Device for rolling a metal billet

Abstract

The invention relates to a device for rolling a metal billet. The device comprises a frame on which an upper stepped roll and a lower stepped roll are disposed. The lower stepped roll and the upper stepped roll are arranged in mirror fashion relative to one another. The surfaces of the rolls form a working pass with a rectangular cross-section. Between the surfaces of the rolls which have the smallest and largest outside diameters a gap in a range of 1 to 6 mm is formed. This results in reduced metal loss and less equipment downtime caused by the formation and removal of burrs during deformation processing.

Description

[0001] DEVICE FOR ROLLING METAL BLANKS

[0002] Field of technology

[0003] The invention relates to the field of metallurgy, namely, the proposed device can be used to produce deformed semi-finished products in the form of rolled strips, rods and other semi-finished products, in particular, from aluminum and alloys based on it.

[0004] The deformed semi-finished products obtained using the device can be used as final products or as intermediate blanks for subsequent deformation, including for the production of cable and wire products and welding wire.

[0005] State of the art

[0006] Multi-stand rolling mills are typically used for the continuous production of wrought non-ferrous alloy products. These rolling mills differ primarily in the number of rolling stands, typically using a two- or three-high rolling system. The rolling mills themselves can be classified as finishing or roughing mills.

[0007] Such lines are characterized by high productivity and the ability to roll cast blanks, for example, most known materials based on aluminum or copper.

[0008] However, a significant disadvantage of such lines is their large overall dimensions and, in particular, the length of the line, which requires the allocation of large areas for production equipment.

[0009] Thus, in known solutions, plastic deformation of the cast blank is carried out uniformly, over several passes, which increases the overall size of the continuous rolling line. Among the widely used designs of rolling mills for producing wire rod, the Y-shaped arrangement of rolls is well-known. Below are some examples of known lines and rolls used in continuous rolling.

[0010] A description of a production line under CN209476915 is known, revealing the composition of equipment for producing aluminum rod. It includes a casting machine for casting aluminum alloy blanks, a straightening machine, a roller conveyor for transporting the cast aluminum alloy blank, a milling machine for removing the edges of the cast blank, a furnace for regulating the temperature of the cast blank, a continuous rolling mill, and a receiving device. The rolling mill utilizes a three-high rolling system.

[0011] A continuous casting and rolling system for grade 5356 aluminum alloy rod according to CN109127730 is known. It includes a melting furnace, a casting machine, a roughing rolling system consisting of 4 stands, a finishing rolling system consisting of 8 stands, and a receiving device. The roughing mill is separated from the finishing mill, and the rolling rolls are equipped with rolling grooves that reduce the ellipticity in the direction of rod movement to zero.

[0012] Among the three-roll rolling systems, a design according to CN219520010 is particularly noteworthy. It describes three rolling rolls arranged in a Y-shape. The angle between the axes of two adjacent rolls is 120°. A circular space is formed in the center of the three rolls for rolling the aluminum blank, where rolling is accomplished by rotation from a drive mechanism. The device is equipped with a device for cleaning the roll surfaces at the appropriate positions of each roll. A through hole is located on both sides of the housing, through which the blank passes. Among the disadvantages of this device is the inability to achieve high degrees of deformation in a single pass, necessitating the use of a system of sequentially installed rolls, as mentioned above.

[0013] A common disadvantage of continuous rolling using two- and three-roll systems is the possibility of defects forming in the form of “rolls” on the surface of the workpiece, powder, for example, due to incorrect calculation of deformation rates in multi-stand rolling mills.

[0014] A known solution is patent RU2639203, which presents a device for continuously producing a metal blank. It comprises a crystallizer that continuously forms a cast blank, a grooved roll, and a roll with a projection, which meet to form a gap. The top of the roll projection is T-shaped. Disadvantages of this known solution include uneven wear on the surface of the two rolls due to uneven loads on the rolls, which is caused by the asymmetrical design of the rolls.

