A method of observing inclusion formation and growth after aluminum deoxidation

Abstract

The application relates to a method for observing the formation and growth of inclusions after aluminum deoxidization, and belongs to the technical field of in-situ observation experiments of high-temperature confocal microscopes. The method comprises the following steps: heating a non-deoxidized steel sample in a high-temperature laser confocal microscope under an inert atmosphere to obtain liquid steel; adding a metal aluminum sample into the liquid steel to melt; and then using a high-temperature laser confocal microscope to perform synchronous in-situ observation after the metal aluminum is added to obtain information about the formation and growth of inclusions after aluminum deoxidization. The method uses a high-temperature confocal microscope to realize online observation of the growth process of inclusions in liquid steel after aluminum deoxidization at high temperature, can effectively record the information features such as the morphology and size of the inclusions from the beginning of the growth to the end after aluminum deoxidization, and can complete the law of the growth of the inclusions with time through the recorded information, thereby providing better guidance and reference for actual production.

Description

Technical Field

[0001] This application relates to the field of in-situ observation experimental technology using high-temperature confocal microscopy, and in particular to a method for observing the formation and growth of inclusions after aluminum deoxidation. Background Technology

[0002] In steel production, the addition of aluminum serves to adjust the composition of steel, specifically the aluminum content. More importantly, aluminum removes oxygen from the steel, reducing its oxygen content and improving the cleanliness of the molten steel. Many types of deoxidizers are used in steel production, with Al and ferrosilicon manganese being the most common. Aluminum inclusions have high melting points and lack good deformation ability during rolling. Furthermore, the oxygen products from aluminum readily polymerize and grow, negatively impacting the steel's properties if they remain. Therefore, observing the growth behavior of inclusions after aluminum deoxidation is particularly important.

[0003] Traditional methods involve sampling and analysis in industrial settings or adding aluminum during pilot-scale smelting followed by sampling. However, the sampling intervals are relatively long, and cooling and oxidation increase the inaccuracy of the analysis. Currently, there are no reported methods for online in-situ observation of the formation and growth process of inclusions after aluminum deoxidation. Summary of the Invention

[0004] This application provides a method for observing the formation and growth of inclusions after aluminum deoxidation, in order to solve the technical problem that there are currently no reported methods for online in-situ observation of the formation and growth process of inclusions after aluminum deoxidation.

[0005] In a first aspect, this application provides a method for observing the formation and growth of inclusions after aluminum deoxidation, the method comprising:

[0006] Under an inert atmosphere, an undeoxidized steel sample in a high-temperature laser confocal microscope is heated to obtain liquid steel.

[0007] Aluminum samples were added to the molten steel for melting, and then a high-temperature laser confocal microscope was used for simultaneous in-situ observation after the addition of aluminum to obtain information on the formation and growth of inclusions after aluminum deoxidation.

[0008] Furthermore, the steel sample comprises the following components by weight fraction:

[0009] C: 0.01wt%~1wt%; Si: 0.005wt%~0.2wt%; Mn: 0.1wt%~1wt%; P: 0.003wt%~0.08wt%; S: 0.0005wt%~0.01wt%; the remainder is Fe.

[0010] Furthermore, the heating parameters include: a heating temperature of 1500–1600°C and a heating time of 60–300 seconds.

[0011] Furthermore, the steel sample is cylindrical in shape.

[0012] Furthermore, the steel sample has the following dimensions: a diameter of 6–7.5 mm and a height of 1–3 mm.

[0013] Furthermore, the preparation process of the steel sample includes:

[0014] The steel sample is cut according to the preset size, and then the surface is ground, polished and cleaned to obtain the steel sample.

[0015] Furthermore, the aluminum sample is spherical with a diameter of 1 to 5 mm.

[0016] Furthermore, the high-temperature laser confocal microscope includes a high-temperature confocal microscope body; and

[0017] The material addition component is located on the body of the high-temperature confocal microscope;

[0018] The material adding component is used to add aluminum metal in situ at high temperatures.

[0019] Furthermore, the material adding component includes: a first material inlet located on the surface of the furnace cover, a first sliding sliding component located on the surface of the furnace cover, and a second sliding sliding component located on the surface of the furnace cover;

[0020] The material inlet is connected to a second material inlet located inside the furnace cover;

[0021] The first sliding component and the second sliding component form a concentric cylindrical rotating device. The first sliding component is located on the outside of the cylindrical rotating device, and the second sliding component is located on the inside of the cylindrical rotating device.

