Processing method of high manganese steel heads

Abstract

This application provides a processing method for high-manganese steel heads, comprising: cold-blow molding high-manganese steel sheets to obtain a bowl-shaped blank, wherein the blowing pressure of the cold-blow molding process is 12MPa-20MPa, and the duration is 4h-8h; heating the bowl-shaped blank to obtain a preheated blank; and warm spinning the preheated blank to obtain the high-manganese steel head. The processing of the high-manganese steel sheets achieves uniform deformation, and the bowl-shaped blank is kept at a certain temperature before and during the warm spinning process to avoid temperature drop, thereby reducing the occurrence of head cracking, lowering the scrap rate of the heads, improving economic efficiency, and reducing overall production costs.

Description

Technical Field

[0001] This application relates to the field of head processing, and more particularly to a processing method for high manganese steel heads. Background Technology

[0002] Heads can be classified into different shapes such as hemispherical, elliptical, and butterfly, and are among the more complex components to be formed in pressure vessels.

[0003] When processing end caps, using high-manganese steel instead of stainless steel not only satisfies the low-temperature resistance of stainless steel but also improves its strength, which helps to achieve lightweight end caps and reduces the cost of the stainless steel deformation hardening process.

[0004] However, high manganese steel is prone to cracking when used as a material for end caps, resulting in a high scrap rate, which increases production costs and reduces economic benefits. Summary of the Invention

[0005] This application provides a processing method for high manganese steel heads to solve the problem in related technologies that high manganese steel is prone to cracking when used as a head processing material, resulting in a high scrap rate of heads, which increases production costs and reduces economic benefits.

[0006] This application provides a method for processing high-manganese steel heads, including the following steps:

[0007] High manganese steel sheets are subjected to cold drum treatment to obtain a bowl-shaped blank. The drum pressure of the cold drum treatment is 12MPa-20MPa and the duration is 4h-8h.

[0008] The bowl-shaped blank is heated to obtain a preheated blank;

[0009] The preheated blank is subjected to warm spinning treatment to obtain a high-manganese steel head.

[0010] According to an embodiment of this application, a high-manganese steel sheet is subjected to cold drum forming to obtain a bowl-shaped blank, comprising:

[0011] The high-manganese steel sheet is subjected to the first cold drum treatment using the first die head;

[0012] A second die head is used to perform a second cold drum treatment on the high manganese steel sheet that has completed the first cold drum treatment, resulting in a bowl-shaped blank. The diameter of the first die head is larger than the diameter of the second die head.

[0013] According to an embodiment of this application, a bowl-shaped blank is heated to obtain a preheated blank, comprising:

[0014] The bowl-shaped blank is fed into the heating furnace, and the furnace temperature is controlled within the first preset temperature range.

[0015] The heating furnace is kept warm to obtain a preheated blank.

[0016] According to an embodiment of this application, a high-manganese steel head is obtained by hot spinning a preheated blank, comprising:

[0017] Under the condition that the processing temperature is controlled within the second preset temperature range, the preheated blank is subjected to warm spinning treatment to obtain a high manganese steel end cap.

[0018] According to an embodiment of this application, the high-manganese steel sheet contains 0-2 weld seams. Before performing cold blasting treatment on the high-manganese steel sheet, the method further includes:

[0019] Weld defects are detected in high-manganese steel sheets, and high-manganese steel sheets with weld defects are identified as unprocessable sheets. Weld defects include one or more of the following: weld porosity, weld voids, and weld bubbles.

[0020] According to an embodiment of this application, before heat treatment of the bowl-shaped blank, the method further includes:

[0021] Weld anti-slip blocks to the bottom outer surface of the bowl-shaped blank;

[0022] When a high-manganese steel sheet contains at least one weld, a crack-resistant block is welded at the location of the weld in the end region of the bowl-shaped blank.

[0023] According to an embodiment of this application, the diameter of the first mold head is 1350mm-1450mm.

[0024] According to an embodiment of this application, the diameter of the second mold head is 1200mm-1300mm.

[0025] According to an embodiment of this application, the duration of the first cold drumming process is 2h-5h.

[0026] According to an embodiment of this application, the duration of the second cold drumming process is 2-3 hours.

