Asynchronous differential temperature collaborative rolling process for high manganese steel plate

Abstract

The invention relates to the technical field of steel hot rolling, and provides a high-manganese steel plate asynchronous differential temperature synergistic rolling process which comprises the following steps: S1, mixing, smelting and forging all components of a high-manganese steel plate to obtain a high-manganese steel plate casting blank; s2, the high-manganese steel plate blank is subjected to heating, asymmetrical rolling and controlled cooling after rolling, and the high-manganese steel plate blank is obtained; s3, the high-manganese steel plate blank is subjected to heat treatment, and the high-manganese steel plate is obtained; the asynchronous rolling is asynchronous differential temperature cooperative rolling; in the asynchronous and differential temperature collaborative rolling process, asynchronous rolling and differential temperature rolling are carried out at the same time; during asynchronous differential temperature synergistic rolling, the different speed ratio is 1.05-1.25, the temperature of the core of the rolled piece is larger than the temperatures of the upper and lower surfaces of the rolled piece, the temperatures of the upper and lower surfaces of the rolled piece are equal, and the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20-100 DEG C. Through the technical scheme, the problem of poor permeability of the core part of the high-manganese steel plate in the related technology is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of hot rolling of steel, and specifically, to an asynchronous differential temperature collaborative rolling process for high manganese steel plates. Background Art

[0002] High manganese steel plates are widely used in the fields of construction machinery, mining equipment, etc. due to their excellent wear resistance and high toughness. However, the high manganese steel plates produced by traditional rolling processes have problems such as poor core permeability, which restricts their comprehensive performance and service life.

[0003] The processing and manufacturing process has an important impact on the performance of high manganese steel plates. Compared with synchronous rolling, asymmetric rolling technology is more conducive to increasing the deformation permeability of the plate. Among them, asynchronous rolling and differential temperature rolling have attracted much attention because they are easy to implement on existing industrial rolling mills. However, when the two are rolled collaboratively, it is difficult for traditional rolling processes to determine key parameters such as the speed ratio difference and reduction rate between the lower working roll and the upper working roll, resulting in poor improvement effect on the core permeability of high manganese steel plates.

[0004] Therefore, proposing an asynchronous differential temperature collaborative rolling process for high manganese steel plates is of great significance for improving core permeability and expanding the application range of high manganese steel plates. Summary of the Invention

[0005] The present invention proposes an asynchronous differential temperature collaborative rolling process for high manganese steel plates, which solves the problem of poor core permeability of high manganese steel plates in related technologies.

[0006] The technical solution of the present invention is as follows: The present invention proposes an asynchronous differential temperature collaborative rolling process for high manganese steel plates, including the following steps: S1. Mix the components of the high manganese steel plate, smelt and forge to obtain a high manganese steel plate billet; S2. Heat the high manganese steel plate billet, perform asynchronous rolling, and control cooling after rolling to obtain a high manganese steel plate billet; S3. Perform heat treatment on the high manganese steel plate billet to obtain a high manganese steel plate; The asynchronous rolling is asynchronous differential temperature collaborative rolling; During the asynchronous differential temperature collaborative rolling process, asynchronous rolling and differential temperature rolling are carried out simultaneously; During the asynchronous differential temperature collaborative rolling, the speed ratio difference is 1.05 - 1.25, the temperature of the core of the rolled piece > the temperature of the upper and lower surfaces of the rolled piece, the temperatures of the upper and lower surfaces of the rolled piece are equal, and the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20 - 100 °C.

[0007] In the present invention, in step S1, the components are mixed and then smelted and forged. The smelting process can accurately control the composition of the high manganese steel plate to ensure that the content of each element meets the requirements. Combined with the forging process, the internal structure of the high manganese steel plate can be improved, so that it can initially form a cast billet with fewer casting defects, providing a good foundation for subsequent rolling and heat treatment. In step S2, the high manganese steel plate billet is heated and then asynchronous differential temperature cooperative rolling is performed. Then, through the heat treatment process in step S3, the structure and properties of the high manganese steel plate are adjusted, thereby obtaining a high manganese steel plate with good core permeability.

