Battery roller blank and preparation method thereof
By adopting high-temperature vacuum treatment and upsetting and drawing forging methods during the forging of battery rolls, the problems of long production cycle, high cost and concave of finished rolls are solved, and a more efficient and economical manufacturing process is achieved. High-quality finished product.
Patent Information
- Application Number
- CN202411609010.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-02-18
AI Technical Summary
The production cycle of battery roll forging is long and the cost is high, and the roller neck end surface of the finished battery roll is prone to concave.
Heat the steel water in the refining furnace to 1630-1650℃, perform vacuum treatment and pour, and take the steel ingot forging twice, and finally carry out the finished product to draw the temperature and insulation time to control the heating temperature and insulation time to ensure sufficient forging of the blank. combine.
The manufacturing process of battery roll roll blanks is shortened, the production cycle and cost is reduced, the center is avoided from the end surface of the finished roll neck, and the yield and ingot utilization rate are improved.
Smart Images
Figure CN119464627A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of roller manufacturing, and in particular to a battery roller blank and a preparation method thereof. Background Art
[0002] The battery roller is an important part of the battery electrode roller press, mainly used to produce the positive and negative electrodes of lithium batteries. It is made of high-strength metal materials with high hardness and high precision. Due to the high quality requirements of battery rollers, they are traditionally produced by forging electroslag ingots. The electroslag ingots are made by remelting the electrode blank electroslag. The electroslag ingots used for forging are cold ingots. The cold electroslag ingots must be preheated and gas-cut to discard the riser end, and then heated in a high-temperature furnace for forging. The production cycle is long and the cost is high. In addition, the battery roller is prone to concave center on the roll neck end when the roller is drawn and cut into finished products. Summary of the invention
[0003] The problem solved by the present invention is how to solve the problems of long production cycle and high cost in forging production of battery rollers and easy concavity of the roller neck end surface of the finished battery roller.
[0004] In order to solve the above problems, the present invention provides a battery roller blank and a preparation method thereof.
[0005] In a first aspect, the present invention provides a method for preparing a battery roller blank, comprising the following steps:
[0006] S1: heating molten steel in a refining furnace to a temperature of 1630-1650°C, filling the refining furnace with argon gas for vacuum treatment to make the vacuum degree ≤ 2 Torr, pouring molten steel, and demolding to obtain a steel ingot;
[0007] S2: Take the steel ingot and place it in a heating furnace, perform two upsetting and drawing forgings to obtain a blank with an upsetting ratio of 1.5-2, the temperature in the heating furnace is controlled at 1230±10℃, and the upsetting holding time is more than 10 hours each time;
[0008] S3, take the blank and carry out the second drawing to produce the finished product, heat the temperature to 1180±10℃, and keep it warm for 9-11 hours, draw the blank and cut it into the battery roller blank.
[0009] Optionally, in S3, the obtained battery roller blank is a roller blank with a roller body diameter not exceeding 800 mm and two pieces connected by a jaw at the roller head, and also includes step S4: gas cutting the jaws to separate the material, producing two pieces from one ingot, and obtaining two battery roller blanks with a specification not exceeding Φ800 mm.
[0010] Optionally, in step S1, during the vacuum treatment in the refining furnace filled with argon, the argon flow rate is maintained at 150-400 Nl / min, so that the vacuum degree is ≤2 Torr, and maintained for more than 17 minutes, and then the argon flow rate is reduced to 8-150 Nl / min, and maintained for more than 3 minutes. The total vacuum time of argon filling in the refining furnace is ≤50 min.
[0011] Optionally, the pouring speed of the molten steel in step S1 is 1.5-2 T / min.
[0012] Optionally, the stretching method in step S2 is upper flat and lower V-anvil stretching.