[0022] Furthermore, the cylindrical rotating device is connected to a first sliding plate and a second sliding plate.

[0023] The technical solutions provided in this application have the following advantages compared with the prior art:

[0024] The method provided in this application uses a high-temperature confocal microscope to observe the growth process of inclusions in molten aluminum after deoxidation at high temperatures. It can effectively record the morphology and size characteristics of inclusions after deoxidation from the beginning to the end of growth, and use the recorded information to determine the law of the growth of inclusions after deoxidation over time, providing better guidance and reference for actual production. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0026] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 A flowchart illustrating a method for observing the formation and growth of inclusions after aluminum deoxidation, provided in an embodiment of this application;

[0028] Figure 2 Schematic diagram of the structure of the high-temperature confocal microscope provided in the embodiments of this application Figure 1 ;

[0029] Figure 3 Schematic diagram of the structure of the high-temperature confocal microscope provided in the embodiments of this application Figure 2 ;

[0030] Wherein, 1-fixed device, 2-first material inlet, 3-first sliding blade sliding component, 4-second sliding blade sliding component, 5-observation hole, 6-exterior of focusing device, 7-first sliding blade, 8-second sliding blade, 9-second material inlet, 10-interior of focusing device. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0032] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0033] In steel production, the addition of aluminum serves to adjust the composition of steel, specifically the aluminum content. More importantly, aluminum removes oxygen from the steel, reducing its oxygen content and improving the cleanliness of the molten steel. Many types of deoxidizers are used in steel production, with Al and ferrosilicon manganese being the most common. Aluminum inclusions have high melting points and lack good deformation ability during rolling. Furthermore, the oxygen products from aluminum readily polymerize and grow, negatively impacting the steel's properties if they remain. Therefore, observing the growth behavior of inclusions after aluminum deoxidation is particularly important.

[0034] Traditional methods involve sampling and analysis in industrial settings or adding aluminum during pilot-scale smelting followed by sampling. However, the sampling intervals are relatively long, and cooling and oxidation increase the inaccuracy of the analysis. Currently, there are no reported methods for online in-situ observation of the formation and growth process of inclusions after aluminum deoxidation.

[0035] The technical solution provided by the embodiments of the present invention is to solve the above-mentioned technical problems, and the general idea is as follows:

[0036] like Figure 1 As shown in the embodiments of this application, a method for observing the formation and growth of inclusions after aluminum deoxidation is provided, the method comprising:

[0037] Under an inert atmosphere, an undeoxidized steel sample in a high-temperature laser confocal microscope is heated to obtain liquid steel.

[0038] Aluminum samples were added to the molten steel for melting, and then a high-temperature laser confocal microscope was used for simultaneous in-situ observation after the addition of aluminum to obtain information on the formation and growth of inclusions after aluminum deoxidation.

[0039] As one embodiment of this application, the steel sample comprises the following components by weight fraction:

[0040] C: 0.01wt%~1wt%; Si: 0.005wt%~0.2wt%; Mn: 0.1wt%~1wt%; P: 0.003wt%~0.08wt%; S: 0.0005wt%~0.01wt%; the remainder is Fe.

[0041] In this application, in order to better reflect the actual production process of iron and steel smelting, the above-mentioned steel samples were used to observe the melting of scrap steel, and the results obtained are more practically instructive.

[0042] As one embodiment of this application, the heating parameters include: heating temperature of 1500-1600℃ and heating time of 60s-300s.

[0043] In this application, controlling the heating parameters to the above-mentioned parameters can ensure the complete melting of the steel sample.

[0044] In one embodiment of this application, the steel sample is cylindrical.

[0045] As one embodiment of this application, the steel sample has the following dimensions: diameter of 6-7.5 mm and height of 1-3 mm.

[0046] In this application, when the steel sample size is controlled to the above parameters, it can be used in conjunction with a high-temperature laser confocal microscope to facilitate sample loading.

[0047] As one embodiment of this application, the preparation process of the steel sample includes:

[0048] The steel sample is cut according to the preset size, and then the surface is ground, polished and cleaned to obtain the steel sample.