[0027] According to an embodiment of this application, the first preset temperature range is 250℃-450℃.

[0028] According to an embodiment of this application, the heat preservation treatment time is 12-15 minutes.

[0029] According to an embodiment of this application, the second preset temperature range is 250°C-400°C.

[0030] According to the embodiments of this application, the Mn content of the high manganese steel sheet is 22%-26%.

[0031] According to the embodiments of this application, the yield strength of the high manganese steel sheet is 400MPa-550MPa.

[0032] According to the embodiments of this application, the tensile strength of the high manganese steel sheet is 800MPa-950MPa.

[0033] According to embodiments of this application, the elongation of the high-manganese steel sheet is 35%-65%.

[0034] According to the embodiments of this application, the Charpy impact energy (KV) of high manganese steel sheet at -196°C is 60J-300J.

[0035] This application achieves the following technical effects by obtaining high-manganese steel sheets; subjecting the high-manganese steel sheets to cold drum treatment to obtain a bowl-shaped blank, wherein the drum pressure of the cold drum treatment is 12MPa-20MPa and the duration is 4h-8h; subsequently, the bowl-shaped blank is heated to obtain a preheated blank; and finally, the preheated blank is warm-spinning to obtain a high-manganese steel end cap.

[0036] In the processing of high manganese steel heads, cold drumming treatment of the high manganese steel sheet can avoid cracking caused by the instantaneous high stress generated during one-time cold stamping by forming multiple drums. On this basis, by setting the drumming pressure of cold drumming treatment to 12MPa-20MPa and the duration to 4h-8h, the stress on the material during each drumming can be reduced, thereby achieving uniform deformation of the high manganese steel sheet and further reducing the occurrence of cracking.

[0037] Preheating the bowl-shaped blank before the warm spinning process can reduce the material's resistance to deformation and help maintain a certain temperature before entering the subsequent warm spinning process, thus avoiding temperature drop and further reducing the occurrence of cracking.

[0038] Based on this, warm spinning treatment of the bowl-shaped blank can also maintain a certain temperature of the end cap during the spinning process, avoiding temperature drop and cracking of the end cap during the spinning process, and further reducing the occurrence of cracking.

[0039] Overall, the processing method for high-manganese steel heads provided in this application achieves uniform deformation of the high-manganese steel sheet during processing, and maintains a certain temperature for the bowl-shaped blank before and during the warm spinning process to avoid temperature drop, thereby reducing the occurrence of head cracking, lowering the scrap rate of the heads, improving economic efficiency, and reducing overall production costs. Attached Figure Description

[0040] 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.

[0041] Figure 1 This is a flowchart of the processing method for the high manganese steel head provided in this application.

[0042] Figure 2 This is a schematic cross-sectional view of the high-manganese steel head prepared in Example 1 of this application.

[0043] Figure 3 This is a schematic diagram of the overall shape of the high-manganese steel head prepared in Example 1 of this application.

[0044] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0045] The various embodiments or implementation schemes in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0048] Bake-hardening steel is a type of steel that undergoes a process called bake-hardening, which makes it stronger and more resilient than other types of high-strength steel. This unique quality makes bake-hardening steel a popular choice in the automotive industry for parts such as body panels, doors, and hoods, due to its superior resistance to dents and deformation.

[0049] Heads can be classified into different shapes such as hemispherical, elliptical, and butterfly, and are among the more complex components to be formed in pressure vessels. This is especially true for heads with a diameter ≥3200mm. Integral stamping under uniform internal pressure is quite difficult; if a segmented stamping method is used, the amount of welding work required for assembly is also substantial.

[0050] Lightweighting is a trend in various industries. When processing end caps, using high manganese steel instead of stainless steel can improve the low-temperature resistance and wear resistance of the end caps and help achieve lightweighting. For example, using high manganese steel with a strength of ≥800MPa can achieve a weight reduction of more than 15% compared to using stainless steel. Using high manganese steel instead of stainless steel can also reduce the cost of the stainless steel deformation hardening process.

[0051] However, high manganese steel is prone to cracking when used as a material for end caps, resulting in a high scrap rate, which increases production costs and reduces economic benefits.

