strip 110 exiting the hot rolling system 106 may be provided directly to additional processing equipment (e.g., a punch or bender), or may be wound into a dispensable coil 120 (e.g., a finished coil). As used herein, the term "dispensable" may describe a metal product, such as a coiled metal strip, that has the desired metal strip properties for a consumer. For example, the dispensable coil 120 may include a coiled metal strip having physical and / or chemical properties that meet the specifications of an original equipment manufacturer. The dispensable coil 120 may be in a W temper or a T temper. The dispensable coil 120 may be stored, sold, and shipped as appropriate.

[0048] Figure 1 The decoupled metal casting and rolling system 100 depicted in FIG. 1 allows the speed of the casting system 102 to be decoupled from the speed of the hot rolling system 106. As depicted, the decoupled metal casting and rolling system 100 uses a storage system 104 to store intermediate coils 112, wherein the metal strip 110 leaving the belt caster 108 is coiled into discrete units and stored until the hot rolling system 106 is available for processing. In some cases, the storage system 104 uses an inline accumulator instead of storing the intermediate coil 112, and the inline accumulator receives the metal strip 110 from the casting system 102 at a first speed and accumulates it between a set of moving rollers to allow the continuous metal strip 110 to be fed into the hot rolling system 106 at a second speed different from the first speed. Based on the desired casting duration of the casting system 102, the inline accumulator can be sized to accommodate the difference in the first speed and the second speed for a predetermined period of time. In systems where it is desired that the casting system 102 operate continuously, a coil-based storage system 104 may be required.

[0049] Figure 22 is a timing diagram 200 for producing various coils using a decoupled metal casting and rolling system according to certain aspects of the present disclosure. The timing diagram 200 depicts the position of each coil over time and the processes performed on it as the coils pass from a casting system 202 through a storage system 204 and through a hot rolling system 206. The casting system 202, the storage system 204, and the hot rolling system 206 may be Figure 1 The decoupled metal casting and rolling system 100 includes a casting system 102 , a storage system 104 , and a hot rolling system 106 .

[0050] As described above, the casting system 202 can cast intermediate coils. Boxes 222A, 222B, 222C, 222D, and 222E represent the casting times of intermediate coils A, B, C, D, and E, respectively. The casting system 202 can cast each intermediate coil at a specific casting speed. Therefore, the coil casting time 228 can represent the time required for the casting system 202 to cast and wind a single intermediate coil. In some cases, the casting system 202 experiences a reset time during which the casting system 202 is reset to cast and wind a subsequent intermediate coil. In other cases, the casting system 202 can immediately begin casting and winding a subsequent intermediate coil. As shown in FIG. Figure 2 As depicted, the casting system 202 can continuously and repeatedly output the intermediate coil.

[0051] The intermediate coils may be transferred to the storage system 204 for storage and / or optional processing (e.g., reheating). Boxes 224A, 224B, 224C, 224D, and 224E represent storage durations for the intermediate coils A, B, C, D, and E, respectively. Since the speed of the casting system 202 is decoupled from the speed of the hot rolling system 206, the storage system 204 may be able to store any suitable number of intermediate coils for varying amounts of time, depending on the number of hot rolling systems 206 available and the speeds of the casting system 202 and the hot rolling system 206.

[0052] In some cases, each intermediate coil may remain in storage system 204 for a minimum storage time 230, which may be the minimum amount of time required to perform any optional processing during storage. In some cases, there is no minimum storage time 230, and if hot rolling system 206 is available to receive the intermediate coils, the intermediate coils may be delivered to hot rolling system 206 without being stored. For example, if there is no minimum storage time 230, intermediate coil A will be delivered directly to hot rolling system 206, and block 224A will not exist.

[0053] Intermediate coils provided to the hot rolling system 206 may be rolled and otherwise processed into dispensable coils. Boxes 226A, 226B, 226C, 226D, and 226E represent the duration that intermediate coils A, B, C, D, and E, respectively, spend in the hot rolling system 206. The hot rolling system 206 may be operated at a set speed, resulting in a coil rolling time 232, which represents the duration required to hot roll and otherwise process the intermediate rolls in the hot rolling system 206.

[0054] As can be appreciated, when decoupled, the process of casting, storing, and hot rolling the metal strip is continuous as the metal strip is continuously transferred from one system to the next. The storage system 204 may be particularly desirable when the coil casting time 228 is shorter than the coil rolling time 232. The difference between the coil casting time 228 and the coil rolling time 232 may indicate the required size of the storage system 204 as a function of the total casting duration (e.g., the total length of time required for the casting system 202 to continuously cast the intermediate coil before shutting down).

[0055] Figure 3 300 is a schematic diagram depicting a decoupled continuous casting system 300 according to certain aspects of the present disclosure. The decoupled continuous casting system 300 includes a continuous casting device, such as a belt caster 308. The belt caster 308 includes a relative belt 334 capable of extracting heat from liquid metal 336 at a cooling rate sufficient to solidify the liquid metal 336, which is discharged from the belt caster 308 as a metal strip 310 once solidified. The belt caster 308 can be operated at a desired casting speed. The relative belt 334 can be made of any suitable material, however, in some cases, the belt 334 is made of copper. The cooling system within the belt caster 308 can extract enough heat from the liquid metal 336 so that the metal strip 310 leaving the belt caster 308 has a temperature between 200°C and 530°C, but other ranges can also be used.

[0056] In some cases, rapid solidification and rapid cooling can be achieved by using a belt caster 308 that is configured to extract enough heat from the metal so that the metal strip 310 exiting the belt caster 308 has a temperature of less than 200° C. In other cases, rapid post-casting cooling can be performed by a quench system 314 located immediately downstream or shortly after the belt caster 308. The quench system 314 can extract enough heat from the metal strip 310 so that the metal strip exits the quench system 314 at a temperature of 100° C. or less, regardless of the temperature of the metal strip 310 exiting the belt caster 308. As an example, the quench system 314 can be configured to reduce the temperature of the metal strip 310 to 100° C. or less in approximately ten seconds.

[0057] The quench system 314 may include one or more nozzles 340 for distributing a coolant 342 onto the metal strip 310. The coolant 342 may be fed to the nozzle 340 from a coolant source 346 coupled to the nozzle 340 via an appropriate conduit. The quench system 314 may include one or more valves 344, including valves 344 associated with the one or more nozzles 340 and / or valves 344 associated with the coolant source 346, to adjust the amount of coolant 342 applied to the metal strip 310. In some cases, the coolant source 346 may include a temperature control device for setting a desired temperature of the coolant 342. A controller 352 may be operably coupled to the valve 344, the coolant source 346, and / or the sensor 350 to control the quench system 314. The sensor 350 may be any suitable sensor for determining the temperature of the metal strip 310, such as the temperature of the metal strip 310 when it leaves the quench system 314. Based on the detected temperature, the controller 352 may adjust the temperature of the coolant 342 or the flow rate of the coolant 342 to maintain the temperature of the metal strip 310 within desired parameters (eg, less than 100° C.) as it exits the quenching system 314 .

[0058] The quenching system 314 can be positioned to begin cooling the metal strip 310 at a distance 348 downstream of where the metal strip 310 leaves the belt caster 308. The distance 348 can be as small as possible. In some cases, the distance 348 is at or less than 5 meters, 4 meters, 3 meters, 2 meters, 1 meter, 50 centimeters, 25 centimeters, 20 centimeters, 15 centimeters, 10 centimeters, 5 centimeters, 2.5 centimeters, or 1 centimeter.

[0059] The metal strip 310 leaving the quenching system 314 may have a desired distribution of dispersion forming elements and thus be in a desired state for subsequent dispersion formation (e.g., dispersion precipitation) as disclosed herein. The metal strip 310 leaving the quenching system 314 may be wound into an intermediate coil by a winding device.

[0060] Figure 4 is a schematic diagram depicting an intermediate coil vertical storage system 400 according to certain aspects of the present disclosure. The intermediate coil vertical storage system 400 may be Figure 1The storage system 104 of the present invention. The intermediate coil vertical storage system 400 can be used to store intermediate coils 412, such as intermediate coils 412 including metal strips 410 wound around shafts 452. The intermediate coils 412 can be lifted to a vertical orientation and then placed on a storage rack 454 having vertical supports 456. The vertical supports 456 can interact with the shafts 452 to firmly hold the intermediate coils 412 in a vertical orientation. In some cases, the vertical supports 456 can be extended protrusions that fit into the holes of the shafts 452, but other mechanisms can also be used. In some cases, the storage racks 454 can include shoulders 458 for keeping the metal strips 410 of the intermediate coils 412 spaced apart from the storage racks 454. In some cases, the intermediate coils 412 can include metal strips 410 without shafts, in which case the vertical supports 456 can fit into the center hole formed by the wound metal strips 410.

[0061] Figure 5 is a schematic diagram depicting an intermediate coil horizontal storage system 500 according to certain aspects of the present disclosure. The intermediate coil horizontal storage system 500 may be Figure 1 The storage system 104 of the intermediate coil horizontal storage system 500 can be used to store intermediate coils 512, such as intermediate coils 512 including metal strips 510 wound around shafts 552. The intermediate coil horizontal storage system 500 can include one or more horizontal supports 562 for horizontally supporting the shafts 552 of the intermediate coils 512. In some cases, the one or more horizontal supports 562 can be fixed to a single structure 564, such as a wall or other suitable structure.

[0062] In some cases, the intermediate coil 512 can rotate along the rotation direction 560 during storage. The rotation can occur periodically (e.g., once every ten minutes for 30 seconds) or continuously. In some cases, the horizontal support 562 can include a motor or other power source for rotating the intermediate coil 512.

[0063] In some cases, the intermediate coil 512 may include a metal strip 510 without an axis, in which case the horizontal support 562 may include an axis or other mechanism for supporting the intermediate coil 512 in a horizontal direction. In some cases, the horizontal support may support such an intermediate coil without an axis from a central hole formed by winding the metal strip 510, thereby avoiding the application of added weight to the portion of the metal strip 510 that is located below the hole under gravity. However, in some cases, the horizontal support 562 may include rollers or other such mechanisms for supporting the intermediate coil in a horizontal direction from below the bottom of the intermediate coil. In some cases, such rollers may facilitate the rotation of the intermediate coil.

[0064] Figure 6is a schematic diagram depicting a hot rolling system 600 according to certain aspects of the present disclosure. The hot rolling system 600 may be Figure 1 The hot rolling system 106 in FIG. The hot rolling system 600 can receive a metal strip 610, for example, in the form of an intermediate coil unwound by an unwinding device (e.g., an unwinder). The metal strip 610 can pass through various zones of the hot rolling system 600, such as an initial quenching zone 668, a hot rolling zone 670, a heat treatment zone 672, and a heat treatment quenching zone 674. The hot rolling system can include fewer or more zones.

[0065] In the initial quench zone 668, the metal strip 610 can be cooled to a hot rolling temperature suitable for hot rolling in the hot rolling zone 670. The hot rolling temperature can be at or about 350°C, but other values ​​can also be used. Any suitable heat extraction device can be used in the initial quench zone 668, such as an initial quench nozzle 678 that supplies an initial quench coolant 680 to the metal strip 610. Various controllers and sensors can be used to ensure that the heat extraction device is cooled by the desired amount. The initial quench zone 668 can be located upstream of the hot rolling zone 670, for example, immediately upstream of the hot rolling zone 670.

[0066] In the hot rolling zone 670, one or more hot rolling stands may reduce the thickness of the metal strip 610. Hot rolling may include reducing the thickness of the metal strip 610 while the metal strip 610 is at a hot rolling temperature (e.g., at or about 350° C.). Each hot rolling stand may include a pair of work rolls 682 in direct contact with the metal strip 610, and a pair of backing rolls 684 for applying rolling forces to the metal strip 610 via the work rolls 682. Other types of hot rolling stands may be used, such as a two-roll stand, a four-roll stand, a six-roll stand, or other stands having any suitable number of backing rolls (including zero). Various heat extraction devices may be used on the metal strip 610, the work rolls 682, and / or the backing rolls 684 to counteract the mechanically induced heat generated during the hot rolling process.

[0067] In the heat treatment zone 672, a heating device, such as a set of rotating magnetic heaters 688, can heat the metal strip 610. The metal strip can be heated to a heat treatment temperature in the heat treatment zone 672, such as at or about 500°C or higher. The heat treatment zone 672 can heat the metal strip 610 quickly after it leaves the hot rolling zone 670. Various controllers and sensors can be used to ensure that the heating device heats the metal strip 610 to the heat treatment temperature. The rotating magnetic heaters 688 can include an electromagnet or a permanent magnet rotor that rotates near the metal strip 610 without contacting the metal strip 610. These rotating magnetic heaters 688 can generate a changing magnetic field that can induce eddy currents in the metal strip 610, thereby heating the metal strip 610.

[0068] In some cases, the heating performed in the heat treatment zone 672 is performed entirely or partially by allowing the mechanically induced heat generated during hot rolling to heat the metal strip 610 toward, up to, or above the heat treatment temperature, typically during the hot rolling zone 670. Thus, any additional heating devices (e.g., rotating magnetic heaters 688) for the heat treatment zone 672 may be used to a lesser extent or eliminated from the hot rolling system 600.

[0069] In the heat treatment quench zone 674, the metal strip 610 can be rapidly cooled to a desired output temperature, such as at or about 100°C. In some cases, the metal strip can be cooled to below a desired coiling temperature (e.g., about 100°C), after which the metal strip can be reheated to a desired coiling temperature using any suitable reheating device (e.g., a rotating magnetic heater). The heat treatment quench zone 674 can be located immediately downstream of the heat treatment zone 672 and at a distance sufficient to ensure that the metal strip 610 remains at or above the heat treatment temperature for no longer than a desired duration, such as at or less than 5 seconds or at or less than 1 second. In some cases, the desired duration is as low as possible, minimizing the distance between the heat treatment zone 672 and the heat treatment quench zone 674. The heat treatment quench zone 674 may include one or more heat treatment quench nozzles 690 that supply a heat treatment quench coolant 692 to the metal strip 610. In some cases, the heat treatment quench coolant 692 is the same coolant as the initial quench coolant 680.

[0070] Throughout the hot rolling system 600 , various support rollers 686 may be employed to facilitate movement of the metal strip 610 through the hot rolling system 600 .

[0071] Figure 7 is a combination of a schematic diagram and a diagram depicting a hot rolling system 700 and an associated temperature profile 701 of a metal strip 710 being rolled thereon in accordance with certain aspects of the present disclosure. The hot rolling system 700 may be Figure 1 The hot rolling system 106 in.

[0072] The hot rolling system 700 includes a preheating zone 794, an initial quenching zone 768, a hot rolling zone 770, a heat treatment zone 772, and a heat treatment quenching zone 774 from upstream unwinding to downstream winding. The temperature curve 701 shows that the metal strip 710 can enter the hot rolling system 700 at a standard temperature (e.g., 350° C. as shown by the dashed line) or a preheating temperature (e.g., 530+° C. as shown by the dotted line). When entering at the preheating temperature, the preheating zone 794 can apply little or no additional heat to the metal strip 710. However, when entering at any temperature below the desired preheating temperature (e.g., at or above 530° C.), one or more heating devices in the preheating zone 794 can apply heat to the metal strip 710 to raise the temperature of the metal strip to or above the desired preheating temperature. As disclosed herein, preheating 795 of the metal strip 710 can improve the dispersion arrangement in the metal strip 710. In some cases, preheat zone 794 may include a set of rotating permanent magnets 788, although other heating devices may also be used.

[0073] Before entering the hot rolling zone 770, the metal strip 710 may undergo an initial quench 769 in an initial quench zone 768. In the initial quench zone 768, an initial quench coolant 780 supplied by one or more initial quench nozzles 778 may reduce the temperature of the metal strip 710 to a hot rolling temperature (e.g., at or about 350°C) for subsequent hot rolling 770.

[0074] During the hot rolling process in the hot rolling zone 770, the thickness of the metal strip 710 may be reduced due to the forces applied from the backing rolls 784 through the work rolls 782. To counteract the mechanically induced heat generated by hot rolling, one or more rolling coolant nozzles 796 may supply a rolling coolant 798 to one or more of the metal strip 710, the work rolls 782, or the backing rolls 784. Thus, as seen in the temperature profile 701, the temperature of the metal strip 710 may be maintained at or near the rolling temperature throughout the hot rolling zone 770.