[0049] In this application, the preparation process of the aforementioned steel sample can specifically be as follows:

[0050] Undeoxidized steel samples were prepared by wire cutting. The samples were cylindrical with a diameter of 6–7.5 mm and a height of 1–3 mm. The surface of the samples was rough-ground and fine-ground, and polished with diamond polishing agent. The polished surface of the samples was then cleaned with an 80–90% ethanol solution. The aluminum samples were then placed in an ultrasonic cleaner and cleaned with an 80–90% ethanol solution for 10 minutes.

[0051] In one embodiment of this application, the aluminum sample is spherical with a diameter of 1 to 5 mm.

[0052] In this application, when the size of the aluminum sample is controlled to the above parameters, it can be used in conjunction with a high-temperature laser confocal microscope to facilitate sample loading.

[0053] As one embodiment of this application, the high-temperature laser confocal microscope includes a high-temperature confocal microscope body; and

[0054] The material addition component is located on the body of the high-temperature confocal microscope;

[0055] The material adding component is used to add aluminum metal in situ at high temperatures.

[0056] like Figure 2-3 As shown, the high-temperature confocal microscope includes a high-temperature confocal microscope body; and

[0057] The material addition component is located on the body of the high-temperature confocal microscope;

[0058] The material adding component is used to add materials in situ at high temperatures.

[0059] Specifically, this high-temperature confocal microscope adds a first material inlet 2 to the existing furnace cover of a high-temperature confocal microscope. A screw above the first material inlet 2 serves as a cover to prevent material oxidation. The first material inlet 2 is a vertically perforated hole in the entire cover for adding material. This vertically perforated hole connects to a second material inlet 9 inside the furnace cover. The second scribe 8 has holes of the same size and position, connecting to the material inlet 2 in the vertical direction of the furnace cover. The first scribe 7 and the second scribe 8 are connected by a rotating device, namely the first scribe sliding component 3 and the second scribe sliding component 4. By sliding the first scribe sliding component 3, the first scribe 7 rotates; by sliding the second scribe sliding component 4, the second scribe 8 rotates. Sliding the second scribe sliding component 4 alone causes both the first scribe 7 and the second scribe 8 to rotate simultaneously, while sliding the first scribe sliding component 3 alone causes only the first scribe 7 to rotate. The first scribe 7 is located below the second scribe 8. One-seventh to one-fifth of the circumference of the outer perimeter of the focusing device 6 inside the furnace cover of the original high-temperature confocal microscope is removed. Simultaneously, the thickness of both the first scribe 7 and the second scribe 8 is increased to the same height as the outer perimeter of the focusing device 6 inside the furnace cover. Furthermore, the maximum rotation angle of the second scribe 8 is such that, after counterclockwise rotation, the center point of the hole for adding material on the second scribe 8 aligns with the center point of the observation hole 5 in the vertical direction of the furnace cover. Simultaneously, after the first scribe 7 and the second scribe 8 are traced clockwise from the center point of the observation hole 5, they precisely align with the outer perimeter of the focusing device 6.

[0060] The specific operation is as follows: After the material is added through the first material inlet 2, both the first scribe 7 and the second scribe 8 remain concentric with scribe 6. At this time, the material is in the furnace cover adding device, specifically in the hole of the second scribe 8 above the first scribe 7. When the high-temperature confocal microscope heats up to the required temperature, the scribe device 4 is slid counterclockwise, and the first scribe 7 and the second scribe 8 simultaneously rotate towards the center of the circle outside the focusing device 6. When the center point of the hole of the second scribe 8 coincides with the center point of the observation hole 5 in the vertical direction of the furnace cover, the device 3 is slid clockwise, and the first scribe 7 is precisely engaged with the outside of the focusing device 6. At this time, the material falls into the dry pot below for experimental research. Then, the scribe device 4 is slid clockwise, and the second scribe 8 is precisely engaged with the outside of the focusing device 6. At this time, the in-situ material adding process ends.

[0061] The present application is further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the application. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national standards. If there is no corresponding national standard, then general international standards, conventional conditions, or conditions recommended by the manufacturer are followed.

[0062] Example 1

[0063] This example provides a method for observing the formation and growth of inclusions after aluminum deoxidation, including the following process:

[0064] (1) Undeoxidized steel samples were prepared by wire cutting. The samples were cylindrical with a diameter of 6-7.5 mm and a height of 1-3 mm. The surface of the sample was rough-ground and fine-ground. The surface of the steel sample was polished with diamond polishing agent and then cleaned with 80-90% ethanol solution. The aluminum sample was then placed in an ultrasonic cleaner and the entire aluminum-killed steel sample was cleaned with 80-90% ethanol solution for 10 min.