[0008] In the present invention, during asynchronous rolling, the speed ratio of the lower working roll and the upper working roll is 1.05-1.25, for example, it can be 1.05, 1.1, 1.15, 1.2, 1.25, preferably 1.05-1.2, and the upper working roll speed is 1.0 rad·s -1 , the lower working roll speed is 1.05~1.25rad·s -1 , for example, it can be 1.05rad·s -1 , 1.1rad·s -1 , 1.15rad·s -1 , 1.2 rad·s -1 , 1.25rad·s -1 , preferably 1.2 rad·s -1 .

[0009] During differential temperature rolling, the temperature of the core of the rolled piece is greater than the temperature of the upper and lower surfaces of the rolled piece, the temperatures of the upper and lower surfaces of the rolled piece are equal, and the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20~100℃, for example, it can be 20℃, 40℃, 60℃, 80℃, 100℃, preferably 80℃~100℃. When the temperature of the core of the rolled piece is greater than the temperature of the upper and lower surfaces of the rolled piece, the purpose of hard outside and soft inside during the rolling process can be achieved, which is beneficial to increase the rolling permeability of the core.

[0010] As a further technical solution, the upper surface of the rolled piece is the slow roller side, and the lower surface of the rolled piece is the fast roller side.

[0011] As a further technical solution, during the asynchronous temperature differential coordinated rolling, the total reduction rate is 10% to 40%, preferably, the total reduction rate is 30%.

[0012] As a further technical solution, the high manganese steel plate is composed of the following components in weight percentage: C 1.22% - 1.32%, V 0.19% - 0.22%, Mn 18.05% - 18.55%, Cr 0.45% - 0.85%, Ni 0.65% - 0.75%, Si 0.28% - 0.48%, Co 0.1% - 0.15%, B 0.015% - 0.035%, Tb 0.025% - 0.085%, P ≤ 0.018%, S ≤ 0.025%, and the balance is iron and its inevitable impurities.

[0013] In terms of improving the strength performance, currently, it is mainly achieved by regulating the composition, such as adding aluminum and silicon elements. Aluminum can refine austenite grains to achieve fine grain strengthening. However, excessive aluminum will promote the formation of ferrite second phase, leading to cracks. When the amount of silicon element is inappropriate, it will reduce the solubility of carbon in austenite, precipitate carbides, weaken the impact toughness, and it is difficult to precisely control the elements, resulting in limited improvement of the yield strength. In the present invention, the components of the high manganese steel plate include Co, Si, and Tb elements, and the contents of the three are reasonably regulated so that the weight percentage of Co is 0.1% - 0.25%, the weight percentage of Si is 0.28% - 0.48%, and the weight percentage of Tb is 0.025% - 0.085%. Combined with C, V, Mn, Cr, Ni, and B elements, a high manganese steel plate with good yield strength can be obtained. During the current production process of high manganese steel plates, the contents of Co, Si, and Tb elements cannot be accurately controlled within a suitable range, so that the synergistic improvement effect of the three on the yield strength of high manganese steel plates is not prominent. In the present invention, through the common optimization of the organizational structure of high manganese steel plates by these three elements, when the high manganese steel plate bears pressure, it can more effectively resist deformation, thereby effectively improving its yield strength.

[0014] As a further technical solution, the weights of the Co, the Si, and the Tb satisfy the following relationship: 0.5 ≤ (Co + Tb) / Si ≤ 0.75.

[0015] In the present invention, when the weights of Co, Si, and Tb satisfy the following relationship: 0.5 ≤ (Co + Tb) / Si ≤ 0.75, the yield strength of the high manganese steel plate can be further improved, and the yield strength can be increased to 538 - 542 MPa. When the weights of Co, Si, and Tb do not satisfy 0.5 ≤ (Co + Tb) / Si ≤ 0.75, the effect of improving the yield strength of the high manganese steel plate is relatively poor.

[0016] As a further technical solution, the heat treatment sequentially includes a first heat treatment, a second heat treatment, and a third heat treatment; During the first heat treatment, the temperature is raised to 700 - 750 °C at a heating rate of 30 - 50 °C / min and held for 1 - 2 h; During the second heat treatment, the temperature is raised from 700 - 750°C to 970 - 1080°C at a heating rate of 6 - 15°C / min, after holding for 20 - 40 min, it is cooled to room temperature at a cooling rate of 10 - 20°C / min; During the third heat treatment, the temperature is raised to 650 - 710°C at a heating rate of 6 - 15°C / min, after holding for 20 - 30 min, it is cooled to room temperature at a cooling rate of 10 - 20°C / min.