[0075] At the heat treatment zone 772, the metal strip 710 may be heated 773 to a heat treatment temperature (e.g., at or above 500° C. or more). The heat treatment zone 772 may include a set of rotating permanent magnets 788, although other heating devices may be used. At the heat treatment quench zone 774, the metal strip 710 may be quenched 775 to a temperature below the hot rolling temperature, such as down to an output temperature (e.g., at or below 100° C.). The heat treatment quench zone 774 may cool the metal strip 710 by supplying a heat treatment quench coolant 792 from one or more heat treatment quench nozzles 790. In some cases, the initial quench coolant 780, the rolling coolant 798, and the heat treatment quench coolant 792 are from the same coolant source, but this is not necessarily the case.

[0076] Figure 8is a combination of a schematic diagram and a diagram depicting a hot rolling system 800 having an intentionally undercooled rolling stand and an associated temperature profile 801 of a metal strip 810 rolled thereon in accordance with certain aspects of the present disclosure. The hot rolling system 800 may be Figure 1 The hot rolling system 106 in.

[0077] The hot rolling system 800 includes a preheating zone 894, an initial quenching zone 868, a hot rolling zone 870, a heat treatment zone 872, and a heat treatment quenching zone 874 from upstream unwinding to downstream winding. The temperature curve 801 shows that the metal strip 810 can enter the hot rolling system 800 at a standard temperature (e.g., 350° C. as shown by the dashed line) or a preheating temperature (e.g., 530+° C. as shown by the dotted line). When entering at the preheating temperature, the preheating zone 894 can apply little or no additional heat to the metal strip 810. However, when entering at any temperature below the desired preheating temperature (e.g., at or above 530° C.), one or more heating devices in the preheating zone 894 can apply heat to the metal strip 810 to raise the temperature of the metal strip to or above the desired preheating temperature. As disclosed herein, preheating 895 of the metal strip 810 can improve the dispersion arrangement in the metal strip 810. In some cases, preheat zone 894 may include a set of rotating permanent magnets 888, although other heating devices may also be used.

[0078] Before entering the hot rolling zone 870, the metal strip 810 may undergo an initial quench 869 in an initial quench zone 868. In the initial quench zone 868, an initial quench coolant 880 supplied by one or more initial quench nozzles 878 may reduce the temperature of the metal strip 810 to a hot rolling temperature (e.g., at or about 350° C.) for subsequent hot rolling 870.

[0079] During the hot rolling process in the hot rolling zone 870, the thickness of the metal strip 810 may be reduced due to the force applied from the support rolls 884 through the work rolls 882. To counteract the mechanically induced heat generated by hot rolling, one or more rolling coolant nozzles 896 may supply rolling coolant 898 to one or more of the metal strip 810, the work rolls 882, or the support rolls 884. However, compared to Figure 7 800 includes an intentionally undercooled rolling stand. The rolling stand is intentionally undercooled by having the rolling coolant nozzles 896 apply less rolling coolant 898 than is required to completely offset the mechanically induced heat. Thus, as seen in the temperature profile 801, the temperature of the metal strip 810 may increase above the rolling temperature, e.g., toward, up to, or above a target heat treatment temperature, as it passes through the hot rolling zone 870. In some cases, instead of applying less rolling coolant 898, a rolling coolant 898 of a different temperature or a different mixture may be used to provide less heat extraction.

[0080] At the heat treatment zone 872, the metal strip 810 may be heated 873 to a heat treatment temperature (e.g., at or above 500° C. or more). The heat treatment zone 872 may include a set of rotating permanent magnets 888, although other heating devices may be used. When the hot rolling stand is intentionally undercooled, the heat treatment zone 872 may apply little or no additional heat to achieve the desired heat treatment temperature in the metal strip 810.

[0081] At the heat treatment quench zone 874, the metal strip 810 may be quenched 875 to a temperature below the hot rolling temperature, such as to an output temperature (e.g., at or below 100° C.). The heat treatment quench zone 874 may cool the metal strip 810 by supplying a heat treatment quench coolant 892 from one or more heat treatment quench nozzles 890. In some cases, the initial quench coolant 880, the rolling coolant 898, and the heat treatment quench coolant 892 are from the same coolant source, but this is not necessarily the case.

[0082] Fig. 9 is a combined flow chart and schematic diagram according to certain aspects of the present disclosure, which depicts a process 900 for casting and rolling a metal strip associated with a first variant 901A of a decoupling system and a second variant 901B of a decoupling system. At box 903, a metal strip can be cast using a continuous casting device (e.g., a belt caster). The metal strip can be cast at a first speed. At box 905, the metal strip can be stored, for example in the form of an intermediate coil. At box 907, the metal strip can be reheated to a reheating temperature or higher (e.g., at or about 550° C. or higher). In some cases, the reheating temperature can be at or about 400° C.-580° C. The metal strip can be reheated for a reheating time. In some cases, the reheating duration can be at or less than 6 hours, at or less than 2 hours, at or less than 1 hour, at or less than 5 minutes, or at or less than 1 minute. In some cases, the reheating duration can be selected to induce a desired amount of dispersion precipitation. At box 909, the metal strip can be hot rolled to reduce the thickness of the metal strip to a desired thickness. The metal strip may be hot rolled at a second speed different from the first speed. The second speed may be slower than the first speed. At optional block 911, the metal strip may be coiled for delivery.

[0083] Fig. 9 The right portion of is a schematic diagram depicting which blocks of the process 900 may be performed by certain subsystems of the first variant 901A of the decoupled casting and rolling system and the second variant 901B of the decoupled casting and rolling system.

[0084] In the first variant 901A, casting at box 903 is performed by casting system 902A. Storing the metal strip at box 905 and reheating the metal strip at box 907 are performed by storage system 904A. Hot rolling of the metal strip at box 909 and optional coiling of the metal strip at box 911 are performed by hot rolling system 906A.

[0085] In a second variation 901B, casting at box 903 is performed by casting system 902B. Bar storage at box 905 is performed by storage system 904B. Bar reheating at box 907, bar hot rolling at box 909, and optional bar coiling at box 911 are performed by hot rolling system 906B.

[0086] Fig.10 1 is a flow chart depicting a process 1000 for casting and rolling a metal strip according to certain aspects of the present disclosure. At block 1002, a continuous casting apparatus (e.g., a belt caster) casts a metal strip. The metal strip may be cast at a first speed. At block 1004, the metal strip may be rapidly quenched (e.g., rapidly cooled) upon exiting the continuous casting apparatus, such as immediately upon or shortly after exiting the casting apparatus. At block 1006, the metal strip may be coiled into an intermediate coil.

[0087] At block 1008, the intermediate coil may be stored. Storing the intermediate coil may optionally include storing the intermediate coil in a vertical or horizontal direction, and may optionally include hanging the intermediate coil and / or rotating the intermediate coil. At block 1008, the intermediate coil may optionally be preheated to a preheating temperature.

[0088] At block 1010, the metal strip may be unwound from the intermediate coil, such as by an unwinding device of a hot rolling system. At optional block 1014, the metal strip may be reheated to a reheating temperature. In the case where the intermediate coil is reheated to a reheating temperature at block 1008, reheating at block 1014 may be avoided.

[0089] At block 1016, the metal strip may be quenched to a hot rolling temperature. At block 1018, the metal strip may be hot rolled to a desired thickness. The metal strip may be hot rolled at a second speed different from the first speed. The second speed may be slower than the first speed.

[0090] At optional block 1020, the metal strip may be heated to a heat treatment temperature. Heating the metal strip to the heat treatment temperature may include rapidly applying heat to the metal strip immediately after or shortly after the metal strip leaves the hot rolling zone. Heating the metal strip to the heat treatment temperature may include rapidly applying heat to the metal strip in a short period of time. At block 1022, the metal strip may be rapidly quenched. Rapidly quenching the metal strip at block 1022 may stop the heat treatment of block 1020 after a desired duration. Rapidly quenching the metal strip at block 1022 may reduce the temperature of the metal strip to an output temperature, such as at or about 100° C. or less. At optional block 1024, the metal strip may be wound into a dispensable coil (e.g., a finished coil). At block 1024, the metal strip has the physical and / or chemical properties required for distribution to a customer (e.g., properties that match a desired specification).

[0091] Fig.11 1 is a graph 1100 depicting a temperature profile of a metal strip cast without post-casting quenching and stored at an elevated temperature prior to rolling in accordance with certain aspects of the present disclosure. The x-axis of the graph 1100 represents distance from an upstream direction toward a downstream direction (e.g., from left to right) along a decoupled continuous casting and rolling system. The y-axis of the graph 1100 is temperature (° C.). Line 1102 of the graph 1100 represents the approximate temperature of the metal as it moves along the decoupled continuous casting and rolling system. The metal strip is depicted as exiting the casting device at approximately 560° C., but in some cases, the metal strip may exit the casting device at a temperature between approximately 200° C. and 560° C., including approximately 350° C. and 450° C.

[0092] When post-casting quenching is not performed, the temperature of the metal strip leaving the casting device may not drop or only drop slightly before coiling. When preheating occurs between casting and hot rolling (e.g., preheating during storage), the metal strip can be maintained at an elevated temperature (e.g., at or about 530°C or higher) and can be supplied to the hot rolling system at or about that temperature. During hot rolling, the temperature of the metal strip can be reduced to the hot rolling temperature (e.g., at or about 350°C) for at least the duration of the metal strip passing through the rolling stands of the hot rolling system. The metal strip can be quickly reheated to a heat treatment temperature (e.g., at or about 500°C or higher) and then quenched to an output temperature (e.g., at or about 100°C or lower).

[0093] Fig.121 is a graph 1200 depicting a temperature profile of a metal strip cast without post-casting quenching and preheated prior to rolling according to certain aspects of the present disclosure. The x-axis of the graph 1200 represents distance from an upstream direction toward a downstream direction (e.g., from left to right) along a decoupled continuous casting and rolling system. The y-axis of the graph 1200 is temperature (° C.). Line 1202 of the graph 1200 represents the approximate temperature of the metal as it moves along the decoupled continuous casting and rolling system. The metal strip is depicted as exiting the casting device at approximately 560° C., but in some cases, the metal strip may exit the casting device at a temperature between approximately 200° C. and 560° C., including approximately 350° C. and 450° C.

[0094] When post-casting quenching is not performed, the temperature of the metal strip leaving the casting device may not drop or only drop slightly before coiling. When preheating is performed in-line in the hot rolling system (e.g., immediately before hot rolling), the metal strip may drop in temperature during storage and may enter the hot rolling system at about 350°C. In-line preheating in the hot rolling system can quickly raise the temperature of the metal strip to the preheating temperature (e.g., at or about 530°C or higher). Shortly after reheating, the metal strip can be quenched to the hot rolling temperature (e.g., at or about 350°C) and maintained at that temperature for at least the duration of the metal strip passing through the rolling stands of the hot rolling system. The metal strip can be quickly reheated to the heat treatment temperature (e.g., at or about 500°C or higher) and then quenched to the output temperature (e.g., at or about 100°C or lower).

[0095] Fig.13 13 is a graph 1300 depicting a temperature profile of a metal strip cast without post-casting quenching and stored at an elevated temperature prior to rolling in accordance with certain aspects of the present disclosure. The x-axis of the graph 1300 represents distance from an upstream direction toward a downstream direction (e.g., from left to right) along a decoupled continuous casting and rolling system. The y-axis of the graph 1300 is temperature (° C.). Line 1302 of the graph 1300 represents the approximate temperature of the metal as it moves along the decoupled continuous casting and rolling system. The metal strip is depicted as exiting the casting device at approximately 560° C., but in some cases, the metal strip may exit the casting device at a temperature between approximately 200° C. and 560° C., including approximately 350° C. and 450° C.

[0096] When post-casting quenching is performed, the temperature of the metal strip leaving the casting device can be rapidly reduced before coiling. Such rapid quenching can reduce the temperature of the metal strip to at or below about 500°C, 400°C, 300°C, 200°C, or 100°C. When preheating occurs between casting and hot rolling (e.g., preheating during storage), the metal strip can be heated to a high temperature (e.g., at or about 530°C or higher) and can be supplied to the hot rolling system at or near that temperature. During hot rolling, the temperature of the metal strip can be reduced to the hot rolling temperature (e.g., at or about 350°C) for at least the duration of the metal strip passing through the rolling stands of the hot rolling system. The metal strip can be rapidly reheated to a heat treatment temperature (e.g., at or about 500°C or higher) and then quenched to an output temperature (e.g., at or about 100°C or lower).

[0097] Fig.14 14 is a graph 1400 depicting a temperature profile of a metal strip cast with post-casting quenching and preheated prior to rolling, according to certain aspects of the present disclosure. The x-axis of the graph 1400 represents distance from an upstream direction toward a downstream direction (e.g., from left to right) along a decoupled continuous casting and rolling system. The y-axis of the graph 1400 is temperature (° C.). Line 1402 of the graph 1400 represents the approximate temperature of the metal as it moves along the decoupled continuous casting and rolling system. The metal strip is depicted as leaving the casting device at approximately 560° C., but in some cases, the metal strip may leave the casting device at a temperature between approximately 200° C. and 560° C., including approximately 350° C. and 450° C.

[0098] When post-casting quenching is performed, the temperature of the metal strip leaving the casting device can be rapidly reduced before coiling. This rapid quenching can reduce the temperature of the metal strip at a temperature at or below about 500°C, 400°C, 300°C, 200°C, or 100°C. Depending on the temperature of the metal strip during coiling, the metal strip may be cooled or heated during coiling. The metal strip can enter the hot rolling system at about 350°C, but in some cases, it can enter the hot rolling system at a temperature below the temperature. In-line preheating in the hot rolling system can quickly raise the temperature of the metal strip to the preheating temperature (e.g., at or about 530°C or higher). Shortly after reheating, the metal strip can be quenched to the hot rolling temperature (e.g., at or about 350°C) and maintained at the temperature for at least the duration of the metal strip passing through the rolling stands of the hot rolling system. The metal strip can be rapidly reheated to the heat treatment temperature (e.g., at or about 500°C or higher) and then quenched to the output temperature (e.g., at or about 100°C or lower).

[0099] Fig.15is a set of magnified images depicting ferrous (Fe-containing) intermetallics in aluminum alloy AA6014 for standard DC cast metal strip 1500 compared to metal strip 1501 cast using a decoupled casting and rolling system according to certain aspects of the present disclosure. Metal strip 1500 was produced according to standard direct cool casting techniques, including long heat treatment times (e.g., on the order of hours or days). Metal strip 1501 was produced according to certain aspects of the present disclosure.

[0100] When comparing the images of metal strips 1500 and 1501, DC cast metal strip 1500 shows many large intermetallic compounds that are tens of microns in size, while the intermetallic compounds found in metal strip 1501 are much smaller, with even the largest intermetallic compounds measuring less than a few microns in length. The different arrangement of these intermetallic compounds indicates that solidification in DC cast metal strip 1500 occurs relatively slowly compared to solidification in metal strip 1501. In fact, solidification of metal strip 1501 occurs at a rate that is approximately 100 times faster than the solidification rate of DC cast metal strip 1500.

[0101] Fig.16 is a set of scanning transmission electron micrographs depicting dispersion in a 6xxx series aluminum alloy metal strip reheated at 550° C. for one hour compared to a metal strip 1601 cast without a post-casting quench and a metal strip 1600 cast with a post-casting quench according to certain aspects of the present disclosure. Using a continuous casting system as described herein, for example Figure 1 The continuous casting system 102 prepares each metal strip 1600, 1601. However, the casting system for the metal strip 1600 includes a rapid quenching system, such as Figure 3 The rapid quenching system 314 is provided, while the casting system for the metal strip 1601 does not include a rapid quenching system.

[0102] Metal strip 1601 exits the belt caster at about 450°C and is allowed to air cool to about 100°C over a period of 3 hours. Metal strip 1600 exits the belt caster at about 450°C and is immediately quenched to 100°C in about 10 seconds or less. Both metal strip 1601 and metal strip 1600 are reheated in a conventional resistance furnace that is preheated at 550°C for one hour.