[0013] Optionally, step S2 specifically includes: in the first firing, the steel ingot is placed in a heating furnace, the temperature in the heating furnace is controlled to be 1230±10°C, and the temperature is kept for more than 10 hours, the steel ingot is pressed by a 4500T press to obtain a Φ950mm jaw, a spherical upsetting cover plate and an upsetting drain plate are used to upset to a height H=1000mm and a diameter Φ1615mm, and an upper flat lower V anvil is stretched to a diameter of Φ1100mm and a length of L=2150mm;
[0014] In the second firing, the temperature in the heating furnace is controlled at 1230±10℃ and kept warm for more than 10 hours. A spherical upsetting cover plate and an upsetting leak plate are used to upset to a height of H=1300mm and a diameter of Φ1615mm. The upper flat and lower V-anvil are stretched to a diameter of Φ1100mm and a length of L=2150mm to obtain a blank with an upsetting ratio of 1.5-2.
[0015] Optionally, in step S3, the blank is stretched to a diameter of Φ850 mm and a length of L=3510 mm using an upper flat and lower V-shaped anvil.
[0016] Optionally, step S3 further includes the step of performing post-forging heat treatment on the battery roller blank, wherein the post-forging heat treatment adopts 940-960°C normalizing, 810-830°C spheroidizing annealing and 710-730°C hydrogen expansion annealing.
[0017] Optionally, the steel ingot in step S1 is transferred to a heating furnace within 30 minutes after demoulding.
[0018] In a second aspect, the present invention provides a battery roller blank, which is made using the method for preparing a battery roller blank as described in any one of the above items.
[0019] The battery roller blank and the preparation method thereof of the present invention have the following beneficial effects: a steel ingot is prepared by pouring molten steel heated to a temperature of 1630-1650°C, and the steel ingot is directly placed in a heating furnace for forging without preheating, which greatly shortens the manufacturing process of the battery roller blank and reduces the production cycle and cost; the steel ingot is compacted by two upsetting and two drawing steps to ensure the compaction effect of the blank and avoid the concave center of the roll neck end face of the finished product; the furnace temperature of the two upsetting and drawing steps is controlled at 1230±10°C, and increasing the heating temperature is conducive to the mutual diffusion of atoms on the defect wall, making the defects in the blank easier to weld; the furnace temperature of the finished product drawing step is controlled at 1180±10°C, and the finished product is kept warm for 9-11 hours at the same time, and the keeping time is controlled to reduce the growth of the grains of the blank, effectively forging the cast defects in the core of the cast steel ingot, ensuring that the battery roller blank can meet the requirements of flaw detection and acceptance, improving the yield rate, and then improving the utilization rate of the steel ingot, and effectively reducing the manufacturing cost of the roller blank. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 This is a flow chart of a method for preparing a battery roller blank of this embodiment;
[0021] Figure 2 This is a schematic diagram of the structure of the blank of Example 1;
[0022] Figure 3 This is a schematic diagram of the structure of the blank of Example 2;
[0023] In the figure: 1. nozzle end; 2. roller head; 3. roller neck; 4. roller body; 5. jaws. DETAILED DESCRIPTION
[0024] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be interpreted as being limited to the embodiments described herein. On the contrary, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.
[0025] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the art to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific implementation methods and are not intended to limit this application;
[0026] The term "including" and its variations used in this article are open inclusions, that is, "including but not limited to"; the term "based on" is "based at least in part on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments"; the term "optionally" means "optional embodiments". The relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first" and "second" mentioned in the present invention are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, the meaning of "multiple" is two or more.
[0027] In view of the problems existing in the above-mentioned related technologies, this embodiment provides a battery roller blank and a preparation method thereof.
[0028] A method for preparing a battery roller blank provided in an embodiment of the present invention comprises the following steps:
[0029] S1: heating molten steel in a refining furnace to a temperature of 1630-1650°C, filling the refining furnace with argon gas for vacuum treatment to make the vacuum degree ≤ 2 Torr, pouring molten steel, and demolding to obtain a steel ingot;
[0030] S2: Take the steel ingot and place it in a heating furnace, perform two upsetting and drawing forgings to obtain a blank with an upsetting ratio of 1.5-2, the temperature in the heating furnace is controlled at 1230±10℃, and the upsetting holding time is more than 10 hours each time;
[0031] S3. Take the blank and draw it out for the second time, heat it to 1180±10℃, and keep it warm for 9-11 hours, draw the blank and cut it into the blank to obtain the battery roller blank.