[0065] (2) The prepared steel sample is placed in a container, which is then placed in the metallographic furnace of a high-temperature laser confocal microscope. The furnace lid is fitted with an in-situ addition device (e.g., Figure 2-3 (As shown). Metallic aluminum is added through the feeding port of the in-situ adding device. The metallic aluminum is spherical or near-spherical in shape with a diameter of 1–5 mm. The metallic aluminum remains in the in-situ adding device.

[0066] (3) The composition of the undeoxidized steel prepared is C 0.01wt% to 1wt%, Si 0.005wt% to 0.2wt%, Mn 0.1wt% to 1wt%, P 0.003wt% to 0.08wt%, S 0.0005wt% to 0.01wt%, and the remainder is Fe;

[0067] (4) After the metallographic heating furnace is evacuated, inert gas is continuously introduced. The steel sample is radiated and heated by infrared rays emitted by a high-temperature laser confocal microscope. The sample is measured in real time by an R-type thermocouple provided with the high-temperature laser confocal microscope. The steel sample is heated to 1500-1600°C and kept at a constant temperature for 60-300 seconds.

[0068] (5) Rotate the in-situ addition device to make the aluminum drop into the liquid steel. Continue to keep it warm and use the imaging system of the high-temperature laser confocal microscope to perform high-speed scanning on the surface of the liquid steel to realize synchronous in-situ observation of the reaction after the addition of aluminum, and record the morphology and size of the inclusions generated from the beginning to the end of the deoxidation of aluminum.

[0069] (6) By recording information, the behavior of inclusion growth after deoxidation of metallic aluminum is determined, providing guidance for actual production;

[0070] (7) The inert gas is argon. When the molten steel sample is radiated and heated by infrared rays emitted by the high-temperature laser confocal microscope, the infrared rays are emitted by a 1.5KW halogen light source.

[0071] (8) When the laser beam emitted by the high-temperature laser confocal microscope irradiates the surface of the steel sample, the laser beam is a He-Ne laser beam. When the imaging system of the high-temperature laser confocal microscope is used to perform high-speed scanning of the molten steel surface, the scanning speed is 50 frames / second. After evacuating the metallographic furnace, the vacuum level inside the metallographic furnace is maintained at 10... -3 ~10 -4 Torr.

[0072] (9) such as Figure 2-3 As shown, the high-temperature confocal microscope includes a high-temperature confocal microscope body; and

[0073] The material addition component is located on the body of the high-temperature confocal microscope;

[0074] The material adding component is used to add materials in situ at high temperatures.

[0075] Specifically, this high-temperature confocal microscope adds a first material inlet 2 to the existing furnace cover of a high-temperature confocal microscope. A screw above the first material inlet 2 serves as a cover to prevent material oxidation. The first material inlet 2 is a vertically perforated hole in the entire cover for adding material. This vertically perforated hole connects to a second material inlet 9 inside the furnace cover. The second scribe 8 has holes of the same size and position, connecting to the material inlet 2 in the vertical direction of the furnace cover. The first scribe 7 and the second scribe 8 are connected by a rotating device, namely the first scribe sliding component 3 and the second scribe sliding component 4. By sliding the first scribe sliding component 3, the first scribe 7 rotates; by sliding the second scribe sliding component 4, the second scribe 8 rotates. Sliding the second scribe sliding component 4 alone causes both the first scribe 7 and the second scribe 8 to rotate simultaneously, while sliding the first scribe sliding component 3 alone causes only the first scribe 7 to rotate. The first scribe 7 is located below the second scribe 8. One-seventh to one-fifth of the circumference of the outer perimeter of the focusing device 6 inside the furnace cover of the original high-temperature confocal microscope is removed. Simultaneously, the thickness of both the first scribe 7 and the second scribe 8 is increased to the same height as the outer perimeter of the focusing device 6 inside the furnace cover. Furthermore, the maximum rotation angle of the second scribe 8 is such that, after counterclockwise rotation, the center point of the hole for adding material on the second scribe 8 aligns with the center point of the observation hole 5 in the vertical direction of the furnace cover. Simultaneously, after the first scribe 7 and the second scribe 8 are traced clockwise from the center point of the observation hole 5, they precisely align with the outer perimeter of the focusing device 6.