[0103] The dispersion arrangement of metal strip 1601 shows only a few dispersions of the desired size, most of which are either too large or too small. In contrast, the dispersion arrangement of metal strip 1600 shows a well-distributed arrangement of dispersions of the desired size. The average diameter of the dispersions of the desired size can be between 10 nm and 500 nm or between 10 nm and 100 nm. For reference purposes, a 50 nm point (e.g., a medium desired dispersion) and a 100 nm point (e.g., the largest desired dispersion) are depicted on the left side of each micrograph at the approximate scale of the micrograph.

[0104] Due to the quenching immediately after continuous casting, the precursor metal strip of metal strip 1600 (e.g., before reheating as shown) includes many small and well-dispersed dispersion forming elements that remain supersaturated within the aluminum matrix. This matrix supersaturated with dispersion forming elements serves as a substrate that can be reheated to produce Fig.16 1601 is uniquely advantageous. When the precursor metal strip of metal strip 1600 is reheated, the dispersion begins to precipitate from the supersaturated matrix into the desired dispersion arrangement depicted. In contrast, without post-casting quenching, the dispersion arrangement of metal strip 1601 is not well distributed and includes undesirably large dispersions.

[0105] Fig.17 is a graph 1700 comparing yield strength and three-point bend test results for 7xxx series metal bars produced using conventional direct cooling techniques and using decoupled continuous casting and rolling according to certain aspects of the present disclosure. Graph 1700 shows that by using the decoupled continuous casting and rolling system disclosed herein, the same three-point bend characteristics can be achieved while achieving substantially improved (e.g., 15% improvement) yield strength compared to conventional direct cooling casting techniques.

[0106] Fig.18 1800 is a graph comparing yield strength and solution heat treatment soaking time results for 6xxx series metal bars produced using conventional direct cooling techniques and using decoupled continuous casting and rolling according to certain aspects of the present invention. Graph 1800 shows that for metal casting using conventional direct cooling techniques, the desired yield strength characteristics (e.g., at or near 290 MPa) typically require a soaking time of at least 60 seconds at the solution temperature (e.g., at or about 520° C.). However, for metal casting using the decoupled continuous casting and rolling system disclosed herein, the desired yield strength characteristics can be achieved with a zero second soaking time at the solution temperature.

[0107] Conventional DC casting techniques require this 60 second soaking time to put the various strengthening particles back into solution. However, due to the desired arrangement of particles in the metal casting according to various aspects of the present disclosure, the desired strength can be achieved by simply heating the metal strip to the solution temperature without holding the metal at that temperature for more than a few seconds, a second, or even 0.5 seconds.

[0108] This huge savings in soaking time is particularly important when it is desired to perform solution heat treatment in-line with a hot rolling mill. Because the metal strip may be moving at speeds of about 300 m / min to 800 m / min or more at the exit of the hot rolling stand, the amount of processing line required to provide a 60 second soak for a DC cast metal strip may exceed 300-800 meters. In contrast, the amount of processing line required to provide the required soaking time for a metal strip prepared according to various embodiments of the present disclosure may be negligible. This distance may be virtually zero or as low as the minimum distance required between the heating device (e.g., a rotating magnetic heater) and the quenching device directly downstream thereof.

[0109] Fig.19 is a set of scanning transmission electron micrographs depicting dispersion in an AA6111 aluminum alloy metal strip reheated at 550° C. for eight hours compared to a metal strip 1901 cast without post-casting quenching and a metal strip 1900 cast with post-casting quenching according to certain aspects of the present disclosure. Using a continuous casting system as described herein, for example Figure 1 The continuous casting system 102 prepares each metal strip 1900, 1901. However, the casting system for the metal strip 1900 includes a rapid quenching system, such as Figure 3 The rapid quenching system 314 is provided, while the casting system for the metal strip 1901 does not include a rapid quenching system.

[0110] Metal strip 1901 exits the belt caster at about 450°C and is allowed to air cool to about 100°C over a period of 3 hours. Metal strip 1900 exits the belt caster at about 450°C and is immediately quenched (e.g., quenched to 100°C in about 10 seconds or less). Both metal strips 1901 and 1900 are slowly reheated to 540°C at a rate of 50°C / hour and held at 540°C for eight hours.

[0111] The dispersion arrangement of metal strip 1901 shows a coarse dispersion and only a few dispersions of the desired size. In contrast, the dispersion arrangement of metal strip 1900 shows a well-distributed arrangement of many dispersions of the desired size. The average diameter of the dispersions of the desired size can be between 10 nm and 500 nm or between 10 nm and 100 nm. For reference purposes, a 50 nm dot (e.g., a medium desired dispersion), a 100 nm dot, and a 500 nm dot are depicted on the left side of each micrograph at the approximate scale of the micrograph.

[0112] Due to the quenching immediately after continuous casting, the precursor metal strip of metal strip 1900 (e.g., before reheating as shown) includes many small and well-dispersed dispersion forming elements that remain supersaturated within the aluminum matrix. This matrix supersaturated with dispersion forming elements serves as a substrate that can be reheated to produce Fig.19 1900 is uniquely advantageous. When the precursor metal strip of metal strip 1900 is reheated, the dispersion begins to precipitate from the supersaturated matrix into the desired dispersion arrangement depicted. In contrast, without post-casting quenching, the dispersion arrangement of metal strip 1901 is not as well distributed and includes fewer and coarser dispersions.

[0113] Fig. 20 2000 is a graph depicting precipitation of Mg2Si during hot rolling and quenching of an aluminum metal strip according to certain aspects of the present invention. Graph 2000 depicts expected Mg2Si precipitation as a function of time spent at certain temperatures for an aluminum alloy (e.g., a 6xxx series aluminum alloy). A high precipitation region 2001 is shown. The boundaries of high precipitation region 2001 represent expected Mg2Si precipitation between 1% and 90% (e.g., between 0.01 and 0.9 volume fractions). Thus, when a line passes through the left edge of high precipitation region 2001, the metal following the line is expected to have approximately 1% Mg2Si precipitation, which will grow until the line passes through the right edge of high precipitation region 2001, at which point the metal following the line is expected to have at least 90% Mg2Si precipitation. For example, metal held at about 400° C. for up to about 1.7 seconds is expected to have about 1% or less Mg2Si precipitation, and if held at that temperature for 407 seconds, at least 90% Mg2Si precipitation is expected. In the high precipitation zone 2001, precipitation of Mg2Si occurs rapidly, moving quickly from 1% to 90% precipitation. Therefore, in some cases, it may be desirable to minimize the amount of time the metal strip spends in the high precipitation zone 2001. In some cases, it may be desirable to leave the high precipitation zone 2001 after a specific amount of time calculated to achieve a desired volume fraction of Mg2Si precipitation or any other precipitation.

[0114] Line 2003 describes the temperature of the metal strip immediately before, during, and after hot rolling (including quenching), where the metal strip is preheated and cooled before hot rolling, rolled at a hot rolling temperature below the recrystallization temperature, then heated after hot rolling, and finally quenched. Line 2003 can track the temperature of the metal strip, for example Figure 7 The temperature of the metal strip 710 as it passes through the initial quenching zone 768, the hot rolling zone 770, the heat treatment zone 772 and the heat treatment quenching zone 774.

[0115] Line 2003 shows the initial drop in temperature to the hot rolling temperature. The metal strip is maintained at the hot rolling temperature throughout the hot rolling process, which may include passing through a first rolling stand 2007, a second rolling stand 2009, and a third rolling stand 2011. It should be noted that line 2003 is within the high precipitation zone 2001 of Mg2Si as the metal strip passes through the second rolling stand 2009 and the third rolling stand 2011. Line 2003 can show a metal strip that is heat treated after hot rolling and then quenched. Point 2005 depicts when quenching begins.

[0116] Line 2003 enters high precipitation zone 2001 at about 2.5 seconds and leaves high precipitation zone 2001 at about 19.2 seconds, thus spending about 16.7 seconds in high precipitation zone 2001. In some cases, line 2003 briefly leaves high precipitation zone 2001 near the end of the heat treatment as the temperature rises above the leftmost edge of high precipitation zone 2001 and then rapidly cools as quenching begins.

[0117] Line 2013 describes the temperature of the metal strip immediately before, during, and after hot rolling (including quenching), where the metal temperature gradually cools during hot rolling before the final quenching. Line 2013 can track the temperature of the metal strip as follows Fig.21 The temperature of the metal strip 2110 as it passes through the hot rolling zone 2170 and the heat treatment quenching zone 2174.

[0118] Line 2013 shows little or no initial quenching prior to hot rolling. More specifically, during hot rolling, the metal strip is dropped from a hot rolling inlet temperature above the recrystallization temperature (e.g., a preheat temperature, e.g., at or above 530° C.) to a hot rolling outlet temperature below the hot rolling inlet temperature. To achieve the temperature reduction during hot rolling depicted in line 2013, each stand of the hot rolling mill can extract heat from the metal strip. During the heat treatment process, the metal strip can undergo dynamic recrystallization during the hot rolling process, rather than relying on post-rolling (e.g., after hot rolling) recrystallization during the heat treatment process. Line 2013 can track a monotonically decreasing path from immediately before the first hot rolling stand to immediately after the quenching process.

[0119] It may be necessary to control the precipitation of precipitates (e.g., Mg2Si). In some cases, the amount of precipitation may be minimized or controlled to a preset desired amount. For example, when it is necessary to minimize precipitation, the amount of time spent in the high precipitation zone 2001 may be minimized. In order to minimize the amount of time spent in the high precipitation zone 2001, the metal strip may leave the final hot rolling stand at the hot rolling exit temperature, and may then be rapidly quenched to a temperature below which a large amount of precipitation is expected (e.g., quenched to a temperature below the high precipitation zone 2001, maintaining the specific time range). Therefore, it may be necessary to minimize the hot rolling exit temperature and / or maximize the cooling rate during quenching. As described herein, it may be necessary to maximize the reduction (e.g., thickness reduction percentage) of the final hot rolling stand (e.g., the third hot rolling stand 2021), or at least select a reduction suitable for achieving a hot rolling exit temperature suitable for rapid quenching to minimize the time spent in the high precipitation zone 2001. For example, in some cases, the reduction amount performed at each of the first hot rolling stand 2017, the second hot rolling stand 2019, and the third hot rolling stand 2021 may be a 50% reduction (e.g., from 16 mm to 8 mm, then from 8 mm to 4 mm, then from 4 mm to 2 mm). In some cases, the reduction amount performed at the third hot rolling stand 2021 may be greater than 40%, 45%, 50%, 55%, 60%, 65%, or 70%.

[0120] The hot rolling exit temperature may be any suitable temperature. In some cases, it may be desirable to remove a significant amount of heat during the hot rolling process so that the metal leaves the final hot rolling stand at a hot rolling exit temperature at or below 450°C, 445°C, 440°C, 435°C, 430°C, 425°C, 420°C, 415°C, 410°C, 405°C, 400°C, 395°C, 390°C, 385°C, 380°C, 375°C, 370°C, 365°C, 360°C, 355°C, 350°C, 345°C, 340°C, 335°C, 330°C, 325°C, 320°C, 315°C, 310°C, 305°C, or 300°C. In some cases, it may be desirable for the hot rolling exit temperature to be between about 375°C and 405°C, 380°C and 400°C, 385°C and 395°C, or about 390°C. Dynamic recrystallization can occur within the metal strip during hot rolling by entering the first hot rolling stand 2017 at a temperature above the recrystallization temperature and reducing the temperature as the metal strip passes through the second hot rolling stand 2019 and the third hot rolling stand 2021 to the hot rolling exit temperature. Other numbers of rolling stands may be used.

[0121] As depicted in graph 2000, line 2013 enters high precipitation region 2001 at approximately 3.1 seconds and leaves high precipitation region 2001 at approximately 7.4 seconds, thus spending approximately 4.3 seconds in high precipitation region 2001. Thus, the duration of time in high precipitation region 2001 of line 2013 may be approximately 25% of the duration of time in high precipitation region 2001 of line 2003. This difference in duration may significantly affect the amount of precipitation of Mg2Si or other precipitates. Although graph 2000 depicts the precipitation of Mg2Si, similar graphs exist for other precipitates, and similar principles may apply.

[0122] Fig.21 is a combined schematic diagram and diagram depicting a hot rolling system 2100 and an associated temperature profile 2101 of a metal strip 2110 being rolled thereon, in accordance with certain aspects of the present disclosure. The hot rolling system 2100 may be Figure 1 The hot rolling system 106 in the embodiment of the present invention can be based on the Fig. 20 An overview of the principles of the line 2013 to operate.

[0123] The hot rolling system 2100 includes an optional preheating zone 2194, a hot rolling zone 2170, and a quenching zone 2174 from upstream unwinding to downstream coiling. The temperature curve 2101 shows that the metal strip 2110 can enter the hot rolling system 2100 at a standard temperature (e.g., 350° C. as shown by the dashed line) or a preheating temperature (e.g., 530+° C. as shown by the dotted line). When entering at the preheating temperature, the preheating zone 2194 can apply little or no additional heat to the metal strip 2110. However, when entering at any temperature below the desired preheating temperature (e.g., at or above 530° C.), one or more heating devices in the preheating zone 2194 can apply heat to the metal strip 2110 to raise the temperature of the metal strip to or above the desired preheating temperature. As disclosed herein, preheating 2195 of the metal strip 2110 can improve the dispersion arrangement in the metal strip 2110. In some cases, preheat zone 2194 may include one or more sets of rotating permanent magnets 2188, although other heating devices may also be used.

[0124] The metal strip 2110 undergoes little or no initial quenching prior to entering the hot rolling zone 2170. Thus, when entering the hot rolling zone 2170, the metal strip 2110 may have an elevated temperature (eg, at or greater than about 530°C).

[0125] During the hot rolling process in the hot rolling zone 2170, the thickness of the metal strip 2110 may be reduced due to the force applied from the support rolls 2184 through the work rolls 2182. In order to counteract the mechanically induced heat generated by hot rolling and provide a cooling effect to the metal strip 2110, one or more rolling coolant nozzles 2196 may supply a rolling coolant 2198 to one or more of the metal strip 2110, the work rolls 2182, or the support rolls 2184. The coolant 2198 may be any suitable coolant, such as lubricating oil, air, water, or a mixture thereof. Thus, as seen in the temperature curve 2101, the temperature of the metal strip 2110 may be monotonically reduced throughout the hot rolling zone 2170 from the hot rolling inlet temperature (e.g., at or above about 530°C) to the hot rolling exit temperature (e.g., at or about 400°C) below the hot rolling inlet temperature. In some cases, it may be desirable to minimize the hot rolling exit temperature while ensuring that dynamic recrystallization occurs. This minimization can be achieved by maintaining a high strain rate in the final rolling stand, for example by relatively high speed rolling with relatively high thickness reduction.

[0126] The metal strip 2110 may be quenched immediately after leaving the hot rolling zone 2170 (e.g., without reheating). At the quenching zone 2174, the metal strip 2110 may be quenched 2175 to a temperature below the hot rolling exit temperature, such as to an output temperature (e.g., at or below 100° C.). The heat treatment quenching zone 2174 may cool the metal strip 2110 by supplying a quench coolant 2192 from one or more quench nozzles 2190. In some cases, the rolling coolant 2198 and the quench coolant 2192 come from the same coolant source, but this is not necessarily the case.

[0127] Fig. 22 2 is a schematic diagram depicting a tropical continuous casting system 2200 according to certain aspects of the present disclosure. The tropical continuous casting system 2200 may be a partially decoupled continuous casting system similar to Figure 3 The decoupled continuous casting system 300 has several in-line additions to improve certain metallurgical properties. The hot strip continuous casting system 2200 can produce a coiled hot strip 2212, which is optionally in final specifications and optionally in final tempered state. In some cases, the hot strip 2212 can be used as an intermediate coil and undergo further processing as described herein. However, in some cases, the hot strip 2212 itself can be a final product, with desired specifications and optional tempered state.