[0052] In view of the above problems, this application provides a processing method for high manganese steel heads, which can reduce the occurrence of cracking, reduce the production cost of high manganese steel heads, and reduce the scrap rate of high manganese steel heads.

[0053] This application provides a method for processing high-manganese steel heads. Please refer to [link / reference]. Figure 1 It includes the following steps:

[0054] S100: Cold drum treatment is performed on high manganese steel sheets to obtain a bowl-shaped blank. The drum pressure of the cold drum treatment is 12MPa-20MPa and the duration is 4h-8h.

[0055] S200: Heat the bowl-shaped blank to obtain a preheated blank;

[0056] S300: The preheated blank is subjected to warm spinning treatment to obtain a high manganese steel head.

[0057] In the processing of high manganese steel heads, cold drumming treatment of the high manganese steel sheet can avoid cracking caused by the instantaneous high stress generated during one-time cold stamping by forming multiple drums. On this basis, by setting the drumming pressure of cold drumming treatment to 12MPa-20MPa and the duration to 4h-8h, the stress on the material during each drumming can be reduced, thereby achieving uniform deformation of the high manganese steel sheet and further reducing the occurrence of cracking.

[0058] Preheating the bowl-shaped blank before the warm spinning process can reduce the material's resistance to deformation and help maintain a certain temperature before entering the subsequent warm spinning process, thus avoiding temperature drop and further reducing the occurrence of cracking.

[0059] Based on this, warm spinning treatment of the bowl-shaped blank can also maintain a certain temperature of the end cap during the spinning process, avoiding temperature drop and cracking of the end cap during the spinning process, and further reducing the occurrence of cracking.

[0060] The specific steps for S100 are as follows:

[0061] High manganese steel sheets are subjected to cold drum treatment to obtain a bowl-shaped blank. The drum pressure of the cold drum treatment is 12MPa-20MPa and the duration is 4h-8h.

[0062] In the processing of high manganese steel heads, cold drumming treatment of the high manganese steel sheet can avoid cracking caused by the instantaneous high stress generated during one-time cold stamping by forming multiple drums. On this basis, by setting the drumming pressure of cold drumming treatment to 12MPa-20MPa and the duration to 4h-8h, the stress on the material during each drumming can be reduced, thereby achieving uniform deformation of the high manganese steel sheet and further reducing the occurrence of cracking.

[0063] In some embodiments, the high-manganese steel sheet is subjected to cold drum forming to obtain a bowl-shaped blank, including:

[0064] The high-manganese steel sheet is subjected to the first cold drum treatment using the first die head;

[0065] A second die head is used to perform a second cold drum treatment on the high manganese steel sheet that has completed the first cold drum treatment, resulting in a bowl-shaped blank. The diameter of the first die head is larger than the diameter of the second die head.

[0066] In this embodiment, a first die with a larger diameter is first used to perform a first cold drum treatment on the high manganese steel sheet. This can gradually introduce an initial curvature into the flat high manganese steel sheet, and the use of a first die with a larger diameter reduces the stress on the material in the early stage of drum forming, avoiding one-time deep deformation of the high manganese steel sheet, thereby reducing the occurrence of cracking.

[0067] The S200 steps are as follows: The bowl-shaped blank is heated to obtain a preheated blank;

[0068] Preheating the bowl-shaped blank before warm spinning can reduce the material's resistance to deformation and help maintain a certain temperature before entering the subsequent warm spinning process, thus avoiding temperature drop and further reducing the occurrence of cracking.

[0069] In some embodiments, the bowl-shaped blank is heated to obtain a preheated blank, including:

[0070] The bowl-shaped blank is fed into the heating furnace, and the furnace temperature is controlled within the first preset temperature range.

[0071] The heating furnace is kept warm to obtain a preheated blank.

[0072] In practical applications, the bowl-shaped blank can be fed into a heating furnace and the furnace temperature can be controlled to heat the blank. Heating can reduce the deformation resistance of the material and help maintain the bowl-shaped blank at a certain temperature before entering the subsequent hot spinning process, thus avoiding temperature drop and reducing cracking.