[0017] As a further technical solution, the heating rate of the second heat treatment is greater than that of the third heat treatment.

[0018] In the present invention, the heat treatment is a segmented heat treatment. In the first heat treatment, the temperature is raised to 700 - 750°C at a heating rate of 30 - 50°C / min and held for 1 - 2 h. In this stage, by controlling the appropriate heating rate, heat treatment time, and holding time, the residual stress generated during the previous rolling process of the high manganese steel plate can be effectively eliminated, and the performance stability of the high manganese steel plate is improved; in the second heat treatment, the temperature is raised to a high temperature stage of 970 - 1080°C at a relatively slow heating rate of 6 - 15°C / min. In this high temperature stage, the austenite component in the high manganese steel plate is more uniform, and by reasonably controlling the cooling rate to 10 - 20°C / min, the transformation of austenite into other phases can be inhibited, thereby improving the yield strength of the high manganese steel plate; in the third heat treatment, by adjusting the heating rate, heat treatment temperature, and cooling rate, the residual stress inside the high manganese steel plate can be further eliminated; When the heating rate of the second heat treatment is greater than that of the third heat treatment, the yield strength of the high manganese steel plate can be further improved, and it can be increased to more than 560 MPa. When the heating rate of the second heat treatment is greater than or equal to that of the third heat treatment, the tissue stability inside the high manganese steel plate is relatively poor, thus affecting the improvement of the yield strength of the high manganese steel plate.

[0019] As a further technical solution, the core temperature of the rolled piece is 900°C, and the upper and lower surface temperatures of the rolled piece are both 800 - 880°C, for example, it can be 800°C, 820°C, 840°C, 860°C, 880°C.

[0020] As a further technical solution, the thickness of the high manganese steel plate is 90 - 110 mm, for example, it can be 90 mm, 100 mm, 110 mm, and preferably 100 mm.

[0021] The working principle and beneficial effects of the present invention are as follows: 1. In the present invention, the asynchronous rolling is asynchronous differential temperature co-rolling, where asynchronous rolling and differential temperature rolling are carried out simultaneously. Compared with other asymmetric rolling technologies, asynchronous rolling and differential temperature rolling are easier to implement on existing industrial rolling mills. For asynchronous rolling, only the upper and lower working rolls need to maintain different speeds or a relative roll diameter difference, while the differential temperature rolling process can be achieved by using an ultra-fast cooling technology to control the temperature difference. The combination of asynchronous rolling and differential temperature rolling is beneficial to increasing the core permeability of high manganese steel sheets, improving the shape control ability of the steel sheets, and enhancing the shape quality.

[0022] 2. In the present invention, when the roll speeds of the upper and lower rolls are different and the speed ratio is 1.05 - 1.25, during the rolling process of the rolled piece, the upper and lower surfaces of the rolled piece will be subjected to frictional forces from rolls with different speeds, thereby generating shear deformation inside the rolled piece. While improving the rolling shear force, due to the different degrees of deformation of the upper and lower surfaces, the metal flow inside the rolled piece will become more complex, enabling a greater equivalent strain to be generated in the core, and thus improving the internal tissue structure of the material and enhancing the rolling performance.

[0023] 3. When the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20 - 100 °C, the temperature difference will cause the metal in different parts of the rolled piece to have different plasticity. The core has a higher temperature and better plasticity, making it easier to deform; while the upper and lower surfaces have relatively lower temperatures and relatively more difficult deformation. This plasticity difference will make the equivalent strain in the core more significant during the rolling process. Description of the Drawings