[0128] The tropical continuous casting system 2200 includes a continuous casting device, such as a twin-belt caster 2208, although other continuous casting devices, such as a twin-roll caster, can be used. The belt caster 2208 includes a relative belt that can extract heat from the liquid metal 2236 at a cooling rate sufficient to solidify the liquid metal 2236, and the liquid metal is discharged from the belt caster 2208 as a metal strip 2210 once solidified. The thickness of the metal strip 2210 when leaving the belt caster 2208 can be 50mm or less, but other thicknesses can also be used. The belt caster 2208 can operate at a desired casting speed. The relative belt can be made of any suitable material, but in some cases, the belt is made of copper. The cooling system in the belt caster 2208 can extract enough heat from the liquid metal 2236 so that the metal strip 2210 leaving the belt caster 2208 has a temperature between 200°C and 530°C, but other ranges can also be used. In some cases, the temperature (eg, peak metal temperature) exiting the belt caster 2208 can be at or about 350°C-450°C.

[0129] In some cases, an optional soaking furnace 2217 (e.g., a tunnel furnace) can be located downstream of the belt caster 2208 near the outlet of the belt caster 2208. Using the soaking furnace 2217 can help to obtain a uniform temperature profile across the lateral width of the metal strip 2210. In addition, the soaking furnace 2217 can flash homogenize the metal strip 2210, which can prepare the metal strip 2210 to improve the crushing of iron components during hot rolling or warm rolling. In some cases, an optional pinch roll 2215 can be located between the belt caster 2208 and the soaking furnace 2217. In some cases, an optional set of magnetic heaters 2288 (e.g., a magnetic rotor or magnet rotating around a rotation axis) can be located between the belt caster 2208 or the pinch rolls 2215 and the soaking furnace 2217. The magnetic heater 2288 can raise the temperature of the metal strip 2210 to at or about the temperature of the soaking furnace 2217, which can be about 570° C. (e.g., 500-570° C., 520-560° C., or at or about 560° C. or 570° C.). The soaking furnace 2217 can have a sufficient length to allow the metal strip 2210 to pass through the soaking furnace 2217 in at or about 1 minute to 10 minutes, or more preferably at or between 1 minute and 3 minutes, or more preferably at or about 2 minutes, while moving at the exit speed of the belt caster 2208.

[0130] In some cases, the rolling stand 2284 can be located downstream of the soaking furnace 2217 and upstream of the coiling equipment. The rolling stand 2284 can be a hot rolling stand or a warm rolling stand. In some cases, warm rolling is performed at a temperature at or below 400°C but above the cold rolling temperature, and hot rolling is performed at a temperature above 400°C but below the melting temperature. The hot rolling stand 2284 can reduce the thickness of the metal strip 2210 by at least 30%, or more preferably between 50% and 75%. The post-rolling quench 2219 can reduce the temperature of the metal strip 2210 after it leaves the rolling stand 2284. The post-rolling quench 2219 can impart beneficial metallurgical properties, such as those described in detail in detail in conjunction with FIG. Figure 3 The dispersion forms related properties. In some cases, more than one rolling stand 2284 may be used, such as two, three or more, but this is not necessarily the case.

[0131] In some cases, the optional pre-rolling quench 2213 can reduce the temperature of the metal strip 2210 between the soaking furnace 2217 and the rolling stand 2284, which can impart beneficial metallurgical properties to the metal strip 2210. The pre-rolling quench 2213 and / or the post-rolling quench 2219 can reduce the temperature of the metal strip 2210 at a rate of at or about 200° C. / second. The pre-rolling quench 2213 can reduce the peak metal temperature of the metal strip 2210 to at or about 350° C.-450° C., although other temperatures can also be used.

[0132] Before coiling, the metal strip 2210 may be edge trimmed by an edge trimmer 2221. During coiling, the metal strip 2210 may be coiled into a coil of a heat strip 2212, and a shear 2223 may separate the metal strip 2210 when the coil of the heat strip 2212 has reached a desired length or size. In some cases, the heat strip 2212 may not be coiled, but may be provided directly to another process. In some cases, the coiling may be performed at a temperature at or about 50° C. to 400° C.

[0133] As indicated by box 2286, the hot strip 2212 may be at final gauge. In this case, the rolling stand 2284 may be configured to reduce the thickness of the metal strip 2210 to the final gauge required for the hot strip 2212. In some cases, the hot strip 2212 may be at final gauge and tempered, as indicated by box 2287. In this case, the rolling stand 2284 may be configured to reduce the thickness of the metal strip 2210 to the final gauge required for the hot strip 2212, and the temperature may be carefully controlled by the hot strip continuous casting system 2200 to achieve the desired temper, such as the O temper or the T4 temper, but other tempers may also be used. In some cases, the hot strip 2212 may be stored, optionally reheated (as noted above with reference to the intermediate coil), and then finished, cold rolled and / or heat treated, as indicated by box 2289. The hot strip 2212 produced using the hot strip continuous casting system 2200 may have a microstructure that is more suitable for cold rolling. For example, 6xxx series aluminum alloy hot rolled strip produced using the tropical continuous casting system 2200 may have smaller and more spherical intermetallics that respond more favorably to cold rolling than standard intermetallics that may cause problematic voids and crack initiation sites when cold rolled.

[0134] In some cases, hot band 2212 may include the desired iron particle distribution (e.g., iron component fragmentation and spheroidization) in 6xxx and 5xxx series aluminum alloys when the metal strip 2210 is allowed to soak in soaking furnace 2217, inline after continuous casting, wherein the continuous casting is continued for at least at or about 1.5 minutes or 2 minutes at a peak metal temperature of at or about 560°C or 570°C prior to hot or warm rolling, and the thickness is reduced to at or about 50%-70%. The iron particle distribution can play an important role in the crack initiation sites and deformability of the metal product made using hot band 2212. Using certain aspects of the present disclosure, hot band 2212 can be made with highly fragmented and spheroidized iron components, thereby resulting in improved deformability and lower cracking susceptibility.

[0135] In some alternative embodiments, the rolling stand 2284 can be located upstream (e.g., to the left of) the soaking furnace 2217. Fig. 22 ). While such a location may produce the desired results, the increased speed of the metal strip 2210 resulting from the relatively high thickness reduction (e.g., 50%-70%) may result in a longer soaking furnace 2217 and thus higher installation costs, operating costs, and physical footprint. In some alternative embodiments, additional soaking furnaces may be located downstream of the rolling stand 2284 to further control the temperature of the metal strip 2210 after thickness reduction. However, again, the increased speed of the metal strip after rolling may result in additional soaking furnaces having a relatively large footprint and higher associated costs.

[0136] Fig.23 is a graph 2300 depicting precipitation of Mg2Si during hot rolling and quenching of an aluminum metal strip according to certain aspects of the present disclosure. Graph 2300 is similar to Fig. 20 2000, depicting the expected precipitation of Mg2Si based on the time spent at certain temperatures for an aluminum alloy (e.g., a 6xxx series aluminum alloy). A high precipitation region 2301 is shown, with Fig. 20 The high precipitation area is similar to 2001.

[0137] Line 2303 depicts the temperature of a metal strip processed according to certain aspects of the present disclosure, where the metal strip is cooled to a warm rolling temperature, warm rolled while further cooling, and then further cooled. Warm rolling while further cooling occurs at section 2307. By controlling the time and temperature of the metal strip so that temperature line 2303 remains outside of high precipitation zone 2301, precipitation of Mg2Si can be minimized.

[0138] In some cases, the metal strip may pass through two mill stands while being warm rolled. In the first bite (e.g., between the rolls of the first mill stand), the metal strip may be quenched to a sufficiently low temperature to avoid precipitation of undesirable intermetallic compounds (e.g., Mg2Si). In the second bite, the thickness of the metal strip may be reduced with sufficient force to recrystallize at the temperature of the metal strip upon entering the second bite.

[0139] Line 2305 depicts the temperature of a metal strip processed according to certain aspects of the present disclosure, where the metal strip is maintained at an elevated temperature (e.g., at or above about 510° C., 515° C., or 517° C.) from casting to rolling. After rolling, the metal strip can be rapidly quenched, thereby minimizing the amount of time that the temperature line 2305 of the metal strip remains in the high precipitation zone 2301. In this case, the metal strip can maintain a non-work-hardened grain structure due, at least in part, to the elevated temperatures during rolling.

[0140] Fig.24 24 is a flow chart depicting a process 2400 for casting a hot metal strip according to certain aspects of the present disclosure. At block 2402, a metal strip may be cast using a continuous casting apparatus, such as a belt caster. Using a continuous casting apparatus, such as a belt caster, may ensure a fast solidification rate.

[0141] In optional block 2404, after exiting the belt caster, the metal strip can be flash homogenized. Flash homogenization can include optionally reheating the metal strip to a soaking temperature (e.g., at or about 400° C.-580° C., or more preferably at or about 570° C.-580° C.) and maintaining the metal strip at the soaking temperature for a period of time. The duration can be at or about 10-300 seconds, 60-180 seconds, or 120 seconds.

[0142] Flash homogenization can be particularly useful for breaking up and / or spheroidizing large and / or blade-shaped intermetallic compounds. For example, AA6111 and AA6451 alloys may have relatively large intermetallic compounds when cast, which can be significantly improved by flash homogenization as disclosed herein. However, AA5754 alloy may not be produced in the form of needle-shaped or blade-shaped intermetallic compounds, so AA5754 and similar alloys can omit flash homogenization. In some cases, it can be determined based on the ratio of iron to silicon when to use flash homogenization and when not to use flash homogenization, where alloys with higher silicon content (e.g., a silicon to iron ratio of 1:5 or more) can benefit from flash homogenization. In some cases, alloys with lower silicon content (e.g., a silicon to iron ratio of 1:5 or less) can be ideally cast at lower temperatures (e.g., at or about 500°C-520°C) without flash homogenization or with flash homogenization.

[0143] In some cases, flash homogenization can be performed at lower temperatures for certain alloys. For example, 7xxx series alloys can be successfully flash homogenized at temperatures at or about 350°C-480°C.

[0144] At optional block 2406, the metal strip may be cooled prior to hot or warm rolling. In some cases, particularly where it is desired to control the precipitation of chromium, it may be beneficial to cool the metal strip prior to hot or warm rolling. The cooling at block 2406 may include cooling the metal strip to a temperature at or about 350° C.-450° C., although other temperatures may also be used.

[0145] At block 2408, the metal strip may be hot rolled or warm rolled at a thickness reduction of at least about 30% and less than about 80%. In some cases, the thickness reduction may be at least about 50%, 55%, 60%, 65%, 70%, or 75%. In some cases, the hot rolling or warm rolling at block 2408 may optionally include quenching the metal strip during rolling (e.g., within the nip between the rolls of a rolling mill stand), but this need not be the case. In some cases, the hot rolling or warm rolling at block 2408 is performed while the metal strip is maintained at a temperature at or above 500° C., 505° C., 510° C., 515° C., 520° C., or 525° C.

[0146] At block 2410, the metal strip may be quenched after hot or warm rolling. The quenching at block 2410 may include cooling the metal strip at a high rate (e.g., 200°C / second), although other rates may be used. The quenching at block 2410 may reduce the temperature of the metal strip to at or about 50°C-400°C, such as 50°C-300°C, although other temperatures may be used.

[0147] At block 2412, the metal strip may be coiled into a hot strip. The hot strip may be in a final gauge and tempered state, in a final gauge, or in an intermediate gauge. If in a final gauge and tempered state or in a final gauge, the coiled hot strip may be delivered to a customer for further use in its intended use. If in an intermediate gauge, the hot strip may be reheated, rolled (e.g., cold rolled or hot rolled), heat treated, or otherwise processed into a final product for delivery to a customer.

[0148] At optional block 2414, the hot strip may be reheated to further improve metallurgical properties as described herein, including in the examples below.

[0149] Fig.25 is a schematic diagram depicting a tropical continuous casting system 2500 according to certain aspects of the present disclosure. The tropical continuous casting system 2500 may be used with Fig. 22 The tropical continuous casting system 2200 is the same or similar to the tropical continuous casting system 2200, but has an additional feed reel 2513. The tropical continuous casting system 2500 can operate in a casting mode and a processing mode. In the casting mode, the tropical continuous casting system 2500 can utilize the belt continuous casting machine 2508 to produce a metal strip 2510, which can then be directed through various components of the tropical continuous casting system 2500, such as Fig. 22 The tropical continuous casting system 2200 described includes passing the metal strip 2510 through a rolling stand 2584.

[0150] However, in the processing mode, the hot strip continuous casting system 2500 can provide the metal strip 2510 (e.g., not a hot strip of final specification) from the additional feed coil 2513 to one or more components (including at least the rolling stand 2584) of the hot strip continuous casting system 2500. After rolling (e.g., hot rolling or hot rolling), the metal strip 2510 from the additional feed coil 2513 can be wound into a coil of the hot strip 2512.

[0151] Thus, the same rolling stand 2584 can be used for inline rolling of just continuously cast metal strips, as well as rolling of previously cast and coiled metal strips 2510. Operation of the hot strip continuous casting system 2500 in process mode can be particularly useful when the continuous casting apparatus needs repair or is awaiting preparation of liquid metal 2536.

[0152] Fig.26 2600 is a schematic diagram depicting a continuous casting system 2600 according to certain aspects of the present disclosure. The continuous casting system 2600 may be similar to Fig. 22 The hot strip continuous casting system 2200 of FIG. 20 is similar to that of FIG. 20 , but uses a continuous casting device 2608 to cast an extrudable metal product 2610 (e.g., a billet) instead of a continuous casting machine for casting metal strip. The extrudable metal product 2610 can be cast using the same method as described in reference to FIG. Fig. 22 The metal strip 2210 may be subjected to the same or similar process as described above in the same or similar equipment, but the rolling stand may be replaced with the mold 2684. The continuous casting system 2600 may produce a coiled product 2612. Fig. 22 Similar to the hot strip 2212, the wound product 2612 can be in final gauge, in final gauge and tempered state, or can be in intermediate gauge for further processing.

[0153] Fig. 27 2700 is a flow chart depicting a process 2700 for casting an extruded metal product according to certain aspects of the present disclosure. At block 2702, a continuous casting apparatus may be used to cast an extrudable metal product, such as a billet. Using a continuous casting apparatus may ensure a fast solidification rate.

[0154] At optional block 2704, the extrudable metal product can be flash homogenized after exiting the casting device. Flash homogenization can include optionally reheating the extrudable metal product to a soaking temperature (e.g., at or about 400° C.-580° C., or more preferably at or about 570° C.-580° C.), and maintaining the extrudable metal product at the soaking temperature for a period of time. The duration can be at or about 10-300 seconds, 60-180 seconds, or 120 seconds.

[0155] Flash homogenization can be particularly useful for breaking up and / or spheroidizing large and / or blade-shaped intermetallic compounds. For example, AA6111 and AA6451 alloys may have relatively large intermetallic compounds when cast, which can be significantly improved by flash homogenization as disclosed herein. However, AA5754 alloy may not produce needle-shaped or blade-shaped intermetallic compounds, so AA5754 and similar alloys can omit flash homogenization. In some cases, it can be determined based on the ratio of iron to silicon when to use flash homogenization and when not to use flash homogenization, where alloys with higher silicon content (e.g., a silicon to iron ratio of 1:5 or more) can benefit from flash homogenization. In some cases, alloys with lower silicon content (e.g., a silicon to iron ratio of 1:5 or less) can be ideally cast at lower temperatures (e.g., at or about 500°C-520°C) without flash homogenization or with flash homogenization.

[0156] In some cases, flash homogenization can be performed at lower temperatures for certain alloys. For example, 7xxx series alloys can be successfully flash homogenized at temperatures at or about 350°C-480°C.

[0157] In optional block 2706, the extrudable metal article may be cooled before being extruded through a die at a hot extrusion or warm extrusion temperature. Extrusion at a hot extrusion or warm extrusion temperature may be a hot process or a warm process. In some cases, particularly where it is desired to control the precipitation of chromium, it may be beneficial to cool the extrudable metal article before hot extrusion or warm extrusion. The cooling at block 2706 may include cooling the extrudable metal article to a temperature at or about 350° C.-450° C., although other temperatures may also be used.