[0032] In this embodiment, the steel ingot is prepared by pouring molten steel heated to a temperature of 1630-1650°C. The steel ingot does not need to be preheated and is directly placed in a heating furnace for forging, which greatly shortens the manufacturing process of the battery roller blank and reduces the production cycle and cost. The two-upsetting and two-drawing method is used for compaction to ensure the compaction effect of the blank and avoid the formation of a concave center at the end face of the roller neck of the finished product, i.e., the roller head. The furnace temperature of the two upsetting and drawing processes is controlled at 1230±10°C. Increasing the heating temperature is conducive to the mutual diffusion of atoms on the defect wall, making the defects in the blank easier to weld. The furnace temperature of the finished product drawing process is controlled at 1180±10°C, and the finished product is kept warm for 9-11 hours. The holding time is controlled to reduce the growth of the billet grains, effectively forge the cast defects in the core of the cast steel ingot, ensure that the battery roller blank can meet the requirements of flaw detection and acceptance, improve the yield rate, and then improve the utilization rate of the steel ingot, effectively reducing the manufacturing cost of the roller blank.
[0033] Specifically, the minimum holding time for the finished product is calculated by accumulating 50 minutes of holding time for every 100 mm of the billet diameter, and the maximum holding time is controlled according to the minimum holding time + 3 hours. Controlling the holding time can reduce the growth of the billet grains.
[0034] Specifically, the steel ingot obtained in step S1 needs to be completely cleaned of residual steel and slag on the inner surface, and the pits that affect demolding must also be polished to a smooth transition before it can be transferred to the heating furnace for forging.
[0035] Specifically, for rollers with a roller body diameter not exceeding 800 mm, a two-piece forging method is adopted, and for rollers with a roller body diameter exceeding 800 mm, a one-piece forging method is adopted, so as to avoid a concave center on the end face of the roller head of the finished product.
[0036] Optionally, in S3, the obtained battery roller blank is a roller blank with a roller body diameter not exceeding 800 mm and two pieces connected by jaws at the roller head, and also includes step S4: gas cutting jaws to separate the material, producing two pieces from one ingot, and obtaining two battery roller blanks with a specification not exceeding a diameter of Φ800 mm.
[0037] In this optional embodiment, a battery roller with a diameter of Φ800mm or less is produced in two pieces from one ingot, and the ingot is small (i.e., 15T-20T cast ingot). A jaw is provided at the roller head, and the roller neck and roller head are forged to the finished product size in the middle of the billet and then the material is divided at the jaw by gas cutting.
[0038] Specifically, if one ingot is used to forge one piece, the ingot mold needs to be raised. For example, one ingot forging two pieces is 19T / 2, one ingot forging one piece requires 10T / 1, and two pieces require 20T, which is an extra ton of material. If two products are produced at the same time, two ingots can be produced compared to one ingot for one piece, which reduces the number of forging fires; at the same time, the advantages of the relatively small ingot mold and convenient operation are taken advantage of, and the small press 4500T press is fully utilized to reduce production costs. If one ingot produces three or more pieces, the ingot mold is larger, and a large press 6000T press is required for production, which has high production costs.
[0039] Specifically, the blank with jaws only needs to lengthen the blanking length of the roll neck and the roll head at the other end of the blank, namely the nozzle end, by 50 mm to 100 mm, which can solve the problem of the concave center of the blanking at the roll head.
[0040] Optionally, in step S1, during the vacuum treatment in the refining furnace filled with argon, the argon flow rate is maintained at 150-400 Nl / min, so that the vacuum degree is ≤2 Torr, and maintained for more than 17 minutes, and then the argon flow rate is reduced to 8-150 Nl / min, and maintained for more than 3 minutes. The total vacuum time of argon filling in the refining furnace is ≤50 min.