[0015] A device known under patent US3017665 is designed for producing sheets from metal powder. The device comprises first and second rollers, the mating of which forms a gap between the rollers. The first roller has annular flanged sections at opposite ends of the roller, which form stops and prevent the loss of metal powder particles. The disadvantages of this device include significant loss of rolled material in the form of burrs during deformation of an infinitely long cast blank from the large gaps between the rollers.

[0016] The closest solution to the claimed invention is JPS5588905, which discloses a stepped roll design. This design is used to calibrate rolled products by rotating the rolls in different directions. A drawback of the known device using stepped rolls is the inability to roll cast blanks of infinite length. In particular, the design does not prevent burr formation. Disclosure of the invention

[0017] The objective of the invention is to ensure the deformation of a cast metal blank, in particular made of aluminum or its alloys, in a continuous mode to obtain a deformed metal blank with the formation of a minimum amount of burrs, i.e., minimizing surface defects during continuous rolling of a metal blank, primarily made of aluminum and its alloys.

[0018] The technical result of the invention is to solve the stated problem, reducing metal loss and equipment downtime associated with the formation and removal of burrs during deformation processing, and increasing the speed of deformation processing. An additional advantage is the ability to reduce the incidence of surface defects by eliminating multi-roll rough rolling and performing it in a single pass.

[0019] The proposed composite design of rolls made of rings of different outer diameters allows for an increase in the service life of the rolls due to the symmetrical design of the rings and the possibility of using the reverse sides of the rings when they wear out, as well as due to the absence of stress concentrators in the form of right angles on one part, compared to stepped rolls of a non-separable (one-piece) design.

[0020] The technical result of the invention is achieved by the proposed device for rolling a metal blank, in particular, from aluminum and its alloys.

[0021] According to the invention, the proposed device is intended for rolling metal blanks, primarily aluminum and its alloys. The device comprises a frame on which an upper stepped rolling roll and a lower stepped rolling roll are mounted using pressure washers and flanged shafts. The lower stepped roll and the upper stepped roll are arranged mirror images of each other so that: the surfaces of the rolls form a working gauge with a rectangular cross-section; and a gap (h) is formed between the surfaces with the largest and smallest outer diameters, which ranges from 1 to 6 mm.

[0022] In one embodiment of the device, the upper stepped roller and the lower stepped roller can be dismountable and represent a set of rings of variable diameter.

[0023] Also, in one of the embodiments, the preferred area of ​​the rectangular gap (3) formed when mating the stepped shaft (1) and the stepped shaft (2) is in the range of 840-1620 mm 2 The preferred gap size h is in the range of 4.5-5.4 mm.

[0024] It is important to note that the proposed device can be coupled with other deformation devices, providing the possibility of continuous deformation of a metal workpiece.

[0025] In one embodiment, the proposed device provides deformation of a continuously moving workpiece at a speed of up to 14.7 m / min.

[0026] The upper stepped rolling roll and the lower stepped rolling roll have a splined connection with the cylindrical part of the shafts.

[0027] Shafts, rings and pressure washers have external and / or internal cooling.

[0028] Thanks to the proposed invention, when implementing a continuous process of rolling blanks from aluminum and its alloys, metal losses are reduced and equipment downtime associated with the formation and / or removal of metal burrs is reduced, the rate of deformation of the cast blank is increased, and the number of defects is reduced.

[0029] The essence of the invention is explained in the drawings.

[0030] Fig. 1 shows a schematic diagram of the proposed device for continuous rolling of a workpiece made of aluminum and its alloys.

[0031] Fig. 2 shows a diagram of the composite roller structure. The rationale and design of the device, which provides a solution to the stated problem and achieves the stated technical result, including in terms of improving the continuous deformation process of a cast aluminum and its alloy blank, is presented below as an example of a specific embodiment of the invention.