[0158] At box 2708, the extrudable metal article can be hot extruded or warm extruded at a diameter reduction (e.g., cross-sectional reduction) of at least about 30% and less than about 80%. In some cases, the diameter reduction can be at least about 50%, 55%, 60%, 65%, 70%, or 75%. In some cases, the hot extrusion or warm extrusion at box 2708 can optionally include quenching the metal article during extrusion (e.g., in a die), but this is not necessarily the case. In some cases, the hot extrusion or warm extrusion at box 2708 is performed while the metal article is maintained at or above a temperature of 500° C., 505° C., 510° C., 515° C., 520° C., or 525° C.

[0159] At block 2710, the extruded metal article (e.g., the extrudable metal article after extrusion) can be quenched after hot extrusion or warm extrusion. The quenching at block 2710 can include cooling the extruded metal article at a high rate (e.g., 200°C / second), although other rates can also be used. The quenching at block 2710 can reduce the temperature of the extruded metal article to at or about 50°C-400°C, such as 50°C-300°C, although other temperatures can also be used.

[0160] At block 2712, the extruded metal product may be coiled or otherwise stored. The extruded metal product may be in a final gauge and tempered state, in a final gauge, or in an intermediate gauge. If in a final gauge and tempered state or in a final gauge, the extruded metal product may be delivered to a customer for further use in its intended use. If in an intermediate gauge, the extruded metal product may be reheated, further extruded (e.g., cold extruded or hot extruded), heat treated, or otherwise processed into a final product for delivery to a customer.

[0161] At optional block 2714, the extruded metal article may be reheated to further improve metallurgical properties as described herein with respect to hot strips, including as described in the examples below. BRIEF DESCRIPTION OF THE DRAWINGS

[0162] The description refers to the following drawings, in which the same reference numerals are used in different drawings to indicate the same or similar components.

[0163] Figure 1is a schematic diagram depicting a decoupled metal casting and rolling system according to certain aspects of the present disclosure.

[0164] Figure 2 is a timing diagram for producing various coils using a decoupled metal casting and rolling system according to certain aspects of the present disclosure.

[0165] Figure 3 is a schematic diagram depicting a decoupled continuous casting system according to certain aspects of the present disclosure.

[0166] Figure 4 is a schematic diagram depicting an intermediate coil vertical storage system according to certain aspects of the present disclosure.

[0167] Figure 5 is a schematic diagram depicting an intermediate coil elevation storage system according to certain aspects of the present disclosure.

[0168] Figure 6 is a schematic diagram depicting a hot rolling system according to certain aspects of the present disclosure.

[0169] Figure 7 is a combined schematic diagram and graph depicting a hot rolling system and associated temperature profiles of a metal strip rolled thereon in accordance with certain aspects of the present disclosure.

[0170] Figure 8 is a combined schematic diagram and graph depicting a hot rolling system with intentionally undercooled rolling stands and associated temperature profiles for a metal strip rolled thereon, in accordance with certain aspects of the present disclosure.

[0171] Fig. 9 is a combined flow chart and schematic diagram depicting a process of casting and rolling a metal strip associated with a first variation of a decoupling system and a second variation of a decoupling system in accordance with certain aspects of the present disclosure.

[0172] Fig.10 is a flow chart depicting a process for casting and rolling metal strip according to certain aspects of the present disclosure.

[0173] Fig.11 is a graph depicting the temperature profile of a metal strip cast without post-casting quenching and stored at an elevated temperature prior to rolling, according to certain aspects of the present disclosure.

[0174] Fig.12 is a graph depicting a temperature profile of a metal strip cast without post-casting quenching and preheated prior to rolling in accordance with certain aspects of the present disclosure.

[0175] Fig.13 is a graph depicting a temperature profile of a metal strip cast with a post-casting quench and stored at an elevated temperature prior to rolling, according to certain aspects of the present disclosure.

[0176] Fig.14 is a graph depicting a temperature profile of a metal strip cast with a post-casting quench and preheated prior to rolling, according to certain aspects of the present disclosure.

[0177] Fig.15 is a set of magnified images depicting intermetallic compounds in aluminum alloy AA6014 for standard DC cast metal bar compared to metal bar cast using a decoupled casting and rolling system according to certain aspects of the present disclosure.

[0178] Fig.16 is a set of scanning transmission electron micrographs depicting dispersion in a 6xxx series aluminum alloy metal bar reheated at 550°C for one hour compared to a metal bar cast without a post-casting quench and a metal bar cast with a post-casting quench according to certain aspects of the present disclosure.

[0179] Fig.17 is a graph comparing yield strength and three-point bend test results for 7xxx series metal bars produced using conventional direct cooling techniques and using decoupled continuous casting and rolling in accordance with certain aspects of the present disclosure.

[0180] Fig.18 is a graph comparing yield strength and solution heat treatment soaking time results for 6xxx series metal bars produced using conventional direct cooling techniques and using decoupled continuous casting and rolling in accordance with certain aspects of the present disclosure.

[0181] Fig.19 is a set of scanning transmission electron micrographs depicting dispersion in an AA6111 aluminum alloy metal bar reheated at 550° C. for eight hours compared to a metal bar cast without a post-casting quench and a metal bar cast with a post-casting quench according to certain aspects of the present disclosure.

[0182] Fig. 20 is a graph depicting the precipitation of Mg2Si during hot rolling and quenching of an aluminum metal strip according to certain aspects of the present disclosure.

[0183] Fig.21 is a combined schematic diagram and graph depicting a hot rolling system and associated temperature profiles of a metal strip rolled thereon in accordance with certain aspects of the present disclosure.

[0184] Fig. 22 is a schematic diagram depicting a tropical continuous casting system according to certain aspects of the present disclosure.

[0185] Fig.23 is a graph depicting the precipitation of Mg2Si during hot rolling and quenching of an aluminum metal strip according to certain aspects of the present disclosure.

[0186] Fig.24 is a flow chart depicting a process for casting hot metal strip according to certain aspects of the present disclosure.

[0187] Fig.25 is a schematic diagram depicting a tropical continuous casting system according to certain aspects of the present disclosure.

[0188] Fig.26 is a schematic diagram depicting a continuous casting system according to certain aspects of the present disclosure.

[0189] Fig. 27 is a flow chart depicting a process for casting an extrudable metal product according to certain aspects of the present disclosure.

[0190] Fig.28 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0191] Fig.29 is a set of scanning electron microscope (SEM) micrographs showing the Fe component particles in AA6111 after processing according to the method described in this article.

[0192] Fig.30 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0193] Fig.31 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0194] Fig.32 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0195] Fig.33 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0196] Fig.34 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2) is a graphic representation of the log-normal number density distribution of iron (Fe) component particles.

[0197] Fig.35 is a photomicrograph showing the microstructure of an AA6014 aluminum alloy that was continuously cast into a slab having a gauge thickness of 19 mm, cooled and stored, preheated and hot rolled to a thickness of 11 mm, and further hot rolled to a thickness of 6 mm, referred to as "R1."

[0198] Fig.36 is a photomicrograph showing the microstructure of an AA6014 aluminum alloy that was continuously cast into a slab having a gauge thickness of 10 mm, cooled and stored, preheated and hot rolled to a thickness of 5.5 mm, designated "R2."

[0199] Fig.37 is a photomicrograph showing the microstructure of an AA6014 aluminum alloy that was continuously cast into a slab having a gauge thickness of 19 mm, cooled and stored, cold rolled to a thickness of 11 mm, preheated and hot rolled to a thickness of 6 mm, referred to as "R3."

[0200] Fig.38 is a graphical representation showing the effect of preheating on the formability of AA6014 aluminum alloy.

[0201] Fig.39 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm section of AA6111 metal.

[0202] Fig.40 It is a description of the Fig.39 A graphical representation of the equivalent circular diameter (ECD) of Fe constituent particles in the metal sheet shown and described.

[0203] Fig.41 It is a description of the Fig.39 Graphical representation of the aspect ratio of the Fe component particles in the metal sheet shown and described.

[0204] Fig.42 It is a description of the Fig.39 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0205] Fig.43 It is a description of the Fig.39 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0206] Fig.44 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm section of AA6111 metal.

[0207] Fig.45 It is a description of the Fig.44 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0208] Fig.46 It is a description of the Fig.44 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0209] Fig.47 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm section of AA6111 metal.

[0210] Fig.48 It is a description of the Fig.47 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0211] Fig.49 It is a description of the Fig.47 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0212] Fig.50 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 3.7-6 mm gauge ribbon.

[0213] Fig.51 It is a description of the Fig.50 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0214] Fig.52 It is a description of the Fig.50 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0215] Fig.53 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 2.0 mm gauge strips.

[0216] Fig.54 It is a description of the Fig.53 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0217] Fig.55 It is a description of the Fig.53Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0218] Fig.56 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 2.0 mm gauge strips.

[0219] Fig.57 It is a description of the Fig.56 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0220] Fig.58 It is a description of the Fig.56 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0221] Fig.59 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 3.7-6 mm gauge ribbon.

[0222] Fig.60 It is a description of the Fig.59 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0223] Fig.61 It is a description of the Fig.59 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0224] Fig.62 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 2.0 mm gauge strip.

[0225] Fig.63 It is a description of the Fig.62 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0226] Fig.64 It is a description of the Fig.62 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0227] Fig.65is a set of scanning electron microscope (SEM) and optical micrographs depicting Mg2Si melting and voids in a cross section of AA6451 metal that has been cast and cold rolled to obtain 2.0 mm gauge strip.

[0228] Fig.66 is a set of Scanning Electron Microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 2.0 mm gauge strip.

[0229] Fig.67 It is a description of the Fig.66 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0230] Fig.68 It is a description of the Fig.66 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0231] Fig.69 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a cross section of AA5754 metal.

[0232] Fig.70 It is a description of the Fig.69 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0233] Fig.71 It is a description of the Fig.69 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described. DETAILED DESCRIPTION

[0234] Examples

[0235] The following examples will be used to further illustrate the present invention, however, do not constitute any limitation thereof. On the contrary, it should be clearly understood that various embodiments, modifications and equivalents thereof may be resorted to without departing from the spirit of the present invention, which may themselves suggest themselves to those of ordinary skill in the art after reading the description herein.

[0236] Various alloys were tested using certain aspects and features of the present disclosure. Aluminum alloys are described according to their elemental composition as a weight percent (wt%) of the total alloy weight. In certain examples of each alloy, the remainder is aluminum, with a maximum wt% of the sum of impurities of 0.15%. Table 1 depicts several such alloys, including approximate solidus and solvus temperatures:

[0237] Table 1: Examples of common 5xxx, 6xxx, and 7xxx alloys

[0238]

[0239] Although Table 1 depicts several examples of common 5xxx, 6xxx, and 7xxx series alloys, other 5xxx, 6xxx, and 7xxx series alloys may exist, with constituents (e.g., alloying elements) present in varying weight percentages, with the remainder comprising aluminum and optionally trace amounts (e.g., at or less than 0.15%) of impurities. Incidental elements, such as grain refiners and deoxidizers, or other additives may be present.

[0240] Alloys AA6111 and AA6451 were produced according to the method described herein. Alloys AA6111 and AA6451 were continuously cast into slabs with a specification of 11 mm. Alloy AA6111 was further subjected to a flash homogenization procedure at different temperatures and for different durations, as shown in Table 2:

[0241] Table 2: Flash homogenization temperature and time

[0242] sample Temperature(℃) Time (minutes) Quenching A N / A N / A N / A B 570 5 N / A C 570 5 N / A D 570 5 Water quenching to 350℃ E 400 1 N / A F 380 0 N / A

[0243] Fig.28 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2). Sample A is a graph of the log-normal number density distribution of iron (Fe) component particles of the alloy. Sample A is a cast AA6111 alloy that has not been subjected to the disclosed flash homogenization procedure or hot rolling. Sample B is a continuously cast AA611111mm slab that has been subjected to the disclosed flash homogenization without any further hot rolling. Sample C is a continuously cast AA611111mm slab that has been subjected to the disclosed flash homogenization and hot rolled to a thickness reduction of 50% (i.e., 6.5mm specification). Sample D is a continuously cast AA611111mm slab that has been subjected to the disclosed flash homogenization, hydrothermally quenched to a temperature of 350°C with room temperature and hot rolled to a thickness reduction of 50% (i.e., 6.5mm specification). Sample E is a continuously cast AA611111mm slab that has been subjected to optional flash homogenization (see Table 2) and hot rolled to a 50% reduction (i.e., 6.5mm specification). Sample F is a continuously cast AA611111 mm slab subjected to optional flash homogenization (see Table 2) and hot rolled to 50% reduction (i.e., 6.5 mm gauge). Sample A (as-cast AA6111 slab) shows a broad peak, indicating a broad particle size distribution and a lack of refinement of the Fe component. Sample C (AA6111 cast into 11 mm slabs, subjected to the disclosed flash homogenization and hot rolled to 50% reduction) shows a narrow particle size distribution, indicating refinement of the Fe component particles. Samples D and E (subjected to optional flash homogenization at lower temperatures, 400°C for Sample D and 380°C for Sample E) show a broad particle size distribution, indicating a lower degree of refinement of the Fe component particles.

[0244] Fig.29 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in AA6111 alloy after processing according to the method described herein. Fig.29 Figures A, B, C, D, E and F are respectively Fig.28 Figure 2 is related to Samples A, B, C, D, E and F of Figure 2. Figure A shows the large needle-shaped Fe component particles 2401 in Sample A (see Table 2). Figure B shows the refinement (i.e., crushing) of the Fe component particles after the AA6111 alloy was subjected to the disclosed flash homogenization without being subjected to hot rolling (Sample B, Table 2). Figure C shows the further refinement of the Fe component particles in Sample C, where the 11 mm gauge slab of the AA6111 alloy continuously cast was subjected to the disclosed flash homogenization and further subjected to hot rolling to a thickness reduction of 50%. Figure C shows more refinement, such as by Fig.28, as evidenced by the lognormal distribution fit of Sample C. Graph D shows the refinement of the Fe component particles in Sample D, similar to the refinement seen in Sample C, where the AA6111 alloy continuously cast 11 mm gauge slab was subjected to the disclosed flash homogenization and further subjected to water quenching to 350°C, followed by hot rolling to a 50% reduction in thickness. Graph E illustrates the lack of refinement of the Fe component particles and undissolved magnesium silicide (Mg2Si) particles present in Sample E, where the AA6111 alloy continuously cast 11 mm slab was subjected to flash homogenization at 400°C for 1 minute, and then hot rolled to a 50% reduction in thickness. Graph F illustrates the lack of refinement of the Fe component particles and undissolved magnesium silicide (Mg2Si) particles present in Sample F, where the AA6111 alloy continuously cast 11 mm slab was subjected to flash homogenization at 380°C without residence time, and then hot rolled to a 50% reduction in thickness.

[0245] Fig.30 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ) is a graphical representation of the log-normal number density distribution of iron (Fe) component particles. Sample C, Sample D and Sample E (see Table 2) were further subjected to additional homogenization after hot rolling to 50% thickness reduction. Table 3 summarizes the additional homogenization procedure:

[0246] Table 3: Additional homogenization parameters

[0247]

[0248] All samples subjected to the disclosed flash homogenization and hot rolling to 50% reduction) followed by additional homogenization at various temperatures showed narrow particle size distributions, indicating refinement of the Fe component particles. High temperature flash homogenization (e.g., 570°C, Sample C and Sample D (Tests G, H, V, and W)) continued to exhibit more Fe component particle refinement than low temperature flash homogenization (e.g., 400°C and below, Sample E (Tests I, J, X, and Y)).

[0249] Fig.31 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ). For each of these flash homogenization tests, an 11 mm metal strip was hot rolled to 2 mm. For some cases, the initial hot rolling (e.g., "Q1" reduction) was performed at a 50% thickness reduction, followed by a 68% final thickness reduction, resulting in a 2 mm strip. In some cases, the initial hot rolling was performed at a 70% thickness reduction, followed by a 40% final thickness reduction, resulting in a 2 mm strip. Table 4 summarizes the additional homogenization and hot rolling parameters:

[0250] Table 4: Additional homogenization and hot rolling parameters

[0251]

[0252] All samples subjected to the disclosed flash homogenization and initially hot rolled to at least 50% reduction, then subjected to additional homogenization and hot rolled to the desired gauge (e.g., 2 mm) exhibited narrow particle size distributions, indicating refinement of the Fe component particles. Samples subjected to the disclosed flash homogenization (e.g., 570°C for 5 minutes, Sample C and Sample D, Tests G, H, Z, AA, AB, and AC) exhibited narrower distributions of fine Fe component particles than samples subjected to lower temperature flash homogenization (e.g., 400°C, Sample E, Tests I, J, AD, and AE), indicating that further homogenization is not required when the disclosed high temperature flash homogenization is used.