[0024] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0025] Figure 1 It is the equivalent strain diagram distributed along the thickness direction for Example 2, Examples 11 - 14, and Comparative Example 1, that is, the equivalent strain diagram distributed along the thickness direction under different roll speed ratios; Figure 2 It is the equivalent strain diagram distributed along the thickness direction for Example 2, Examples 15 - 18, and Comparative Example 1, that is, the equivalent strain diagram distributed along the thickness direction under different temperature differences; Figure 3 It is the schematic diagram of asynchronous differential temperature co-rolling in Example 2; where, T1 is the core temperature, T2 is the temperature of the upper and lower surfaces of the rolled piece, Ⅰ is the forward slip zone of the asynchronous differential temperature co-rolling deformation zone, Ⅱ is the cross-rolling zone of the asynchronous differential temperature co-rolling deformation zone, Ⅲ is the back slip zone of the asynchronous differential temperature co-rolling deformation zone, R1 is the roll diameter of the upper working roll, R2 is the roll diameter of the lower working roll, n1 is the roll speed of the upper working roll, and n2 is the roll speed of the lower working roll. Specific Embodiments

[0026] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention.

[0027] Embodiment 1 The high manganese steel plate is composed of the following components by weight percentage: C 1.22%, V 0.19%, Mn 18.05%, Cr 0.45%, Ni 0.65%, Si 0.28%, Co 0.1%, B 0.015%, Tb 0.025%, P 0.01%, S 0.01%, and the rest is iron and its inevitable impurities; An asynchronous differential temperature collaborative rolling process for a high manganese steel plate includes the following steps: S1. Mix the components of the high manganese steel plate, smelt, and forge to obtain a high manganese steel plate billet; S2. After heating the high manganese steel plate billet, perform asynchronous rolling and differential temperature rolling, and control the cooling after rolling to obtain a high manganese steel plate billet; wherein, the upper surface of the rolled piece is on the side of the slow roll, and the roll speed is 1.0 rad·s -1 , the lower surface of the rolled piece is on the side of the fast roll, and the roll speed is 1.1 rad·s -1 , control the differential speed ratio of the lower working roll and the upper working roll to be 1.1, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 60 °C, the temperature of the core of the rolled piece is 900 °C, the temperatures of the upper and lower surfaces of the rolled piece are both 840 °C, and control the total reduction ratio to be 10%; S3. Perform the first heat treatment on the high manganese steel plate billet, heat it at a heating rate of 30 °C / min to 700 °C, and hold for 1 h; perform the second heat treatment, heat it from 700 °C to 970 °C at a heating rate of 30 °C / min, hold for 20 min, and then cool it to room temperature at a cooling rate of 10 °C / min; perform the third heat treatment, heat it at a heating rate of 30 °C / min to 650 °C, hold for 20 min, and then cool it to room temperature at a cooling rate of 10 °C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0028] Embodiment 2 The high manganese steel plate is composed of the following components by weight percentage: C 1.27%, V 0.2%, Mn 18.35%, Cr 0.65%, Ni 0.7%, Si 0.3%, Co 0.12%, B 0.03%, Tb 0.03%, P 0.015%, S 0.02%, and the rest is iron and its inevitable impurities; A process for asynchronous differential temperature co-rolling of high manganese steel plates, comprising the following steps: S1. Mix the components of the high manganese steel plate, smelt and forge to obtain a high manganese steel plate billet; S2. After heating the high manganese steel plate billet, perform asynchronous rolling and differential temperature rolling, and control cooling after rolling to obtain a high manganese steel plate billet; wherein, the upper surface of the rolled piece is on the side of the slow roll with a roll speed of 1.0 rad·s -1 and the lower surface of the rolled piece is on the side of the fast roll with a roll speed of 1.1 rad·s -1 Control the speed ratio of the lower working roll to the upper working roll to be 1.1, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece to be 60 °C, the temperature of the core of the rolled piece to be 900 °C, the temperatures of the upper and lower surfaces of the rolled piece to be 840 °C, and control the total reduction ratio to be 30%; S3. Perform the first heat treatment on the high manganese steel plate billet, heat it to 730 °C at a heating rate of 40 °C / min, and hold for 1.5 h; perform the second heat treatment, heat it from 730 °C to 1020 °C at a heating rate of 30 °C / min, hold for 30 min, and then cool it to room temperature at a cooling rate of 15 °C / min; perform the third heat treatment, heat it to 680 °C at a heating rate of 30 °C / min, hold for 25 min, and then cool it to room temperature at a cooling rate of 15 °C / min to obtain a high manganese steel plate with a thickness of 100 mm; Figure 3 is a schematic diagram of the co-rolling of asynchronous rolling and differential temperature rolling in Example 2, that is, a schematic diagram of asynchronous differential temperature co-rolling. Among them, T1 is the core temperature, T2 is the temperature of the upper and lower surfaces of the rolled piece, and the deformation zone of asynchronous differential temperature co-rolling is divided into 3 parts. Ⅰ is the forward slip zone of the asynchronous differential temperature co-rolling deformation zone, Ⅱ is the cross-rolling zone of the asynchronous differential temperature co-rolling deformation zone, and Ⅲ is the backward slip zone of the asynchronous differential temperature co-rolling deformation zone.