[0032] In order to implement the invention, it is proposed to use stepped rolls (1) and (2) arranged symmetrically and mirror-image relative to each other, provided that the axes of each roll are parallel and the rolls are rigidly fixed relative to each other on the frame. Along the horizontal axis, rolls (1) and (2) should adjoin each other, ensuring free rotation relative to each other. The stepped shape of each of the rolls (1) and (2) is regulated in such a way that when mated to each other, surfaces (4), (5), (8), (9), (10), (11) of each of the rolls (1) and (2) would form the following gaps:

[0033] - gap (3) for deformation of the cast blank;

[0034] - technological gap (h) between the surfaces of the rolls, which prevents the development of the spread of burrs formed during rolling of cast blanks made of aluminum and its alloys.

[0035] The authors unexpectedly found that preventing the spread of burrs is associated with limiting the size of the technological gap (h) to 6 mm, at which the flow of metal at an angle of 90 degrees relative to the original direction becomes impossible.

[0036] The minimum value of the gap (h) is limited to 1 mm, since at a value of less than 1 mm, additional friction of the roll surfaces relative to each other may occur, for example, due to deviation in the parallelism of the axes, thermal expansion of the device structure during rolling under elevated temperature conditions, etc.

[0037] The maximum value of the gap (h) is limited to 6 mm, since at values ​​greater than 6 mm it becomes possible for aluminum and its alloys to flow at an angle of 90 degrees relative to the original direction of movement, with the subsequent formation of an uncontrolled amount of burrs and metal loss.

[0038] The proposed design can be used for continuous deformation of materials in a wide range of degrees of deformation, in particular, from 10 to 50% depending on the processability of the material.

[0039] The design of the device can be used not only for continuous deformation of aluminum and its alloys, but also for other materials, such as copper-based, magnesium-based, etc., which speaks to its versatility.

[0040] Stepped rolls can have internal cooling, which prevents them from heating up due to the passage of a heated workpiece in the working gauge, as well as external cooling of the working surfaces of the stepped rolls, which prevents the extrusion of metal from the working gauge through gaps.

[0041] Detailed disclosure of the invention

[0042] The proposed device (Fig. 1) contains:

[0043] 1 - upper stepped roller;

[0044] 2 - lower stepped roller;

[0045] 3 - a rectangular gap formed when the upper stepped shaft and the lower stepped roll are connected;

[0046] 4 - the surface of the upper stepped roll, which acts on the metal workpiece in the radial direction of the roll;

[0047] 5 - the surface of the lower stepped roll, which acts on the metal workpiece in the radial direction of the roll;

[0048] 6 - the surface of the upper stepped roll, acting on the metal workpiece in the axial direction of the roll;

[0049] 7 - surface of the lower stepped roll, acting on the metal workpiece in the axial direction of the roll; 8, 9, 10 11 - additional surfaces of the upper and lower stepped roll, forming a technological gap h, preventing the formation of burrs.

[0050] Fig. 2 shows a variant of the composite roller design, in particular, the upper stepped roller of the device is shown, containing a set of rings with a schematic indication of an internal cooling channel providing heat dissipation. According to the variant of the invention of the composite design, the roller rings are pressed against the flange (12) of the roller (1) by means of a bolted connection (bolted connections are not shown in the diagram of Fig. 2).

[0051] If necessary, the device can be cooled by external cooling through the use of external sprinklers.

[0052] The working fluid used in the cooling channel can be liquids or gases, such as water, nitrogen, etc.

[0053] Taking into account that the surfaces forming the rectangular gap (3) wear out over time, in particular, surfaces (6) and (7) are subject to great wear due to friction with the workpiece during rolling, then, thanks to the composite design of the roll, the service life of the device can be increased by rearranging the corresponding rings of the upper and lower stepped rolls by 180°.

[0054] Examples of specific implementations of device variants

[0055] Below are examples of specific implementations of the invention. The purpose of this example is to justify the selection of process gap values ​​(h) in the device design, which ensures continuous deformation of the cast blank, achieving the stated technical result. The gap value (h) was varied by adjusting the position of the upper stepped roll (1) relative to the lower stepped roll (2) using a wedge clamp. The cast blank was produced by continuous casting on a wheel with a diameter of 1510 mm. Next, to implement the invention, the cast blank was guided into the gap (3) and then deformed to the specified cross-section.