[0253] Fig.32 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ). Sample F (see Table 2) was further subjected to additional homogenization and further hot rolled to a 70% total thickness reduction (i.e., compared to the 11 mm slab continuously cast from the as-cast AA6111 alloy (Sample A, see Table 2), Sample F was hot rolled to an additional 20% thickness reduction. The as-cast AA6111 alloy was not subjected to the disclosed flash homogenization. The as-cast AA6111 alloy was subjected to additional homogenization and hot rolling similar to Sample F, with the parameters summarized in Table 5:

[0254] Table 5: Low temperature flash homogenization vs. no flash homogenization

[0255]

[0256] All samples subjected to the disclosed flash homogenization and then hot rolled to at least 50% reduction, followed by additional homogenization and hot rolled to the desired gauge (e.g., 2 mm) showed a narrow particle size distribution, indicating refinement of the Fe component particles. Samples not subjected to the disclosed flash homogenization showed less refinement of the Fe component particles.

[0257] Alloy AA6451 was further subjected to a flash homogenization procedure at different temperatures and for different durations, as shown in Table 6:

[0258] Table 6: Flash homogenization temperature and time

[0259]

[0260]

[0261] Fig.33is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ). Sample AAA (indicated by the solid blue line) is an as-cast AA6451 that has not been subjected to the disclosed flash homogenization procedure or hot rolling. Sample CCC (indicated by the small green dashed line) is a continuously cast AA645 111 mm slab that has been subjected to the disclosed flash homogenization and hot rolled to a thickness reduction of 50% (i.e., 6.5 mm specification). Sample DDD (indicated by the single-dash purple line) is a continuously cast AA645 111 mm slab that has been subjected to the disclosed flash homogenization, hydrothermally quenched to a temperature of 350°C with room temperature, and hot rolled to a thickness reduction of 50% (i.e., 6.5 mm specification). Sample EEE (indicated by the double-dash black line) is a continuously cast AA645 111 mm slab that has been subjected to optional flash homogenization (see Table 2) and hot rolled to a 50% reduction (i.e., 6.5 mm specification). Sample FFF (represented by the orange solid line) is a continuously cast AA645 111 mm slab that is subjected to optional flash homogenization (see Table 2) and hot rolled to 50% reduction (i.e., 6.5 mm gauge). Sample AAA (as-cast AA6451 slab) shows a broad peak, indicating a broad particle size distribution and a lack of refinement of the Fe component. Sample CCC (AA6451 cast into 11 mm slabs, subjected to the disclosed flash homogenization and hot rolled to 50% reduction) shows a narrow particle size distribution, indicating refinement of the Fe component particles. Samples DDD and EEE (subjected to optional flash homogenization at lower temperatures, sample DDD is 400°C, and sample EEE is 380°C) show a broad particle size distribution, indicating a lower degree of refinement of the Fe component particles.

[0262] Fig.34 is a graph showing the particle size of the alloy produced according to the method described herein, per square micrometer (μm 2 ). Sample FFF (see Table 2) was further subjected to additional homogenization and further hot rolled to 70% total thickness reduction (i.e., Sample FFF was initially hot rolled to an additional 20% thickness reduction) and compared to a 11 mm slab continuously cast from an as-cast AA6451 alloy (Sample AAA, see Table 2). The as-cast AA6451 alloy was not subjected to the disclosed flash homogenization. The as-cast AA6451 alloy was subjected to additional homogenization and hot rolling similar to Sample FFF, with the parameters summarized in Table 7:

[0263] Table 7: Low temperature flash homogenization vs. no flash homogenization

[0264]

[0265] All samples (except UU) subjected to the disclosed flash homogenization and hot rolling to at least 50% thickness reduction, followed by additional homogenization and hot rolling to the desired gauge (e.g., 2 mm) showed narrow particle size distributions, indicating refinement of the Fe component particles. Samples not subjected to the disclosed flash homogenization showed less refinement of the Fe component particles. Sample UU was subjected to the disclosed flash homogenization (e.g., 570° C. for 5 minutes) and immediately hot rolled to 70% thickness reduction, and exhibited excellent refinement of the Fe component particles after further homogenization and an additional 40% hot rolling.

[0266] Fig.35 , Fig.36 and Fig.37 is a micrograph showing the microstructure of AA6014 aluminum alloy. Fig.35 AA6014 aluminum alloy is shown, which is continuously cast into a slab with a gauge thickness of 19 mm, cooled and stored, preheated and hot rolled to a thickness of 11 mm, and further hot rolled to a thickness of 6 mm, referred to as "R1". Preheating is performed by heating the cooled slab under two conditions: (i) heating to 550°C in 1 minute or (ii) heating to 420°C in 30 seconds. The rolling direction is indicated by arrow 3001. Fig.35 The effects on grain size and degree of recrystallization after hot rolling are illustrated. Fig.36 AA6014 aluminum alloy is shown which was continuously cast into a slab having a gauge thickness of 10 mm, cooled and stored, preheated and hot rolled to a thickness of 5.5 mm, referred to as "R2". Preheating was performed by heating the cooled slab under two conditions: (i) to 550°C in 1 minute or (ii) to 420°C in 30 seconds. The rolling direction is indicated by arrow 3101. Fig.36 The effects on grain size and degree of recrystallization after hot rolling are illustrated. Fig.37 AA6014 aluminum alloy is shown, which is continuously cast into a slab having a gauge thickness of 19 mm, cooled and stored, cold rolled to a thickness of 11 mm, preheated, and hot rolled to a thickness of 6 mm, referred to as "R3". Preheating is performed by heating the cooled slab under two conditions: (i) heating to 550°C in 1 minute or (ii) heating to 420°C in 30 seconds. The rolling direction is indicated by arrow 3201. Fig.37 The effects on grain size and degree of recrystallization after hot rolling are illustrated.

[0267] Fig.38 1 is a graph showing the effect of preheating on the formability of AA6014 aluminum alloy. Figure 30-32The heating and rolling procedures described above are referred to as "R1, R2 and R3", respectively. The AA6014 aluminum alloy was preheated at a temperature of 550°C for 1 minute (referred to as "HO1", the left histogram in each group), resulting in an aluminum alloy with excellent formability characteristics, which is indicated by an inner bend angle of less than 20°. The AA6014 aluminum alloy was preheated at a temperature of 420°C for 1 minute (referred to as "HO2", the right histogram in each group), resulting in an aluminum alloy with extremely low formability, which is indicated by a relatively high inner bend angle (e.g., exceeding 20°). All samples were water quenched (referred to as "WQ") after hot rolling and pre-strained by 10% before bending testing.

[0268] Fig.39 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm gauge section of AA6111 metal. Figures α1, α2, α3, α5 and α6 depict the continuous casting apparatus used, such as Fig. 22 Figure α1 shows the as-cast metal, with large needle-shaped Fe component particles. Figure α4 shows the equivalent metal sheet from the direct cooling casting system, with very large Fe component particles. Figures α2, α3, α5 and α6 are all cast in a soaking furnace (e.g., Fig. 22 The steel was heated in a soaking furnace 2217 for 2 minutes. A small Fe component is seen in each of Figures α2, α3, α5, and α6, with the smallest Fe component in Figure α6. In addition, spheroidization is hardly seen in any of the figures except Figure α6.

[0269] Fig.40 It is a description of the Fig.39 A graphical representation of the equivalent circular diameter (ECD) of Fe constituent particles in the metal sheet shown and described. Fig.40 The graphical representation of is based on a log-normal probability density function. As used herein, the equivalent circular diameter can be calculated by measuring the area of ​​a particle (e.g., a Fe component particle) and determining the diameter of a circle that would have the same total area. In other words,

[0270] Fig.41 It is a description of the Fig.39 Graphical representation of the aspect ratio of the Fe component particles in the metal sheet shown and described. Fig.41 The graphical representation of is based on a log-normal probability density function. The aspect ratio can be determined by dividing the length of the particle in a first direction by the width of the particle in a perpendicular direction. The aspect ratio can indicate the amount of spheroidization that the particle has experienced.

[0271] Fig.42 It is a description of the Fig.39A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0272] Fig.43 It is a description of the Fig.39 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0273] Figure 39-43 It is shown that a smaller Fe content can be obtained by flash homogenization of a continuously cast metal product, especially at a temperature at or about 570°C. In addition, the higher peak metal temperature during flash homogenization appears to indicate finer particles. Finally, significant spheroidization (e.g., smaller aspect ratio) is evident when a peak metal temperature at or about 570°C is reached, with little spheroidization at lower temperatures.

[0274] Fig.44 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm gauge section of AA6111 metal. Figures α7, α8, α9 and α11 depict the use of a continuous casting device, such as Fig. 22 Figure α7 shows the as-cast metal, with large needle-shaped Fe component particles. Figure α10 shows an equivalent metal sheet from a direct cooling casting system, with very large Fe component particles. Figure α11 shows an equivalent metal sheet from a direct cooling casting system after being homogenized for 2 minutes at a peak metal temperature of 570°C. Figures α8, α9 and α12 are all cast in a soaking furnace (e.g., Fig. 22 The ingot was heated to a peak metal temperature of 570°C in a soaking furnace 2217 for periods of 1 minute, 2 minutes, and 3 minutes, respectively. A smaller Fe component is seen in each of Figures α8, α9, and α11, with the smallest in Figure α11. Longer soaking times show more spheroidization, with the desired spheroidization being achieved at 2 and 3 minutes. A 2 minute soaking for the direct cooled ingot does not show any noticeable microstructural changes.

[0275] Fig.45 It is a description of the Fig.44 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0276] Fig.46 It is a description of the Fig.44 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0277] Fig.45 and 46It has been shown that a smaller Fe content can be obtained by flash homogenization of a continuously cast metal product, particularly at a temperature at or about 570°C with a soaking time of at least or about 1 or 2 minutes.

[0278] Fig.47 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a 11.3 mm gauge section of AA6111 metal. Figure α13 depicts the use of a continuous casting apparatus, such as Fig. 22 The metal cast by the belt caster 2208 of the tropical continuous casting system 2200 is flash homogenized at 565° C. for 5 minutes (e.g., using Fig. 22 Figures α14, α15, α16, α17, α18 and α19 depict the use of a continuous casting device, such as Fig. 22 The metal cast by the belt caster 2208 of the tropical continuous casting system 2200 is flash homogenized at 565° C. for 5 minutes (e.g., using Fig. 22 The hot rolling is then performed (for example, using a soaking furnace 2217). Fig. 22 Rolling stand 2284) with thickness reductions of 10%, 20%, 30%, 40%, 50%, 60% and 70%. Flash homogenization followed by higher heat reduction shows a smaller Fe content, although there seems to be a plateau after which higher thickness reductions are attributed to smaller benefits.

[0279] Fig.48 It is a description of the Fig.47 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0280] Fig.49 It is a description of the Fig.47 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0281] Fig.48 and 49 It is shown that by flash homogenizing the continuously cast metal product and then hot rolling, a smaller Fe component can be obtained, especially at or about 40%-70% thickness reduction. Higher thermal reductions show more Fe component particle fragmentation, although 50%-70% thermal reduction appears to provide relatively similar amounts of fragmentation.

[0282] Fig.50is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 3.7-6 mm gauge strip. Figure α20 depicts direct cooled cast metal which has been re-rolled to about 3.7-6 mm gauge. Figures α21, α22, α23, α24, α25 and α26 depict continuous casting apparatus such as Fig. 22 The belt caster 2208 of the tropical continuous casting system 2200 is cast and subjected to a certain amount of hot rolling (for example, using Fig. 22 Figures α21, α22 and α23 were not flash homogenized, while Figures α24, α25 and α26 were flash homogenized. Figures α21 and α24 experienced a 45% thickness reduction, Figures α22 and α25 experienced a 45% thickness reduction and reheated to 530°C for 2 hours, and Figures α23 and α26 experienced a 60% thickness reduction. Smaller Fe component particles can be seen after flash homogenization followed by a higher heat reduction. In addition, reheating after hot rolling seems to promote spheroidization.

[0283] Fig.51 It is a description of the Fig.50 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0284] Fig.52 It is a description of the Fig.50 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0285] Fig.51 and 52 It was shown that by flash homogenizing the continuously cast metal product followed by hot rolling, a smaller Fe content can be obtained, especially compared to hot rolling without flash homogenization. In addition, reheating after hot rolling appears to improve spheroidization.

[0286] Fig.53 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 2.0 mm gauge strip. Figure α27 depicts direct cooling cast metal which has been rolled to a final gauge of 2.0 mm. Figures α28, α29, α30, α31, α32, α33 and α34 depict metal which has been subjected to continuous casting apparatus, e.g. Fig. 22 The metal cast by the belt caster 2208 of the tropical continuous casting system 2200 of FIG. α31 has been continuously cast and then cold rolled to a final specification of 2.0 mm. FIG. α28, α29, α30, α32, α33 and α34 have been subjected to a certain amount of hot rolling (e.g., using Fig. 22Rolling stand 2284). Figures α28, α29 and α30 are not flash homogenized, while Figures α32, α33 and α34 are flash homogenized. Figures α28 and α32 undergo 45% thickness reduction under hot rolling and are then cold rolled to a final specification of 2.0 mm. Figures α29 and α33 undergo 45% thickness reduction under hot rolling, are then heated to 530°C and maintained for 2 hours, and are then warm rolled to a final specification of 2.0 mm. Figures α30 and α34 undergo 60% thickness reduction under hot rolling and are then cold rolled to a final specification of 2.0 mm.

[0287] Fig.54 It is a description of the Fig.53 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0288] Fig.55 It is a description of the Fig.53 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0289] Fig.54 and 55 It was shown that a smaller Fe component can be obtained by flash homogenizing a continuously cast metal product followed by hot rolling and reheating, especially when compared to hot rolling and cold rolling alone. Reheating after hot rolling showed improved spheroidization of the Fe component particles. Although cold rolling after continuous casting did show some degree of Fe component particle fragmentation, it did not achieve the desired spheroidization.

[0290] In addition, the bending test was performed according to the German Association of the Automotive Industry (VDA) specification 238-100 for performing the bending test and the specification 232-200 for standardizing the test to 2.0 mm. Fig.53 The samples from Figures α27, α28, α29, α30, α31, α32, α33 and α34 achieved α (outer) bending angles of 80°, 79°, 75°, 67°, 66°, 96°, 102° and 95°, respectively.

[0291] Fig.56 is a set of scanning electron microscope (SEM) micrographs showing Fe component particles in a cross section of AA6111 metal after undergoing various processing routes to obtain 2.0 mm gauge strip. Figures α35, α36, α37 and α38 depict continuous casting equipment such as Fig. 22 The belt caster 2208 of the tropical continuous casting system 2200 is cast, flash homogenized (for example, using Fig. 22 soaking furnace 2217) and hot rolled at 45% thickness reduction (e.g., using Fig. 22Figures α35, α36 and α37 are then reheated at 530°C for 2 hours, while Figure α38 is immediately cold rolled to a final gauge of 2.0 mm. After reheating, Figure α35 is warm rolled to a final gauge of 2.0 mm. After reheating, Figure α36 is again hot rolled at a 50% thickness reduction, then quenched and cold rolled to a final gauge of 2.0 mm. After reheating, Figure α37 is quenched and cold rolled to a final gauge of 2.0 mm.

[0292] Fig.57 It is a description of the Fig.56 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0293] Fig.58 It is a description of the Fig.56 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0294] Fig.57 and 58 It was shown that a smaller Fe component can be obtained by flash homogenizing a continuously cast metal product followed by hot rolling and reheating, especially when compared to hot rolling and cold rolling alone. Reheating after hot rolling showed improved spheroidization of the Fe component particles. Although cold rolling after continuous casting did show some degree of Fe component particle fragmentation, it did not achieve the desired spheroidization.