[0029] Example 3 The high manganese steel plate is composed of the following components by weight percentage: C 1.32%, V 0.22%, Mn 18.55%, Cr 0.85%, Ni 0.75%, Si 0.48%, Co 0.15%, B 0.035%, Tb 0.085%, P 0.018%, S 0.025%, and the rest is iron and its inevitable impurities; A process for asynchronous differential temperature co-rolling of high manganese steel plates, comprising the following steps: S1. Mix the components of the high manganese steel plate, smelt and forge to obtain a high manganese steel plate billet; S2. After heating the high manganese steel plate billet, perform asynchronous rolling and differential temperature rolling, and control cooling after rolling to obtain a high manganese steel plate billet; wherein, the upper surface of the rolled piece is on the side of the slow roll with a roll speed of 1.0 rad·s -1, the lower surface of the rolled piece is on the side of the fast roll, and the roll speed is 1.1 rad·s -1 , the lower surface of the rolled piece is on the side of the fast roll, the differential speed ratio of the lower working roll and the upper working roll is controlled to be 1.1, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 60 °C, the temperature of the core of the rolled piece is 900 °C, the temperatures of the upper and lower surfaces of the rolled piece are both 840 °C, and the total reduction rate is controlled to be 40%; S3. Perform the first heat treatment on the high manganese steel slab, heat it up to 750 °C at a heating rate of 50 °C / min, and hold for 2 h; perform the second heat treatment, heat it from 750 °C to 1080 °C at a heating rate of 30 °C / min, hold for 40 min, and then cool it to room temperature at a cooling rate of 20 °C / min; perform the third heat treatment, heat it up to 710 °C at a heating rate of 30 °C / min, hold for 30 min, and then cool it to room temperature at a cooling rate of 20 °C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0030] Example 4 The difference between this example and Example 2 is only that, in this example, the weight percentage of Si added is 0.28%, the weight percentage of Co added is 0.1%, and the weight percentage of Tb added is 0.025%.

[0031] Example 5 The difference between this example and Example 2 is only that, in this example, the weight percentage of Si added is 0.28%, the weight percentage of Co added is 0.14%, and the weight percentage of Tb added is 0.07%.

[0032] Example 6 The difference between this example and Example 2 is only that, in this example, the weight percentage of Si added is 0.28%, the weight percentage of Co added is 0.148%, and the weight percentage of Tb added is 0.076%.