[0056] Example 1

[0057] A deformable blank was produced from technical aluminum grade 1350 using a continuous method according to the parameters given in Table 1. The initial cross-sections of the cast aluminum blanks were 1232, 1600 and 2025 mm 2To ensure processability, the initial temperature of the blanks was maintained in the range of 250–400°C. The speed of the cast 1350 alloy blank before entering the device was 12 m / min. Rolling of the cast blank (rough rolling) was completed in a single pass.

[0058] Rolling of the cast blank was carried out at different values ​​of the gap h, while the gap size was selected within the range from 1 to 8 mm.

[0059] Table 1. Parameters for rolling continuous billets made of 1350 grade aluminum alloy. From the obtained results presented in Table 1, it follows that when the condition is met in which the gap h in the device is in the range from 1 to 6 mm, continuous rolling of the 1350 alloy blank is ensured without the formation of burrs that would hinder the continuous deformation process.

[0060] Experiments revealed increased friction between the upper and lower rolls at gaps less than 1 mm. At gaps h greater than 6 mm, uncontrolled burr formation was observed, preventing continuous operation and resulting in significant metal loss. In this case, the process was halted due to uncontrollably high metal loss. Thus, with increasing gap h, increased burr formation was observed under the rolling parameters used.

[0061] The minimum amount of burrs is found when the gap h value is set in the range of 4.5-5.4 mm; the specified range of gap h values ​​is the most optimal and preferable.

[0062] Example 2

[0063] A cast blank of grade 4043 Al-Si alloy was deformed within the h-value range defined above. The deformation parameters are presented in Table 2. The initial temperature of the cast blank was in the range of 250–350°C.

[0064] Table 2. Parameters for rolling continuous billets made of alloy grade 4043.

[0065] From the obtained results (Table 2) it follows that when the condition is met in which the gap h in the device is in the range from 1 to 6 mm, continuous rolling of the 4043 alloy blank is ensured without the formation of burrs that would hinder the continuous deformation process.

[0066] Example 3

[0067] The effect of cast blank speed on burr formation was determined. A deformable blank was produced from grade 1350 aluminum using a continuous casting process, according to the parameters listed in Table 3. The blank speed was varied by changing the casting wheel rotation speed. Table 3 shows the linear speed of the cast blank as a calculated value obtained by multiplying the angular speed of the casting wheel by the casting wheel radius.

[0068] Table 3. Parameters for rolling continuous billets made of alloy grade 1350.

[0069] The results (Table 3) show that cutting speeds up to 14.7 m / min have no effect on burr formation. Increasing the speed to 15.9 m / min had a negative impact on the amount of burr formed.

[0070] Example 4

[0071] Below is a confirmation of the proposed device's use in a continuous casting and rolling line for aluminum or its alloy rod. Specifically, the proposed device is integrated into a casting and rolling line comprising the following equipment:

[0072] - a melting furnace (mixer) for the preparation and handling of molten aluminum for casting; - a casting wheel designed for the crystallization of molten aluminum or its alloy to produce a cast blank with a cross-section in the range of 1232 - 2025 mm 2 ;

[0073] - auxiliary equipment designed to regulate the temperature of the cast blank in the temperature range of 300 - 540 °C;

[0074] - the proposed device for continuous rolling of a cast blank according to the present invention to obtain a rolled deformed semi-finished product with a cross-section in the range of 840 - 1620 mm 2 ;

[0075] - dies for pressing rolled deformed semi-finished products to obtain pressed rods with a diameter in the range of 15-19 mm;

[0076] - a rolling mill for finishing rolling of pressed rods to produce rolled wire rod in the range of 8-12 mm;

[0077] - auxiliary equipment designed for cooling rolled wire rod to a temperature of 40-200 °C;

[0078] - winding equipment designed for winding cooled wire rod with a diameter of 15-19 mm into a coil.

[0079] The line can be equipped with additional auxiliary equipment, such as shears for cutting cast blanks.

[0080] Within the above-defined list of equipment for the continuous wire rod production line, a cast blank was obtained and its deformation into wire rod made of technical aluminum and aluminum alloy grade 4043 based on the Al-Si system.