[0295] In addition, the bending test was performed according to the German Association of the Automotive Industry (VDA) specification 238-100 for performing the bending test and the specification 232-200 for standardizing the test to 2.0 mm. Fig.56 The samples from Figures α35, α36, α37 and α38 achieved α (outer) bending angles of 96°, 95°, 104° and 93° respectively.

[0296] Fig.59 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 3.7-6 mm gauge strip. Figure β1 depicts the direct cooling cast metal, which has been re-rolled to about 3.7-6 mm gauge. Figures β2, β3, β4, β5, β6, β7 and β8 depict the continuous casting device, such as Fig. 22 Figure β2 shows a 6 mm strip as cast. Figures β2, β3, β4, β6, β7 and β8 are subjected to a certain amount of hot rolling (e.g., using Fig. 22Rolling stand 2284). Figures β2, β3 and β4 were not flash homogenized, while Figures β6, β7 and β8 were flash homogenized. Figures β2 and β6 experienced a 45% thickness reduction without further heating. Figures β3 and β6 experienced a 45% thickness reduction and were reheated to 530°C and maintained for 2 hours. Figures β4 and β8 experienced a 60% thickness reduction without further heating. Smaller Fe component particles are visible after flash homogenization followed by a higher heat reduction. In addition, reheating after hot rolling appears to promote spheroidization. It is worth noting that the dark spots seen in Figure β3 were determined to be abnormal based on further testing.

[0297] Fig.60 It is a description of the Fig.59 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0298] Fig.61 It is a description of the Fig.59 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0299] Fig.60 and 61 It was shown that a smaller Fe content can be obtained by flash homogenizing the continuously cast metal product and then hot rolling, especially when hot rolling is performed without flash homogenization. In addition, reheating after hot rolling seems to improve spheroidization.

[0300] Fig.62 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 2.0 mm gauge strip. Figure β9 depicts the direct cooling cast metal which has been rolled to a final gauge of 2.0 mm. Figures β10, β11, β12, β13, β14, β15 and β16 depict the metal which has been subjected to continuous casting apparatus, e.g. Fig. 22 Figure β13 has been continuously cast and then cold rolled to a final gauge of 2.0 mm. Figures β10, β11, β12, β14, β15, and β16 have been subjected to a certain amount of hot rolling (e.g., using Fig. 22Figures β10, β11 and β12 were not flash homogenized, while Figures β14, β15 and β16 were flash homogenized. Figures β10 and β14 were subjected to 45% thickness reduction under hot rolling and then cold rolled to a final gauge of 2.0 mm. Figures β11 and β15 were subjected to 45% thickness reduction under hot rolling, then heated to at or about 530°C for 2 hours and then warm rolled to a final gauge of 2.0 mm. Figures β12 and β16 were subjected to 60% thickness reduction under hot rolling and then cold rolled to a final gauge of 2.0 mm.

[0301] Fig.63 It is a description of the Fig.62 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0302] Fig.64 It is a description of the Fig.62 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0303] Fig.63 and 64 It was shown that a smaller Fe component can be obtained by flash homogenizing a continuously cast metal product followed by hot rolling and reheating, especially when compared to hot rolling and cold rolling alone. Reheating after hot rolling showed improved spheroidization of the Fe component particles. Although cold rolling after continuous casting did show some degree of Fe component particle fragmentation, it did not achieve the desired spheroidization.

[0304] In addition, the bending test was performed according to the German Association of the Automotive Industry (VDA) specification 238-100 for performing the bending test and the specification 232-200 for standardizing the test to 2.0 mm. Fig.62 The samples from Figures β9, β10, β11, β12, β13, β14, β15 and β16 achieved α (outer) bending angles of 70°, 67°, 88°, 75°, 65°, 75°, 80° and 81°, respectively.

[0305] Fig.65is a set of scanning electron microscope (SEM) micrographs and optical micrographs depicting Mg2Si melting and voids in a cross section of AA6451 metal that has been cast and cold rolled to obtain 2.0 mm gauge strips. Figures β17, β18, β21 and β22 are SEM micrographs, while Figures β19, β20, β23 and β24 are optical micrographs. Each sample has been continuously cast and then cold rolled without undergoing the process of the present disclosure. Figures β17, β18, β19 and β20 are based on metal in the F temper state (e.g., without solution heat treatment), while Figures β21, β22, β23 and β24 are based on metal in the T4 temper state (e.g., with additional solution heat treatment). The results show that the solution heat treatment of the cold rolled sample shows many voids, which may be at least partially attributed to the presence of rough cast Mg2Si in the F temper state. Therefore, it is apparent that improvements in the intermetallic microstructure can be beneficial for obtaining the desired T4 temper product.

[0306] Fig.66 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA6451 metal after undergoing various processing routes to obtain 2.0 mm gauge strip. Figures β25, β26, β27 and β28 depict the continuous casting apparatus used, e.g. Fig. 22 The strip caster 2208 of the tropical continuous casting system 2200 is cast and then subjected to 45% thickness reduction hot rolling (for example, using Fig. 22 Figure β25 is then reheated at 530°C for 2 hours and then warm rolled to final gauge. Figure β26 is then reheated at 530°C for 2 hours and then hot rolled for an additional 50% thickness reduction, then water quenched and then cold rolled to final gauge. Figure β27 is then reheated at 530°C for 2 hours and then water quenched and then cold rolled to final gauge. Figure β28 is then cold rolled. The greatest improvement in Fe content spheroidization is found in the final gauge when the metal strip is flash homogenized, hot rolled or warm rolled, then preheated, then water quenched and then cold rolled to final gauge.

[0307] Fig.67 It is a description of the Fig.66 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0308] Fig.68 It is a description of the Fig.66 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0309] picture Fig.67 and 68It was shown that a lower Fe content can be achieved by flash homogenizing a continuously cast metal product followed by hot rolling and reheating, especially when combined with a subsequent water quench and cold rolling to final gauge. It was determined that homogenization (e.g., reheating) can benefit spheroidization, and that quenching after homogenization can benefit particle distribution.

[0310] In addition, the bending test was performed according to the German Association of the Automotive Industry (VDA) specification 238-100 for performing the bending test and the specification 232-200 for standardizing the test to 2.0 mm. Fig.66 The samples from Figures β25, β26, β27 and β28 achieved α (outer) bending angles of 75°, 67°, 78° and 71° respectively.

[0311] Fig.69 is a set of scanning electron microscope (SEM) micrographs showing Fe constituent particles in a cross section of AA5754 metal. Figure γ4 depicts metal that has been directly cooled cast and reduced to final specifications. Figures γ1, γ2, γ3, γ5 and γ6 depict metal that has been cast using a continuous casting device, such as Fig. 22 The belt caster 2208 of the tropical continuous casting system 2200 casts and hot rolls at various thickness reductions (e.g., using Fig. 22 Figures γ1, γ2, γ5 and γ6 are not flash homogenized before hot rolling, while Figures γ3 and γ7 are flash homogenized before hot rolling. Figure γ1 is subjected to 50% hot rolling to final specifications. Figure γ2 is subjected to 70% hot rolling to final specifications. Figure γ3 is subjected to 70% hot rolling to final specifications. Figure γ5 is subjected to 50% hot rolling and then additional cold rolling to final specifications. Figure γ6 is subjected to 70% hot rolling and then additional cold rolling to final specifications. Figure γ7 is subjected to 70% hot rolling and then additional cold rolling to final specifications. It can be seen that the greatest improvement in Fe component particle crushing and / or spheroidization is found when the metal strip is continuously cast, flash homogenized, and then hot rolled.

[0312] Fig.70 It is a description of the Fig.69 A graphical representation of median and distribution data of equivalent circular diameters of Fe constituent particles in a metal sheet as shown and described.

[0313] Fig.71 It is a description of the Fig.69 Graphical representation of median and distribution data of aspect ratio of Fe constituent particles in metal sheets shown and described.

[0314] Fig.70 and 71 It was shown that by flash homogenizing a continuously cast metal product followed by hot rolling, a lower Fe content can be achieved, especially when compared to hot rolling without flash homogenization.

[0315] In addition, the bending test was performed according to the German Association of the Automotive Industry (VDA) specification 238-100 for performing the bending test and the specification 232-200 for standardizing the test to 2.0 mm. Fig.69 The samples from Figures γ5 and γ7 achieved α (outer) bending angles of 160° and 171°, respectively.

[0316] The foregoing description of the embodiments, including the illustrated embodiments, has been presented for purposes of illustration and description only and is not intended to be exhaustive or limited to the precise forms disclosed. Many modifications, adaptations, and uses thereof will be apparent to those skilled in the art.

[0317] As used below, any reference to a series of examples should be understood as a reference to each of those examples individually (eg, "Examples 1-4" should be understood as "Example 1, 2, 3, or 4").

[0318] Example 1 is a metal casting and processing system comprising: a continuous casting apparatus for casting a metal strip at a first speed; and a hot rolling mill stand operated at a second speed decoupled from the first speed.

[0319] Example 2 is the system of Example 1, further comprising: a coiling device operably coupled to the continuous casting device for coiling the metal strip into an intermediate coil; and an uncoiling device for receiving the intermediate coil and operably coupled to the hot rolling stand to provide the metal strip to the nip of the hot rolling stand.

[0320] Example 3 is the system of Example 2, further comprising a preheating device for receiving the intermediate coil.

[0321] Example 4 is the system of example 2 or 3, further comprising a storage system for storing the intermediate coil in a vertical direction.

[0322] Example 5 is the system of example 2-4, further comprising a storage system for storing the intermediate coil, wherein the storage system includes a motor for rotating the intermediate coil.

[0323] Example 6 is the system of Examples 1-5, further comprising: a heat source located downstream of the hot rolling stand; and a quenching system located immediately downstream of the heat source.

[0324] Example 7 is the system of Example 1-6, further comprising: a preheating heat source located upstream of the hot rolling stand; and a quenching system located between the preheating heat source and the hot rolling stand.

[0325] Example 8 is the system of example 1 or 6-7, further comprising an accumulator operably positioned between the continuous casting apparatus and the hot rolling stand for accommodating a difference between the first speed and the second speed.

[0326] Example 9 is the system of Example 1-8, further comprising a post-casting quenching device located immediately downstream of the continuous casting device.

[0327] Example 10 is the system of Examples 1-9, wherein the continuous casting apparatus is a belt casting apparatus.

[0328] Example 11 is a metal casting and processing system, which includes: a continuous belt casting device for casting a metal strip; a winding device associated with the continuous casting device, for winding the metal strip into an intermediate coil; and an unwinding device for receiving the intermediate coil, the unwinding device being operably coupled to at least one hot rolling stand for reducing the thickness of the metal strip to a desired thickness.

[0329] Example 12 is the system of Example 11, further comprising a preheating device for receiving the intermediate coil.

[0330] Example 13 is the system of example 11 or 12, further comprising a storage system for storing the intermediate coil in a vertical direction.

[0331] Example 14 is the system of examples 11-13, further comprising a storage system for storing the intermediate coil, wherein the storage system includes a motor for rotating the intermediate coil.

[0332] Example 15 is the system of Examples 11-14, further comprising: a heat source located downstream of the hot rolling stand; and a quenching system located immediately downstream of the heat source.

[0333] Example 16 is the system of Examples 11-15, further comprising: a preheating heat source located upstream of the hot rolling stand; and a quenching system located between the preheating heat source and the hot rolling stand.

[0334] Example 17 is the system of Examples 11-16, further comprising a post-casting quenching device located immediately downstream of the continuous casting device.

[0335] Example 17.5 is the system of Examples 11-17, wherein at least one hot rolling stand is located between the continuous strip casting apparatus and the coiling apparatus for reducing the thickness of the metal strip when the continuous strip casting apparatus is not casting the metal strip.

[0336] Example 18 is a casting and rolling method comprising: continuously casting a metal strip at a first speed; and hot rolling the metal strip at a second speed, wherein the first speed is decoupled from the second speed.

[0337] Example 19 is the method of Example 18, further comprising winding the cast metal strip into an intermediate coil, wherein hot rolling the metal strip comprises unwinding the intermediate coil.

[0338] Example 20 is the method of Example 19, further comprising preheating the intermediate coil.

[0339] Example 21 is the method of example 19 or 20, further comprising storing the intermediate coil in a vertical position.

[0340] Example 22 is the method of examples 19-21, further comprising storing the intermediate coil, wherein storing the intermediate coil comprises periodically or continuously rotating the intermediate coil.

[0341] Example 23 is the method of Examples 18-22, further comprising heat treating the metal strip after hot rolling the metal strip, wherein heat treating the metal strip comprises applying heat to the metal strip and immediately quenching the metal strip.

[0342] Example 24 is the method of Examples 18-23, further comprising reheating the metal strip prior to hot rolling the metal strip, wherein reheating the metal strip comprises heating the metal strip to a temperature above the hot rolling temperature and quenching the metal strip to the hot rolling temperature.

[0343] Example 25 is the method of examples 18 or 23-24, further comprising directing the metal strip through an accumulator, wherein the accumulator compensates for a difference between the first speed and the second speed.

[0344] Example 26 is the method of Examples 18-25, wherein continuously casting the metal strip includes passing the liquid metal through a pair of rollers to extract heat from the liquid metal and solidify the liquid metal.

[0345] Example 27 is an intermediate metal product comprising: a primary phase of solid aluminum formed by cooling liquid metal in a continuous casting apparatus with a strip thickness between 7 mm and 50 mm; and a secondary phase including alloying elements, wherein the alloying elements are supersaturated in the primary phase by rapidly cooling the newly solidified metal to a temperature below the solution temperature.

[0346] Example 28 is the metal product of Example 27, wherein the metal product is formed into the shape of a metal strip wound into an intermediate coil.

[0347] Example 30 is a metal strip derived from the intermediate metal product of Examples 27-28, wherein the metal strip comprises dispersions uniformly distributed throughout the primary phase, and wherein the average size of the dispersions is between 10 nm and 500 nm.

[0348] Example 30 is a metal casting system comprising: a continuous casting device for casting a metal strip; and at least one nozzle located near the continuous casting device for delivering a coolant to the metal strip, wherein the coolant is sufficient to quickly cool the metal strip when the metal strip leaves the continuous casting device.

[0349] Example 31 is the system of Example 30, wherein the continuous casting device is arranged to cast the metal strip at a thickness between 7 mm and 50 mm.

[0350] Example 32 is the system of example 30 or 31, wherein the at least one nozzle is arranged to rapidly cool the metal strip to a temperature at or below 100° C. within ten seconds as the metal strip exits the continuous casting apparatus.

[0351] Example 33 is the system of Examples 30-32, further comprising a reheater located downstream of the at least one nozzle for heating the metal strip to a temperature at or above the solution temperature.

[0352] Example 34 is the system of Example 33, wherein the solution temperature is about 30° C. below the solidus temperature of the metal in the metal strip. In some cases, the solution temperature is about 25° C.-35° C. below the solidus temperature of the metal in the metal strip.

[0353] Example 34.5 is the system of Example 33 or 34, wherein the solution temperature is at or above 450°C.

[0354] Example 35 is a system of Example 33 or 34, further comprising a quench device located downstream of the reheater for rapidly cooling the metal strip to a temperature below the solution temperature, wherein the quench device is located a distance from the reheater suitable for allowing the metal strip to be maintained at or above the solution temperature for a duration of two hours or less.

[0355] Example 36 is the system of Example 35, wherein the distance between the quench device and the reheater is adapted to allow the metal strip to be maintained at or above the solution temperature for a duration of one hour or less.

[0356] Example 37 is the system of Example 35, wherein the distance between the quench device and the reheater is adapted to allow the metal strip to be maintained at or above the solution temperature for a duration of five minutes or less.

[0357] Example 38 is the system of Examples 30-37, wherein the continuous casting apparatus is a belt caster.

[0358] Example 39 is the system of examples 30-38, further comprising a winding device located downstream of the at least one nozzle for winding the metal strip into an intermediate coil.

[0359] Example 40 is a method comprising: continuously casting a metal strip using a continuous casting apparatus; and rapidly quenching the metal strip when the metal strip leaves the continuous casting apparatus.

[0360] Example 41 is the method of Example 40, wherein continuously casting the metal strip includes continuously casting the metal strip at a thickness between 7 mm and 50 mm.