[0033] Example 7 The difference between this example and Example 2 is only that the step S3 in the asynchronous differential temperature co-rolling process of the high manganese steel plate in this example is different, specifically: S3. Perform the first heat treatment on the high manganese steel slab, heat it up to 730 °C at a heating rate of 40 °C / min, and hold for 1.5 h; perform the second heat treatment, heat it from 730 °C to 1020 °C at a heating rate of 3 °C / min, hold for 30 min, and then cool it to room temperature at a cooling rate of 15 °C / min; perform the third heat treatment, heat it up to 680 °C at a heating rate of 3 °C / min, hold for 25 min, and then cool it to room temperature at a cooling rate of 15 °C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0034] Example 8 The difference between this embodiment and Embodiment 2 is only that step S3 in the asynchronous differential temperature collaborative rolling process of the high manganese steel plate in this embodiment is different. Specifically: S3. Perform the first heat treatment on the high manganese steel plate billet, raise the temperature to 730°C at a heating rate of 40°C / min, and hold for 1.5 h; perform the second heat treatment, raise the temperature from 730°C to 1020°C at a heating rate of 6°C / min, hold for 30 min, and then cool to room temperature at a cooling rate of 15°C / min; perform the third heat treatment, raise the temperature to 680°C at a heating rate of 15°C / min, hold for 25 min, and then cool to room temperature at a cooling rate of 15°C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0035] Embodiment 9 The difference between this embodiment and Embodiment 2 is only that step S3 in the asynchronous differential temperature collaborative rolling process of the high manganese steel plate in this embodiment is different. Specifically: S3. Perform the first heat treatment on the high manganese steel plate billet, raise the temperature to 730°C at a heating rate of 40°C / min, and hold for 1.5 h; perform the second heat treatment, raise the temperature from 730°C to 1020°C at a heating rate of 15°C / min, hold for 30 min, and then cool to room temperature at a cooling rate of 15°C / min; perform the third heat treatment, raise the temperature to 680°C at a heating rate of 15°C / min, hold for 25 min, and then cool to room temperature at a cooling rate of 6°C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0036] Embodiment 10 The difference between this embodiment and Embodiment 2 is only that step S3 in the asynchronous differential temperature collaborative rolling process of the high manganese steel plate in this embodiment is different. Specifically: S3. Perform the first heat treatment on the high manganese steel plate billet, raise the temperature to 730°C at a heating rate of 40°C / min, and hold for 1.5 h; perform the second heat treatment, raise the temperature from 730°C to 1020°C at a heating rate of 15°C / min, hold for 30 min, and then cool to room temperature at a cooling rate of 15°C / min; perform the third heat treatment, raise the temperature to 680°C at a heating rate of 6°C / min, hold for 25 min, and then cool to room temperature at a cooling rate of 6°C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0037] Embodiment 11 The difference between this embodiment and Embodiment 2 is only that in this embodiment, the upper surface of the rolled piece is on the slow roll side with a roll speed of 1.0 rad·s -1 , and the lower surface of the rolled piece is on the fast roll side with a roll speed of 1.05 rad·s -1 , and control the differential speed ratio of the lower working roll and the upper working roll to be 1.05.

[0038] Example 12 The difference between this example and Example 2 is only that in this example, the upper surface of the rolled piece is on the side of the slow roller with a roller speed of 1.0 rad·s -1 , and the lower surface of the rolled piece is on the side of the fast roller with a roller speed of 1.15 rad·s -1 , and the differential speed ratio of the lower working roll and the upper working roll is controlled to be 1.15.

[0039] Example 13 The difference between this example and Example 2 is only that in this example, the upper surface of the rolled piece is on the side of the slow roller with a roller speed of 1.0 rad·s -1 , and the lower surface of the rolled piece is on the side of the fast roller with a roller speed of 1.2 rad·s -1 , and the differential speed ratio of the lower working roll and the upper working roll is controlled to be 1.2.

[0040] Example 14 The difference between this example and Example 2 is only that in this example, the upper surface of the rolled piece is on the side of the slow roller with a roller speed of 1.0 rad·s -1 , and the lower surface of the rolled piece is on the side of the fast roller with a roller speed of 1.25 rad·s -1 , and the differential speed ratio of the lower working roll and the upper working roll is controlled to be 1.25.

[0041] Example 15 The difference between this example and Example 2 is only that in this example, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20 °C, the temperature of the core of the rolled piece is 900 °C, and the temperatures of the upper and lower surfaces of the rolled piece are both 880 °C.

[0042] Example 16 The difference between this example and Example 2 is only that in this example, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 40 °C, the temperature of the core of the rolled piece is 900 °C, and the temperatures of the upper and lower surfaces of the rolled piece are both 860 °C.

[0043] Example 17 The difference between this example and Example 2 is only that in this example, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 80 °C, the temperature of the core of the rolled piece is 900 °C, and the temperatures of the upper and lower surfaces of the rolled piece are both 820 °C.

[0044] Example 18 The difference between this example and Example 2 is only that in this example, the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 100 °C, the temperature of the core of the rolled piece is 900 °C, and the temperatures of the upper and lower surfaces of the rolled piece are both 800 °C.