[0076] The specific operation is as follows: After the material is added through the first material inlet 2, both the first scribe 7 and the second scribe 8 remain concentric with scribe 6. At this time, the material is in the furnace cover adding device, specifically in the hole of the second scribe 8 above the first scribe 7. When the high-temperature confocal microscope heats up to the required temperature, the scribe device 4 is slid counterclockwise, and the first scribe 7 and the second scribe 8 simultaneously rotate towards the center of the circle outside the focusing device 6. When the center point of the hole of the second scribe 8 coincides with the center point of the observation hole 5 in the vertical direction of the furnace cover, the device 3 is slid clockwise, and the first scribe 7 is precisely engaged with the outside of the focusing device 6. At this time, the material falls into the dry pot below for experimental research. Then, the scribe device 4 is slid clockwise, and the second scribe 8 is precisely engaged with the outside of the focusing device 6. At this time, the in-situ material adding process ends.

[0077] In summary, the embodiments of this application provide a method for observing the formation and growth of inclusions after aluminum deoxidation. By using a high-temperature confocal microscope, the growth process of inclusions in molten aluminum after deoxidation can be observed online at high temperatures. This method can effectively record the morphology and size characteristics of inclusions after aluminum deoxidation from the beginning to the end of their growth, and use the recorded information to determine the law of the growth of inclusions after aluminum deoxidation over time, providing better guidance and reference for actual production.

[0078] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the range referred to.

[0079] In this application, unless otherwise stated, directional terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. Furthermore, in the description of this application, terms such as "comprising" and "including" mean "including but not limited to." In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this document, "and / or" describes the relationship between related objects, indicating that three relationships can exist; for example, A and / or B can represent: A alone, A and B simultaneously, or B alone. A and B can be singular or plural. In this document, "at least one" means one or more, and "more than one" means two or more. "At least one," "at least one of the following," or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, "at least one of a, b, or c" or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be a single or multiple.

[0080] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for observing the formation and growth of inclusions after aluminum deoxidation, characterized in that, The method includes: Under an inert atmosphere, an undeoxidized steel sample in a high-temperature laser confocal microscope is heated to obtain liquid steel. A metallic aluminum sample was added to the liquid steel for melting, and then a high-temperature laser confocal microscope was used to conduct synchronous in-situ observation after the addition of metallic aluminum to obtain information on the formation and growth of inclusions after aluminum deoxidation. The high-temperature laser confocal microscope includes a high-temperature confocal microscope body and a material addition component located on the high-temperature confocal microscope body. The material addition component is used to add metallic aluminum in situ at high temperature. The material adding component includes: a first material inlet located on the surface of the furnace cover, a first sliding sliding component located on the surface of the furnace cover, and a second sliding sliding component located on the surface of the furnace cover. The material inlet is connected to the second material inlet located inside the furnace cover. The first sliding sliding component and the second sliding sliding component form a concentric cylindrical rotating device. The first sliding sliding component is located on the outside of the cylindrical rotating device, and the second sliding sliding component is located on the inside of the cylindrical rotating device. The cylindrical rotating device is connected to the first sliding blade and the second sliding blade. When the aluminum sample is added from the first material inlet, it stays in the hole of the second scribe above the first scribe. When the high-temperature confocal microscope is heated to the required temperature, the hole of the second scribe is made to coincide with the center point of the observation hole in the vertical direction of the furnace cover by sliding. The first scribe is just in contact with the outside of the focusing device, and the aluminum sample falls into the liquid steel below.

2. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 1, characterized in that, The steel sample comprises the following components by weight fraction: C: 0.01 wt%~1 wt%; Si: 0.005 wt%~0.2 wt%, Mn: 0.1 wt%~1 wt%, P: 0.003 wt%~0.08wt%, S: 0.0005 wt%~0.01 wt%, and the rest is Fe.

3. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 1, characterized in that, The heating parameters include: heating temperature of 1500-1600℃ and heating time of 60s-300s.

4. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 1, characterized in that, The steel sample is cylindrical in shape.

5. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 4, characterized in that, The steel sample has the following dimensions: diameter 6~7.5mm and height 1~3mm.

6. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 1, characterized in that, The preparation process of the steel sample includes: The steel sample is cut according to the preset size, and then the surface is ground, polished and cleaned to obtain the steel sample.

7. The method for observing the formation and growth of inclusions after aluminum deoxidation according to claim 1, characterized in that, The aluminum sample is spherical with a diameter of 1-5 mm.

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