[0081] The gap h was adjusted within the range of 4.5–5.4 mm. The lower stepped roller and the upper stepped roller were either solid or detachable, containing variable-diameter components.

[0082] Table 4 shows the tensile mechanical properties of 1350 H14 grade technical aluminum and 4043 O aluminum alloy wire rod produced on the line with the equipment described above. Tensile testing was performed on rod with a gauge length of 200 mm, using the method in accordance with GOST 1497.

[0083] Table 4. Typical mechanical properties of aluminum grade 1350 H14 and aluminum alloy 4043

[0084] The example above demonstrates the feasibility of eliminating the roughing mill in a continuous production line for 1350 technical aluminum and 4043 aluminum alloy wire rod. This improved the wire rod surface quality by reducing powder formation during rolling by up to 1.4 times.

[0085] In the case of using a composite design of rolls made of rings of different outer diameters, the service life of the rolls was increased by more than 2 times due to the use of the reverse sides of the roll rings during wear.

[0086] Taking into account the description and examples, the scope of legal protection is claimed for a device for rolling a metal blank, in particular from aluminum and its alloys, comprising a frame on which an upper stepped rolling roll and a lower stepped rolling roll are placed using pressure washers and shafts with flanges, wherein the lower stepped roll and the upper stepped roll are arranged mirror images of each other in such a way that: the surfaces of the rolls form a working groove with a rectangular cross-section; between the surfaces with the largest and smallest outer diameters, a gap (h) is formed, which is in the range from 1 to 6 mm. It is preferable that the upper stepped roll and the lower stepped roll are made disassemblable and contain a set of rings of variable diameter. Optimally, the area of ​​the rectangular gap formed by the mating of the upper stepped roll and the lower stepped roll is in the range of 840-1620 mm 2It is also optimal for the gap size h to be in the range of 4.5-5.4 mm. It is advisable for the upper stepped rolling roll and the lower stepped rolling roll to have a splined connection with the cylindrical portion of the shafts. The shafts, rings, and pressure washers in the device have external and / or internal cooling.

[0087] The proposed device can be coupled with deformation devices that enable continuous deformation of a metal workpiece. The device enables deformation of a continuously moving workpiece at speeds of up to 14.7 m / min.

[0088] The device is used to produce deformed semi-finished products, for example, in the form of rolled strips and rods, from aluminum and aluminum-based alloys, providing the advantages listed above.

Claims

CLAUSES OF THE INVENTION 1. A device for rolling a metal blank, comprising a frame on which an upper stepped rolling roll and a lower stepped rolling roll are placed using pressure washers and shafts with flanges, characterized in that the lower stepped roll and the upper stepped roll are arranged mirror images relative to each other, wherein: the surfaces of the rolls form a working gauge with a rectangular cross-section, between the surfaces with the largest and smallest outer diameters a gap (h) is formed, which is in the range from 1 to 6 mm.

2. The device according to paragraph 1, characterized in that the upper stepped roller and the lower stepped roller are made dismountable and contain a set of rings of variable diameter.

3. The device according to item 1, characterized in that it is used to obtain deformed semi-finished products, for example, in the form of rolled strips and rods, preferably made of aluminum and its alloys.

4. The device according to paragraph 1, characterized in that the area of ​​the rectangular gap formed when the upper stepped roll and the lower stepped roll are connected is in the range of 840-1620 mm 2 .

5. The device according to claim 1, characterized in that the size of the gap (h) is preferably in the range of 4.5-5.4 mm.

6. The device according to paragraph 1, characterized in that it ensures deformation of a continuously moving workpiece at a speed of up to 14.7 m / min.

7. The device according to item 1, characterized in that the upper stepped rolling roll and the lower stepped rolling roll have a splined connection with the cylindrical part of the shafts.

8. The device according to item 1, in which the shafts, rings and pressure washers have external and / or internal cooling.

9. The device according to paragraph 1, characterized in that it is designed with the possibility of coupling with deformation devices that ensure the possibility of continuous deformation of a metal workpiece.

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