[0045] Example 19 The difference between this example and Example 2 is only that in this example, Tb is not added.

[0046] Example 20 The difference between this example and Example 2 is only that Co is not added in this example.

[0047] Example 21 The difference between this example and Example 2 is only that Si is not added in this example.

[0048] Example 22 The difference between this example and Example 2 is only that neither Si, Co nor Tb is added in this example.

[0049] Example 23 The difference between this example and Example 2 is only that step S3 in the asynchronous differential temperature co-rolling process of the high manganese steel plate in this example is different. Specifically: S3. Perform the first heat treatment on the high manganese steel plate billet, heat it up to 730°C at a heating rate of 40°C / min, and hold for 1.5 h; perform the second heat treatment, heat it from 730°C to 1020°C at a heating rate of 6°C / min, after holding for 30 min, cool it to room temperature at a cooling rate of 15°C / min; perform the third heat treatment, heat it up to 680°C at a heating rate of 6°C / min, after holding for 25 min, cool it to room temperature at a cooling rate of 6°C / min to obtain a high manganese steel plate with a thickness of 100 mm.

[0050] Comparative Example 1 The difference between this comparative example and Example 2 is only that step S2 in the asynchronous differential temperature co-rolling process of the high manganese steel plate in this comparative example is different. Specifically: S2. After heating the high manganese steel plate billet, perform synchronous and differential temperature rolling, and perform controlled cooling after rolling to obtain a high manganese steel plate billet; among them, the roll speeds of the upper surface and the lower surface of the rolled piece are the same, and the roll speed is 1.0 rad·s -1 , there is no temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece, the temperature of the core of the rolled piece is 900°C, the temperatures of the upper and lower surfaces of the rolled piece are both 900°C, and the total reduction rate is controlled at 30%.

[0051] Experimental Example 1 The high manganese steel plates prepared in Examples 1 to 10 and Examples 19 to 23 were tested for yield strength according to the test method in GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", and the test speed was 0.002 s -1 , and the test results were the average values of 5 specimens. The test results are shown in Table 1 below: Table 1 Yield strength test results of Examples 1 to 10 and Examples 19 to 23

[0052] Compared with Examples 19 to 22, the yield strength of the high manganese steel plates prepared in Examples 1 to 10 and Example 23 is improved, indicating that the high manganese steel plates prepared in this scheme have good yield strength, and the yield strength can be increased to above 519 MPa.

[0053] Experimental Example 2 The high manganese steel plates prepared in Example 2, Examples 11 to 18, and Comparative Example 1 were subjected to equivalent strain tests along the thickness direction under different roller speed ratios and different temperature differences. The test results are as follows: Figures 1 - 2 shown.

[0054] Result analysis: Figure 1 The equivalent strain diagrams along the thickness direction of Example 2, Examples 11 to 14, and Comparative Example 5 are, that is, the equivalent strain diagrams along the thickness direction under different roller speed ratios. Figure 2 These are equivalent strain diagrams distributed along the thickness direction of Example 2, Examples 15 to 18, and Comparative Example 5, that is, equivalent strain diagrams distributed along the thickness direction under different temperature differences.

[0055] When the horizontal axis is 0mm, the rolled piece is close to the slow roller side, and when the horizontal axis is 100mm, the rolled piece is close to the fast roller side. Figure 1 and Figure 2 It can be seen that the equivalent strain on the fast roller side is greater than that on the slow roller side. This is because the metal flow speed of the rolled piece driven by the fast roller side is faster, resulting in a greater deformation. Figure 1 In the figure, the roll speed ratio of 1.05~1.25 is compared with the synchronous rolling core increase. As the roll speed ratio increases, the core increase gradually increases, increasing by 3.53%, 8.55%, 12.8%, 17.4% and 19.6% respectively. This shows that increasing the speed ratio is beneficial to increasing the permeability of the rolled core. Figure 2 The core permeability increases at a temperature difference of 20°C to 100°C compared to synchronous rolling. As the temperature difference increases, the core permeability increases, first decreasing, then increasing, and finally decreasing, increasing by 7.48%, 5.58%, 8.55%, 9.22%, and 8.92%, respectively. The core equivalent strain increase is smallest at a temperature difference of 40°C, while it is largest at a temperature difference of 80°C. This indicates that selecting an appropriate temperature difference is beneficial for increasing the permeability of the rolled core. It also indicates that the length of the rolling zone is the primary factor affecting the permeability of the rolled core. To ensure the permeability of the rolled core, the process parameters should be selected to maximize the length of the rolling zone.