[0073] Based on this, by sending the bowl-shaped blank into the heating furnace and controlling the furnace to maintain the temperature for a period of time, it is helpful to achieve full heating of the bowl-shaped blank and ensure that the bowl-shaped blank is heated evenly as a whole, thus preventing cracking caused by local temperature differences within the bowl-shaped blank.

[0074] The S300 process is as follows: The preheated blank is subjected to warm spinning treatment to obtain a high-manganese steel head.

[0075] Warm spinning treatment of the bowl-shaped blank can maintain a certain temperature of the end cap during the spinning process, avoiding temperature drop and cracking, and further reducing the occurrence of cracking.

[0076] In some embodiments, a preheated blank is subjected to hot spinning treatment to obtain a high-manganese steel head, including:

[0077] Under the condition that the processing temperature is controlled within the second preset temperature range, the preheated blank is subjected to warm spinning treatment to obtain a high manganese steel end cap.

[0078] Warm spinning of preheated blanks within a certain processing temperature range can maintain a certain temperature of the end cap during spinning, preventing temperature drop and cracking, and further reducing the occurrence of cracking.

[0079] In some embodiments, the high-manganese steel sheet contains 0-2 weld seams, and the method further includes, before performing cold blasting treatment on the high-manganese steel sheet:

[0080] Weld defects are detected in high-manganese steel sheets, and high-manganese steel sheets with weld defects are identified as unprocessable sheets. Weld defects include one or more of the following: weld porosity, weld voids, and weld bubbles.

[0081] In practical applications, considering the actual diameter requirements of the end cap, the high manganese steel sheet can contain 0-2 welds. The welds can be distributed in the central area or both sides of the high manganese steel sheet. However, before processing the high manganese steel sheet, weld defects should be detected by ultrasonic testing or other methods to eliminate high manganese steel sheets with weld defects, thereby avoiding weld cracking during processing.

[0082] Weld defects generally include one or more of the following: weld porosity, weld voids, and weld bubbles. The area where the weld is located usually becomes one of the stress concentration areas during the processing of high manganese steel heads. If the high manganese steel sheet has at least one of the above-mentioned weld defects, it will increase the possibility of weld cracking during processing. However, by detecting weld defects in high manganese steel sheets through methods such as ultrasonic testing, high manganese steel sheets with weld defects can be eliminated in advance, thereby improving the quality stability of high manganese steel heads.

[0083] In some embodiments, before heat treatment of the bowl-shaped blank, the method further includes:

[0084] Weld anti-slip blocks to the bottom outer surface of the bowl-shaped blank;

[0085] When a high-manganese steel sheet contains at least one weld, a crack-resistant block is welded at the location of the weld in the end region of the bowl-shaped blank.

[0086] In practical applications, in order to prevent the bowl-shaped blank from slipping during the spinning process, anti-slip blocks can be welded to the bottom outer surface of the bowl-shaped blank, thereby improving the stress stability of the bowl-shaped blank during the spinning process.

[0087] When the high manganese steel sheet contains at least one weld, anti-crack blocks can be welded at the location of the weld in the end area of ​​the bowl-shaped blank. The anti-crack blocks can distribute the stress on the weld during processing and effectively prevent the weld from cracking.

[0088] In some embodiments, the diameter of the first mold head is 1350mm-1450mm.

[0089] In some embodiments, the diameter of the second mold head is 1200mm-1300mm.

[0090] The diameter of the first die head is controlled at 1350mm-1450mm, and the diameter of the second die head is controlled at 1200mm-1300mm. This allows for effective control of the forming depth during different cold forming stages using dies of different radii, enabling a gradual transition from flat to deep arc in the high-manganese steel sheet.

[0091] In some embodiments, the duration of the first cold drumming process is 2h-5h.

[0092] In some embodiments, the duration of the second cold drumming process is 2-3 hours.

[0093] In some embodiments, the first preset temperature range is 250°C-450°C.

[0094] In some embodiments, the heat preservation treatment time is 12-15 minutes.

[0095] The first preset temperature range is controlled between 250℃ and 450℃. This can avoid both excessively high furnace temperature, which would waste resources, and excessively low furnace temperature, which would prevent the bowl-shaped blank from being fully heated to the appropriate temperature. This would lead to defects such as cold cracks due to temperature drop during hot spinning, thus affecting the quality of the finished head.