[0041] In this optional embodiment, the timing starts after the vacuum degree is ≤2 Torr. The argon flow rate is relatively large from 0 to 17 minutes, and the argon flow rate is controlled at 150-400 Nl / min, so that the molten steel and the refining slag are fully mixed, which can effectively remove the gas and inclusions in the molten steel; the argon flow rate decreases from 17 to 20 minutes, and the argon flow rate is controlled at 80-150 Nl / min, in order to separate the molten steel and the refining slag. In the 20 minutes when the vacuum treatment starts, the vacuum degree is getting better and better. Excluding the 20 minutes when the vacuum degree is ≤2 Torr, there are 30 minutes left for the vacuum time. This 30 minutes includes the preliminary preparation process such as the refining bag entering the vacuum position and the vacuum pump starting to work, and the vacuum degree gradually decreasing. If the time is too long, it means that the preliminary preparation work is insufficient or other reasons such as vacuum equipment failure cause time delays, which will have a bad impact on product quality. Therefore, the total vacuum time of argon filling in the refining furnace is controlled to be ≤50 minutes.
[0042] Specifically, after vacuum treatment in the refining furnace, the gas is required to have [H]≤1.2ppm, [O]≤25ppm, and [N]≤70ppm.
[0043] Optionally, the pouring speed of the molten steel in step S1 is 1.5-2 T / min.
[0044] In this optional embodiment, the pouring time must be tight, argon protection must be used during pouring, and the pouring speed must be strictly controlled when pouring molten steel to ensure that the molten steel rises steadily in the mold, so that the surface quality of the ingot is good, which is conducive to the floating and discharge of gas and inclusions in the steel.
[0045] Optionally, the stretching method in step S2 is upper flat and lower V-anvil stretching.
[0046] In this optional embodiment, the upper flat and lower V-anvil pulling method increases the shear deformation of the blank compared to the upper and lower flat anvil pulling method, so that the internal defects of the blank are sheared and dispersed, which is beneficial to disperse the large defects in the blank into small dispersed defects that meet the requirements of flaw detection, thereby improving the flaw detection pass rate.
[0047] Optionally, step S2 specifically includes: in the first firing, the steel ingot is placed in a heating furnace, the temperature in the heating furnace is controlled to be 1230±10°C, and the temperature is kept for more than 10 hours, the steel ingot is pressed by a 4500T press to obtain a jaw with a diameter of Φ950mm, a spherical upsetting cover plate and an upsetting leak plate are used to upset to a height of H=1000mm and a diameter of Φ1615mm, and an upper flat lower V anvil is stretched to a diameter of Φ1100mm and a length of L=2150mm;
[0048] In the second firing, the temperature in the heating furnace is controlled at 1230±10℃ and kept warm for more than 10 hours. A spherical upsetting cover plate and an upsetting leak plate are used to upset to a height of H=1300mm and a diameter of Φ1615mm. The upper flat and lower V-anvil are stretched to a diameter of Φ1100mm and a length of L=2150mm to obtain a blank with an upsetting ratio of 1.5-2.
[0049] In this optional embodiment, two upsetting and two drawing methods are used for compaction to ensure the compaction effect of the blank and avoid the concave center of the roll neck end face of the finished product; the furnace temperature of the two upsetting and drawing is controlled at 1230±10℃ and kept warm for more than 10 hours. Increasing the heating temperature is conducive to the mutual diffusion of atoms on the defect wall, making the defects in the blank easier to weld, effectively forging the cast defects in the core of the cast steel ingot, ensuring that the battery roll blank can meet the requirements of flaw detection and acceptance, improving the yield rate, and then improving the utilization rate of steel ingots, effectively reducing the manufacturing cost of the roll blank. The 4500T press has a Φ950mm jaw, and the gas cutting jaw can be used for material separation, in preparation for obtaining two battery roll blanks with a specification not exceeding Φ800mm. At the same time, the advantages of relatively small ingots and convenient operation are taken advantage of to make full use of the small press 4500T press production to reduce production costs.