[0056] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An asynchronous differential temperature collaborative rolling process for high manganese steel plates, characterized in that, It includes the following steps: S1. Mix the components of the high manganese steel plate, smelt and forge to obtain a high manganese steel plate billet; S2. Heat the high manganese steel plate billet, perform asynchronous rolling, and control cooling after rolling to obtain a high manganese steel plate billet; S3. Heat-treat the high manganese steel plate billet to obtain a high manganese steel plate; The asynchronous rolling is asynchronous differential temperature collaborative rolling; During the asynchronous differential temperature collaborative rolling process, asynchronous rolling and differential temperature rolling are carried out simultaneously; During the asynchronous differential temperature collaborative rolling, the asynchronous speed ratio is 1.05 - 1.25, the temperature of the core of the rolled piece > the temperatures of the upper and lower surfaces of the rolled piece, the temperatures of the upper and lower surfaces of the rolled piece are equal, and the temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 20 - 100°C.

2. The asynchronous differential temperature collaborative rolling process of a high manganese steel plate according to claim 1, characterized in that, The asynchronous speed ratio is 1.05 - 1.

2.

3. A asynchronous differential temperature collaborative rolling process for high manganese steel plates according to claim 1, characterized in that, The temperature difference between the core of the rolled piece and the upper and lower surfaces of the rolled piece is 80 - 100°C.

4. A process for asynchronous differential temperature collaborative rolling of high manganese steel plates according to claim 1, characterized in that, During the asynchronous differential temperature collaborative rolling, the total reduction ratio is 10% - 40%, preferably 30%.

5. A asynchronous differential temperature collaborative rolling process for high manganese steel plates according to claim 1, characterized in that, The high manganese steel plate is composed of the following components by weight percentage: C 1.22% - 1.32%, V 0.19% - 0.22%, Mn 18.05% - 18.55%, Cr 0.45% - 0.85%, Ni 0.65% - 0.75%, Si 0.28% - 0.48%, Co 0.1% - 0.15%, B 0.015% - 0.035%, Tb 0.025% - 0.085%, P ≤ 0.018%, S ≤ 0.025%, and the balance is iron and its inevitable impurities.

6. A process for asynchronous differential temperature collaborative rolling of high manganese steel plates according to claim 5, characterized in that, The weights of Co, Si, and Tb satisfy the following relationship: 0.5 ≤ (Co + Tb) / Si ≤ 0.

75.

7. A asynchronous differential temperature collaborative rolling process for high manganese steel plates according to claim 1, characterized in that, The heat treatment sequentially includes a first heat treatment, a second heat treatment, and a third heat treatment; During the first heat treatment, heat up at a heating rate of 30 - 50°C / min to 700 - 750°C and hold for 1 - 2 h; During the second heat treatment, heat up from 700 - 750°C to 970 - 1080°C at a heating rate of 6 - 15°C / min, hold for 20 - 40 min, and then cool to room temperature at a cooling rate of 10 - 20°C / min; During the third heat treatment, heat up to 650 - 710°C at a heating rate of 6 - 15°C / min, hold for 20 - 30 min, and then cool to room temperature at a cooling rate of 10 - 20°C / min.

8. A asynchronous differential temperature collaborative rolling process for high manganese steel plates, characterized in that, The heating rate of the second heat treatment is greater than that of the third heat treatment.

9. A process for asynchronous differential temperature collaborative rolling of high manganese steel plates according to claim 1, characterized in that, The temperature of the core of the rolled piece is 900°C, and the temperatures of the upper and lower surfaces of the rolled piece are both 800 - 880°C.

10. A asynchronous differential temperature collaborative rolling process for high manganese steel plates according to claim 1, characterized in that, The thickness of the high manganese steel plate is 90 - 110 mm.

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