[0361] Example 42 is the method of Example 40 or 41, wherein rapidly quenching the metal strip comprises applying a coolant to the metal strip sufficient to cool the metal strip to a temperature at or below 100° C. within 10 seconds of the metal strip exiting the continuous casting apparatus.

[0362] Example 43 is the method of Examples 40-42, further comprising reheating the metal strip after rapidly quenching the metal strip, wherein reheating the metal strip comprises heating the metal strip to a solution temperature.

[0363] Example 44 is the method of Example 43, wherein the solution temperature is at or above 480°C.

[0364] Example 45 is the method of Example 43 or 44, further comprising quenching the metal strip after reheating the metal strip to cool the metal strip to below the solution temperature, wherein the quenching occurs after allowing the metal strip to remain at or above the solution temperature for a duration of two hours or less.

[0365] Example 46 is the method of example 45, wherein the duration is 1 hour or less.

[0366] Example 47 is the method of example 45, wherein the duration is 1 minute or less.

[0367] Example 48 is the method of Examples 40-47, wherein continuously casting the metal strip includes passing the liquid metal through a pair of rollers to extract heat from the liquid metal and solidify the liquid metal.

[0368] Example 49 is the method of Examples 40-48, further comprising winding the metal strip into an intermediate coil after rapidly quenching the metal strip.

[0369] Example 50 is the system of any of Examples 1-5 or Examples 8-10, further comprising a quenching system located immediately downstream of the hot rolling stand, wherein the hot rolling stand is positioned to receive the metal strip at a temperature above the recrystallization temperature to dynamically recrystallize the metal strip during hot rolling.

[0370] Example 50.5 is the system of any of Examples 1-5 or Examples 8-10, further comprising a quenching system located immediately downstream of the hot rolling stand, wherein the hot rolling stand is positioned to receive the metal strip at the rolling temperature and is configured to apply a force to the metal strip sufficient to reduce the thickness of the metal strip and recrystallize the metal strip at the rolling temperature.

[0371] Example 51 is the system of Example 50, further comprising a heat source located upstream of the hot rolling stand for heating the metal strip to a temperature above a recrystallization temperature of the metal strip on the hot rolling stand.

[0372] Example 51.5 is the system of Example 50.5, further comprising a heat source located upstream of the hot rolling stand for heating the metal strip to a rolling temperature.

[0373] Example 52 is the system of Examples 50-51.5, wherein the hot rolling stand and the quench system are arranged to monotonically reduce the temperature of the metal strip from immediately before the hot rolling stand to immediately after the quench system.

[0374] Example 53 is the system of Example 11-14 or Example 17, further comprising a quenching system located immediately downstream of at least one hot rolling stand, wherein the at least one hot rolling stand is positioned to receive the metal strip at a temperature above the recrystallization temperature for dynamically recrystallizing the metal strip as the metal strip passes through a most downstream hot rolling stand of the at least one hot rolling stand.

[0375] Example 53.5 is the system of Example 11-14 or Example 17, further comprising a quenching system located immediately downstream of at least one hot rolling stand, wherein a most downstream hot rolling stand of the at least one hot rolling stand is positioned to receive a metal strip at a rolling temperature and is configured to apply a force to the metal strip sufficient to reduce a thickness of the metal strip and recrystallize the metal strip at the rolling temperature.

[0376] Example 54 is the system of Example 53, further comprising a heat source located upstream of all at least one hot rolling stands for heating the metal strip to a temperature above a recrystallization temperature of the metal strip at the most downstream hot rolling stand.

[0377] Example 54.5 is the system of Example 53.5, further comprising a heat source located upstream of all at least one hot rolling stands for heating the metal strip to a temperature at or above the rolling temperature.

[0378] Example 55 is the system of any of Examples 53 or 54, wherein the at least one hot rolling stand and the quench system are arranged to monotonically reduce the temperature of the metal strip from immediately before all of the at least one hot rolling stand to immediately after the quench system.

[0379] Example 56 is the method of Examples 18-22 or Examples 25-26, further comprising quenching the metal strip immediately after hot rolling the metal strip, wherein hot rolling the metal strip comprises passing the metal strip through a final hot rolling stand at a temperature above a recrystallization temperature.

[0380] Example 57 is the method of Example 56, further comprising preheating the metal strip immediately prior to hot rolling the metal strip.

[0381] Example 58 is the method of Example 56 or 57, wherein throughout the process of hot rolling the metal strip and quenching the metal strip, the temperature of the metal strip decreases monotonically from a temperature above the recrystallization temperature.

[0382] Example 59 is a method comprising preheating a metal strip to a temperature above a recrystallization temperature; hot rolling the metal strip, wherein hot rolling the metal strip comprises passing the metal strip through a final hot rolling stand at a temperature above the recrystallization temperature; and quenching the metal strip, wherein the metal strip is quenched immediately after hot rolling the metal strip.

[0383] Example 59.5 is a method comprising: preheating a metal strip to a temperature at or above a rolling temperature; hot rolling the metal strip, wherein hot rolling the metal strip comprises passing the metal strip through a final hot rolling stand at the rolling temperature while applying a force to the metal strip sufficient to reduce the thickness of the metal strip and cause the metal strip to recrystallize at the rolling temperature; and quenching the metal strip, wherein the metal strip is quenched immediately after hot rolling the metal strip.

[0384] Example 60 is the method of Example 59 or 59.5, wherein hot rolling the metal strip comprises monotonically reducing the temperature of the metal strip from when the metal strip enters a first hot rolling stand to when the metal strip exits a final hot rolling stand.

[0385] Example 61 is the method of Example 59 or 59.5, wherein hot rolling the metal strip comprises monotonically reducing the temperature of the metal strip from when the metal strip enters a first hot rolling stand during hot rolling of the metal strip to immediately after quenching the metal strip.

[0386] Example 62 is the method of Examples 59-61, wherein hot rolling the metal strip includes providing a greater percentage thickness reduction in a final hot rolling stand than in one or more previous hot rolling stands.

[0387] Example 63 is the method of Examples 59-62, wherein hot rolling the metal strip includes extracting heat from the metal strip using a plurality of work rolls.

[0388] Example 64 is the method of Example 63, wherein extracting heat from the metal strip includes extracting heat sufficient to bring the temperature of the metal strip to a desired temperature as the metal strip passes through a final hot rolling stand, and wherein the desired temperature is determined based on a strain rate associated with reducing the thickness of the metal strip using the final hot rolling stand.

[0389] Example 64.5 is the method of Example 63, wherein extracting heat from the metal strip includes extracting heat sufficient to bring the temperature of the metal strip to a rolling temperature, and wherein the rolling temperature is determined based on a strain rate associated with reducing the thickness of the metal strip using a final hot rolling stand.

[0390] Example 65 is the method of Example 63, wherein the final hot rolling stand is arranged to reduce the thickness of the metal strip by a preset thickness reduction percentage, wherein the preset thickness reduction percentage and the desired temperature are determined to minimize a time period for precipitates to form in the metal strip.

[0391] Example 66 is the method of Example 63, wherein the final hot rolling stand is arranged to reduce the thickness of the metal strip by a preset thickness reduction percentage, wherein the preset thickness reduction percentage and the rolling temperature are determined to subject the metal strip to a desired amount of precipitate formation.

[0392] Example 67 is the method of Example 65 or 66, wherein the precipitate is Mg2Si.

[0393] Example 68 is a metallurgical product produced using the methods of Examples 59-67, wherein the metallurgical product is tempered to T4 specification and includes a volume fraction of Mg2Si precipitates at or below 4.0%.

[0394] Example 69 is a metallurgical product produced using the methods of Examples 59-67, wherein the metallurgical product is tempered to T4 specification and includes a volume fraction of Mg2Si precipitates at or below 3.0%.

[0395] Example 70 is a metallurgical product produced using the methods of Examples 59-67, wherein the metallurgical product is tempered to T4 specification and includes a volume fraction of Mg2Si precipitates at or below 2.0%.

[0396] Example 71 is a metallurgical product produced using the methods of Examples 59-67, wherein the metallurgical product is tempered to T4 specification and includes a volume fraction of Mg2Si precipitates at or below 1.0%.

[0397] Example 72 is the system of Examples 11-17, wherein at least one hot rolling stand is located between the continuous strip casting apparatus and the coiling apparatus for reducing the thickness of the metal strip when the continuous strip casting apparatus is not casting the metal strip.

[0398] Example 73 is an intermediate metal product comprising: a primary phase of solid aluminum formed by cooling liquid metal in a continuous casting apparatus with a strip thickness between 7 mm and 50 mm; and a secondary phase comprising alloying elements, wherein the secondary phase is spheroidized by hot working or warm working the primary and secondary phases at a cross-sectional reduction of about 30% to 80%. In some cases, the cross-sectional reduction is about 50% to 70%.

[0399] Example 73.5 is the intermediate metal product of Example 73, wherein the hot working or warm working includes hot rolling or warm rolling, and the reduction in cross-section is a reduction in thickness.

[0400] Example 74 is the metal product of example 73 or 73.5, wherein the metal product is formed into the shape of a metal strip wound into a coil.

[0401] Example 75 is the metal product of Examples 73-74, wherein the secondary phase is further spheroidized by maintaining a peak metal temperature of about 450°C-580°C in the primary and secondary phases for about 1-3 minutes followed by hot working or warm working.

[0402] Example 75.5 is the metal product of Examples 73-74, wherein the secondary phase is further spheroidized by maintaining the peak metal temperature in the primary phase and the secondary phase about 15°C-45°C below the solidus temperature of the metal product, wherein the peak metal temperature is maintained for about 1-3 minutes prior to hot working or warm working.

[0403] Example 76 is a metal casting system comprising: a continuous casting device for casting a metal strip; and one or more rolling stands located downstream of the continuous casting device for receiving the metal strip and reducing the thickness of the metal strip by about 50% to 70% at a hot rolling or warm rolling temperature.

[0404] Example 77 is the system of Example 76, wherein the continuous casting device is arranged to cast the metal strip at a thickness between 7 mm and 90 mm.

[0405] Example 78 is the system of example 76 or 77, wherein the hot rolling or warm rolling temperature is at least about 400°C.

[0406] Example 79 is the system of Examples 76-78, further comprising a soaking furnace located inline between the continuous casting device and the rolling stand for maintaining the metal strip at a peak metal temperature for about 1-3 minutes, the peak metal temperature being about 15°C-45°C below the solidus of the metal strip. In some cases, the peak metal temperature is maintained at about 450°C-580°C.

[0407] Example 80 is the system of Examples 76-79, wherein the one or more rolling stands include a single rolling stand capable of achieving a 50%-70% reduction in thickness of the metal strip.

[0408] Example 81 is the system of Examples 76-80, wherein the continuous casting apparatus is a belt caster.

[0409] Example 82 is the system of Examples 76-81, further comprising a winding device located downstream of the one or more rolling stands for winding the metal strip into a coil.

[0410] Example 83 is a method comprising: continuously casting a metal strip using a continuous casting apparatus; and hot rolling or warm rolling the metal strip to reduce the thickness by about 50%-70% after the metal strip leaves the continuous casting apparatus.

[0411] Example 84 is the method of Example 83, wherein continuously casting the metal strip comprises continuously casting the metal strip at a thickness between 7 mm and 50 mm.

[0412] Example 85 is the method of Example 83 or 84, wherein hot rolling or warm rolling comprises hot rolling at a temperature of at least about 400°C.

[0413] Example 86 is the method of Examples 83-85, further comprising maintaining the peak metal temperature about 15°C-45°C below the solidus temperature of the metal strip for about 1-3 minutes between casting the metal strip and rolling the metal strip. In some cases, the peak metal temperature is maintained at about 450°C-580°C.

[0414] Example 87 is the method of Example 86, wherein hot rolling or warm rolling the metal strip comprises reducing the thickness of the metal strip by about 50%-70% using a single rolling stand.

[0415] Example 88 is the method of Examples 83-87, wherein continuously casting the metal strip includes passing the liquid metal through a pair of rollers to extract heat from the liquid metal and solidify the liquid metal.

[0416] Example 89 is the method of Examples 83-88, further comprising winding the metal strip into a coil after warm rolling or hot rolling the metal strip.

[0417] Example 90 is the method of Examples 83-89, wherein hot rolling or warm rolling a metal strip comprises: extracting heat from the metal strip within the bite of a rolling stand; and applying a force to the metal strip to reduce the thickness of the metal strip, wherein the applied force is sufficient to recrystallize the metal strip at the temperature of the metal strip when the force is applied.

[0418] Example 91 is the method of Example 90, wherein extracting heat and applying force occur in a single rolling stand.

[0419] Example 92 is the method of Example 90, wherein extracting heat occurs in a first rolling stand and applying force occurs in a subsequent rolling stand.

[0420] Example 93 is an aluminum metal product comprising: a continuously cast aluminum alloy reduced to a thickness equal to or less than about 35 mm, wherein the continuously cast aluminum alloy contains iron present in an amount of at least 0.2 weight percent, wherein the median equivalent circular diameter of the iron-based intermetallic particles is less than about 0.8 μm.

[0421] Example 94 is the aluminum metal product of Example 93, wherein the median equivalent circle diameter of the iron-based intermetallic particles is less than about 0.75 μm.

[0422] Example 95 is the aluminum metal product of Example 93, wherein the median equivalent circle diameter of the iron-based intermetallic particles is less than about 0.65 μm.

[0423] Example 96 is the aluminum metal product of Examples 93-95, wherein the median aspect ratio of the iron-based intermetallic particles is less than about 4.

[0424] Example 97 is the aluminum metal product of Examples 93-96, wherein the continuously cast aluminum alloy is at final specifications.

[0425] Example 98 is the aluminum metal product of Examples 93-97, wherein the aluminum alloy has a gauge of approximately 2.0 mm.

[0426] Example 99 is the aluminum metal product of Examples 93-98, wherein the aluminum alloy is a 6xxx series aluminum alloy.

Claims

1. A metal casting system, comprising: Continuous casting apparatus for casting metal strip; as well as One or more rolling stands located downstream of the continuous casting device are used to receive the metal strip and reduce the thickness of the metal strip by 50% to 70% at hot rolling or warm rolling temperature, and the metal casting system also includes a soaking furnace, which is located between the continuous casting device and the one or more rolling stands and is used to maintain the metal strip at a peak metal temperature of 400°C-580°C, that is, 15°C-45°C lower than the solidus temperature of the metal strip, for a duration of 1-3 minutes, wherein the metal is aluminum, and the metal casting system also includes a post-casting quenching device located downstream of the continuous casting device, thereby forming a metal strip with a dispersion having a size of 10nm to 500nm, and quenching is performed immediately after continuous casting.

2. The metal casting system according to claim 1, wherein: The continuous casting apparatus is arranged to cast metal strip having a thickness of 7 mm to 50 mm.

3. The metal casting system of claim 1, wherein: The hot rolling or warm rolling temperature is at least 400°C.

4. The metal casting system of claim 1, wherein: The one or more rolling stands include a single rolling stand capable of achieving a 50%-70% reduction in thickness of the metal strip.

5. The metal casting system of claim 1, wherein: The continuous casting device is a belt-type continuous casting machine.

6. The metal casting system of claim 1 further comprising a coiling device located downstream of the one or more rolling stands for coiling the metal strip into a coil.

7. A method comprising: continuously casting a metal strip using a continuous casting apparatus with a post-casting quench, the post-casting quench apparatus being located immediately downstream of the continuous casting apparatus; and After the metal strip leaves the continuous casting device, the metal strip is hot rolled or warm rolled with a thickness reduction of 50%-70%, and the method also includes maintaining a peak metal temperature of 400°C-580°C between the cast metal strip and the rolled metal strip, which peak metal temperature is 15°C-45°C lower than the solidus temperature of the metal strip for a duration of 1-3 minutes, wherein the metal is aluminum and a metal strip having dispersoids with a size of 10nm to 500nm is formed, and quenching is performed immediately after continuous casting.

8. The method of claim 7, wherein continuously casting the metal strip comprises continuously casting the metal strip at a thickness of 7 mm to 50 mm.

9. The method of claim 7, wherein hot rolling or warm rolling comprises hot rolling at a temperature of at least 400°C.

10. The method of claim 7, wherein hot rolling or warm rolling the metal strip comprises reducing the thickness of the metal strip by 50% to 70% using a single rolling stand.

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