[0050] Specifically, "Φ" refers to the diameter size, for example, Φ950mm jaws means that the diameter at the jaws is 950mm, "H" refers to the height of the roller body of the billet, and "L" refers to the length of the billet. The billet is lengthened to Φ1100mm~L=2150mm by the upper flat and lower V-anvil, which means that the roller body diameter of the billet is 1100mm and the total length is 2150mm.
[0051] Specifically, the upper flat lower V anvil is a 400 upper flat lower V anvil. The upsetting leak plate is a Φ1000 upsetting leak plate, wherein the 400 upper flat lower V anvil refers to an upper flat lower V anvil with an anvil width of 400mm, and the Φ1000 upsetting leak plate refers to an upsetting leak plate with an inner hole of 1000mm.
[0052] Optionally, in step S3, the blank is stretched to a diameter of Φ850 mm and a length of L=3510 mm using an upper flat and lower V-shaped anvil.
[0053] In this optional embodiment, the finished product is drawn by upper flat and lower V-anvil drawing, which increases the shear deformation of the blank compared to upper and lower flat anvil drawing, so that the internal defects of the blank are sheared and dispersed, which is beneficial to disperse the large defects in the blank into small dispersed defects that meet the requirements of flaw detection, thereby improving the flaw detection pass rate.
[0054] Specifically, during the process of drawing and forging the finished product, it is necessary to avoid multiple forgings with a small reduction at the same position to avoid cracks in the blank.
[0055] Optionally, step S3 further includes the step of performing post-forging heat treatment on the battery roller blank, wherein the post-forging heat treatment adopts 940-960°C normalizing, 810-830°C spheroidizing annealing and 710-730°C hydrogen expansion annealing.
[0056] In this optional embodiment, post-forging heat treatment can eliminate the stress formed during the forging process and uniform the structure, while preventing the formation of white spots, refining the grains, adjusting the structure, and improving the performance of the product.
[0057] Optionally, the steel ingot in step S1 is transferred to a heating furnace within 30 minutes after demoulding.
[0058] In this optional embodiment, the steel ingot entering the heating furnace is ensured to be clean.
[0059] Specifically, before the steel ingot enters the heating furnace, the bottom of the ingot at the water inlet end is cut off to remove the bottom part of the ingot with poor quality due to the sinking of impurities.
[0060] Specifically, before a new ingot mold or an ingot mold that has not been used for more than 20 days is used again, the ingot mold should be baked. The main purpose of baking the ingot mold is to preheat it to improve baking efficiency and product quality while reducing production costs. The ingot mold needs to be preheated before use, usually to 80-120℃, which can ensure that the mold can better transfer heat when in use, improve baking efficiency and product quality.
[0061] A battery roller blank provided in an embodiment of the present invention is made by using the preparation method of a battery roller blank as described in any one of the above items.
[0062] The present invention is further described below in conjunction with specific embodiments.
[0063] Example 1
[0064] 20T casting ingot, one ingot produces two pieces, the preparation process of 9Cr3Mo battery roll blank is as follows:
[0065] 1. Preparation of cast steel ingots.
[0066] (1) Electric furnace smelting: Use recycled scrap steel + steel chips + light steel in an electric furnace to smelt molten steel whose chemical composition meets the composition requirements.
[0067] (2) Refining furnace smelting: refining molten steel in a ladle refining furnace.
[0068] (3) Vacuum treatment of refining furnace: Before vacuum treatment, the temperature of molten steel should be 1640℃, the vacuum degree should be ≤2 Torr and the holding time should be 20min. The argon flow rate should be maintained at 300Nl / min from 0 to 17min to reach the required vacuum degree. The argon flow rate should be reduced to 100Nl / min from 17 to 20min, and the total vacuum time should be 50min. The gas requirements are [H]≤1.2ppm, [O]≤25ppm, and [N]≤70ppm. After vacuum treatment, power should not be supplied, and steel can be tapped when the temperature reaches the tapping temperature.