[0096] Based on this, setting the heat preservation time to 12-15 minutes helps to fully heat the bowl-shaped blank and ensure that the bowl-shaped blank is heated evenly, avoiding overheating of the surface or underheating of the center, thereby preventing cracking of the bowl-shaped blank due to local temperature differences.

[0097] In some embodiments, the second preset temperature range is 250°C-400°C.

[0098] The second preset temperature range is controlled at 250℃-400℃. This, combined with the setting of the first preset temperature range, can prevent defects such as cold cracks from occurring in the bowl-shaped blank during the hot spinning process due to temperature drop, thereby affecting the quality of the finished end cap.

[0099] In some embodiments, the Mn content of the high-manganese steel sheet is 22%-26%.

[0100] In some embodiments, the yield strength of the high-manganese steel sheet is 400MPa-550MPa.

[0101] In some embodiments, the tensile strength of the high-manganese steel sheet is 800MPa-950MPa.

[0102] In some embodiments, the elongation of the high manganese steel sheet is 35%-65%.

[0103] In some embodiments, the Charpy impact energy (KV) of the high-manganese steel sheet at -196°C is 60J-300J.

[0104] Controlling the chemical composition and mechanical properties of high-manganese steel within the aforementioned range helps to leverage the advantages of high-manganese steel sheets in terms of mechanical properties during processing. This results in high-manganese steel heads that simultaneously possess both high strength and high toughness, while maintaining excellent impact resistance and safety performance even at ultra-low temperatures of -196℃.

[0105] Bake-hardening steel is a type of steel that undergoes a process called bake-hardening, which makes it stronger and more resilient than other types of high-strength steel. This unique quality makes bake-hardening steel a popular choice in the automotive industry for parts such as body panels, doors, and hoods, due to its superior resistance to dents and deformation.

[0106] Heads can be classified into different shapes such as hemispherical, elliptical, and butterfly, and are among the more complex components to be formed in pressure vessels. This is especially true for heads with a diameter ≥3200mm. Integral stamping under uniform internal pressure is quite difficult; if a segmented stamping method is used, the amount of welding work required for assembly is also substantial.

[0107] Lightweighting is a trend in various industries. When processing end caps, using high manganese steel instead of stainless steel can improve the low-temperature resistance and wear resistance of the end caps and help achieve lightweighting. For example, using high manganese steel with a strength of ≥800MPa can achieve a weight reduction of more than 15% compared to using stainless steel. Using high manganese steel instead of stainless steel can also reduce the cost of the stainless steel deformation hardening process.

[0108] However, high manganese steel is prone to cracking when used as a material for end caps, resulting in a high scrap rate, which increases production costs and reduces economic benefits.

[0109] In the processing of high manganese steel heads, this application employs a cold-drumming process on the high manganese steel sheet. This allows for multiple drumming stages, avoiding the cracking caused by the instantaneous high stress generated during single-stage cold stamping. Furthermore, by setting the drumming pressure to 12MPa-20MPa and the duration to 4-8 hours, the stress on the material during each drumming stage is reduced, thereby achieving uniform deformation of the high manganese steel sheet and further minimizing the occurrence of cracking.

[0110] Preheating the bowl-shaped blank before the warm spinning process can reduce the material's resistance to deformation and help maintain a certain temperature before entering the subsequent warm spinning process, thus avoiding temperature drop and further reducing the occurrence of cracking.

[0111] Based on this, warm spinning treatment of the bowl-shaped blank can also maintain a certain temperature of the end cap during the spinning process, avoiding temperature drop and cracking of the end cap during the spinning process, and further reducing the occurrence of cracking.

[0112] Example

[0113] The following embodiments describe the disclosure of this application in more detail. These embodiments are for illustrative purposes only, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0114] Example 1:

[0115] The high-manganese steel sheet has a Mn content of 23.826%, a yield strength of 528 MPa, a tensile strength of 912 MPa, an elongation of 39%, an average impact energy of 204.7 J at -196℃, and a thickness of 14.0 mm.

[0116] The high-manganese steel sheet is a circular sheet with a diameter of 3700mm. There is a weld seam in the center of the circular sheet. The diameter of the finished head is 3000mm.

[0117] S1: The drumming machine uses a pressure of 16MPa to perform cold drumming on the high manganese steel sheet. First, a first die head with a diameter of 1450mm is used for the first cold drumming treatment, which lasts for 3.5 hours. Then, a second die head with a diameter of 1300mm is used for the second cold drumming treatment, which lasts for 2.5 hours. The total drumming treatment time is 6 hours, resulting in a bowl-shaped blank.

[0118] S2: Weld 4 anti-slip blocks to the bottom outer surface of the bowl-shaped blank, and weld anti-crack blocks at the location of the weld seam in the end area of ​​the bowl-shaped blank.

[0119] S3: The bowl-shaped blank is sent into the heating furnace. The furnace temperature is controlled at 400℃ and held for 15 minutes to obtain the preheated blank.

[0120] S4: Under the condition of processing temperature controlled at 350℃, the preheated blank is warm-spun to a diameter of 3000mm to obtain a high manganese steel end cap.

[0121] S5: Remove the anti-slip blocks and anti-crack blocks from the high manganese steel head, and grind the local surface of the high manganese steel head.

[0122] The high-manganese steel head obtained in this embodiment meets the design requirements of the drawings, and no microcracks visible to the naked eye appear on the surface, and the weld flaw detection shows no defects.

[0123] Example 2:

[0124] The high-manganese steel sheet has a Mn content of 23.663%, a yield strength of 487 MPa, a tensile strength of 918 MPa, an elongation of 47%, an average impact energy of 205.7 J at -196℃, and a thickness of 12.0 mm.

[0125] The high-manganese steel sheet is a circular sheet with a diameter of 3100mm. The circular sheet has two weld seams, and the finished head has a diameter of 2600mm.

[0126] S1: The drumming machine uses a pressure of 14MPa to perform cold drumming on the high manganese steel sheet. First, a first die head with a diameter of 1400mm is used for the first cold drumming treatment, which takes 3.2 hours. Then, a second die head with a diameter of 1280mm is used for the second cold drumming treatment, which takes 2.3 hours. The total drumming time is 5.5 hours, resulting in a bowl-shaped blank.

[0127] S2: Weld 4 anti-slip blocks to the bottom outer surface of the bowl-shaped blank, and weld anti-crack blocks at the location of each weld in the end area of ​​the bowl-shaped blank.

[0128] S3: The bowl-shaped blank is sent into the heating furnace. The furnace temperature is controlled at 300℃ and held for 13 minutes to obtain the preheated blank.

[0129] S4: Under the condition of processing temperature controlled at 250℃, the preheated blank is warm-spun to a diameter of 2600mm to obtain a high manganese steel end cap.

[0130] S5: Remove the anti-slip blocks and anti-crack blocks from the high manganese steel head, and grind the local surface of the high manganese steel head.

[0131] The high-manganese steel head obtained in this embodiment meets the design requirements of the drawings, and no microcracks visible to the naked eye appear on the surface, and the weld flaw detection shows no defects.

[0132] Comparative Example 1:

[0133] The high-manganese steel sheet has a Mn content of 22.46%, a yield strength of 428 MPa, a tensile strength of 837 MPa, an elongation of 45%, an average impact energy of 214 J at -196℃, and a thickness of 14.0 mm.

[0134] At room temperature, high manganese steel sheets are cold-stamped using a stamping press to obtain a bowl-shaped blank through a one-time stamping process.

[0135] Under the condition that the processing temperature is controlled at 200℃, the bowl-shaped blank is subjected to warm spinning to the finished diameter size to obtain a high manganese steel end cap.

[0136] The dimensions of the high-manganese steel head obtained in this comparative example meet the design requirements of the drawings, but visible micro-cracks appear on the surface of the vertical end, which does not meet the requirements.

[0137] Comparative Example 2:

[0138] The high-manganese steel sheet has a Mn content of 22.46%, a yield strength of 428 MPa, a tensile strength of 837 MPa, an elongation of 45%, an average impact energy of 214 J at -196℃, and a thickness of 14.0 mm.

[0139] At room temperature, high manganese steel sheets are cold-stamped using a stamping press to obtain a bowl-shaped blank through a one-time stamping process.

[0140] The bowl-shaped blank is heated to the finished diameter at a processing temperature controlled at 350℃ to obtain a high-manganese steel end cap.

[0141] The dimensions of the high-manganese steel head obtained in this comparative example meet the design requirements of the drawings, but visible micro-cracks appear on the surface, and there are open cracks in the end weld.

[0142] Figure 2 This paper shows a cross-sectional schematic diagram of the high-manganese steel head prepared according to Example 1 of this application. Figure 3 This shows a schematic diagram of the overall shape of the high-manganese steel head prepared in Embodiment 1 of this application. Combined with... Figure 2 , Figure 3 As can be seen from the above embodiments and comparative examples, the processing method for high-manganese steel heads provided in this application achieves uniform deformation of the high-manganese steel sheet during processing, and maintains a certain temperature for the bowl-shaped blank before and during the warm spinning process to avoid temperature drop, reduce the occurrence of head cracking, lower the scrap rate of the heads, improve economic efficiency, and reduce overall production costs. In addition, the high-manganese steel heads prepared by the processing method provided in this application have regular shapes and fully meet the dimensional requirements of the finished heads.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method of machining a high manganese steel head, characterized in that, The method includes: High manganese steel sheets are subjected to cold drum treatment to obtain a bowl-shaped blank, wherein the drum pressure of the cold drum treatment is 12MPa-20MPa and the duration is 4h-8h. The bowl-shaped blank is heated to obtain a preheated blank; The preheated blank is subjected to hot spinning treatment to obtain the high-manganese steel end cap. The high-manganese steel sheet is subjected to cold drum forming to obtain a bowl-shaped blank, comprising: The high-manganese steel sheet is subjected to a first cold drum treatment using a first die head; A second die is used to perform a second cold beating process on the high-manganese steel sheet that has undergone the first cold beating process, to obtain the bowl-shaped blank. The diameter of the first die is larger than the diameter of the second die. The bowl-shaped blank is heated to obtain a preheated blank, comprising: The bowl-shaped blank is fed into a heating furnace, and the furnace temperature is controlled within a first preset temperature range. The heating furnace is subjected to heat preservation treatment to obtain the preheated blank. The preheated blank is subjected to hot spinning treatment to obtain the high-manganese steel head, comprising: Under the condition that the processing temperature is controlled within the second preset temperature range, the preheated blank is subjected to hot spinning treatment to obtain the high manganese steel end cap. The high-manganese steel sheet contains weld seams. Before performing cold drum treatment on the high-manganese steel sheet, the method further includes: The high-manganese steel sheet is subjected to weld defect inspection, and high-manganese steel sheets with weld defects are determined to be unprocessable sheets. The weld defects include one or more of the following: weld porosity, weld voids, and weld bubbles. The method satisfies one or more of the following conditions: (1) The diameter of the first mold head is 1350mm-1450mm; (2) The diameter of the second die head is 1200mm-1300mm; (3) The duration of the first cold drum treatment is 2h-5h; (4) The duration of the second cold drumming process is 2-3 hours. The method satisfies one or more of the following conditions: (1) The first preset temperature range is 250℃-450℃; (2) The heat preservation treatment time is 12-15 minutes. The second preset temperature range is 250℃-400℃.

2. The method of machining a high manganese steel head according to claim 1, characterized in that, Before heat treatment of the bowl-shaped blank, the method further includes: Anti-slip blocks are welded to the bottom outer surface of the bowl-shaped blank; In the case where the high-manganese steel sheet contains at least one weld, a crack-preventing block is welded at the location of the weld in the end region of the bowl-shaped blank.

3. The processing method of the high manganese steel head according to claim 1, characterized in that, The high-manganese steel sheet meets one or more of the following conditions: (1) The Mn content of the high manganese steel sheet is 22%-26%; (2) The yield strength of the high manganese steel sheet is 400MPa-550MPa; (3) The tensile strength of the high manganese steel sheet is 800MPa-950MPa; (4) The elongation of the high-manganese steel sheet is 35%-65%; (5) The Charpy impact energy KV of the high manganese steel sheet at -196℃ is 60J-300J.

Images