[0069] (4) Pouring: Use pouring and argon to replace the air in each middle pouring pipe and mold before pouring the atmospheric ingot. The time from the refining furnace to the pouring must be tight. During pouring, argon protection is used, and the pouring speed is strictly controlled to 1.8T / min to ensure that the molten steel rises steadily in the mold.
[0070] (5) Demolding of steel ingot.
[0071] 2. Roller forging.
[0072] (1) Receive the hot steel ingot, cut off the bottom of the hot steel ingot at the water inlet end, and place it in the heating furnace.
[0073] (2) First fire: heating to 1230℃, keeping temperature for 10 hours. The steel ingot is pressed by 4500T press to obtain Φ950 jaw 5, and two roll blanks are pressed out, which are separated and connected by jaw 5 in the middle. The spherical upsetting cover plate and Φ1000mm upsetting drain plate are upset to H=1000mm~Φ1615mm, and the 400 upper flat lower V anvil is drawn to Φ1100mm~L=2150mm.
[0074] (3) Second fire: heat to 1230℃ and keep warm for 10 hours. Use spherical upsetting cover plate and Φ1000 upsetting drain plate to upset to H=1300mm~Φ1615mm, and 400 upper flat lower V anvil to lengthen to Φ1100mm~L=2150mm to obtain blank. Figure 2 .
[0075] (4) Finished product fire: Heat to 1180℃ and keep warm for 10 hours. Use 400 upper flat lower V anvil to pull to Φ850mm~L=3510mm, and pull out two finished products. Among them, the blank is at the nozzle end 1 (see Figure 2 The blanking length of the roll neck 3 and the roll head 2 at the left end of the roll body is appropriately lengthened by 50mm, which can further improve the problem of the concave center of the roll head 2. The jaws 5 in the middle of the two connected blanks are gas cut to obtain two battery roll blanks with a specification of Φ800mm (i.e., the diameter of the roll body 4 is 800mm).
[0076] 3. Heat treatment after forging: The heat treatment after forging adopts 940-960℃ normalizing, 810-830℃ spheroidizing annealing and 710-730℃ hydrogen expansion annealing.
[0077] Example 2
[0078] 16T ingot casting, one piece per ingot, the preparation process of 9Cr3Mo battery roll blank is as follows:
[0079] 1. Preparation of cast steel ingots.
[0080] (1) Electric furnace smelting: Use recycled scrap steel + steel chips + light steel in an electric furnace to smelt molten steel whose chemical composition meets the composition requirements.
[0081] (2) Refining furnace smelting: refining molten steel in a ladle refining furnace.
[0082] (3) Vacuum treatment of refining furnace: Before vacuum treatment, the temperature of molten steel should be 1640℃, the vacuum degree should be ≤2 Torr and the holding time should be 20min. The argon flow rate should be maintained at 300Nl / min from 0 to 17min to reach the required vacuum degree. The argon flow rate should be reduced to 100Nl / min from 17 to 20min, and the total vacuum time should be 50min. The gas requirements are [H]≤1.2ppm, [O]≤25ppm, and [N]≤70ppm. After vacuum treatment, power should not be supplied, and steel can be tapped when the temperature reaches the tapping temperature.
[0083] (4) Pouring: Use pouring and argon to replace the air in each middle pouring pipe and mold before pouring the atmospheric ingot. The time from the refining furnace to the pouring must be tight. During pouring, argon protection is used, and the pouring speed is strictly controlled to 1.8T / min to ensure that the molten steel rises steadily in the mold.
[0084] (5) Demolding of steel ingot.
[0085] 2. Roller forging.
[0086] (1) Receive the hot steel ingot, cut off the bottom of the hot steel ingot, and place it in the heating furnace.
[0087] (2) First fire: heat to 1230℃ and keep warm for 10 hours. Use 4500T press to press Φ950 jaws, spherical upsetting cover plate and Φ1000 upsetting drain plate to upset to H=1000mm~Φ1460mm, and 400 upper flat lower V anvil to lengthen to Φ1050mm~L=1920mm.
[0088] (3) Second fire: heat to 1230℃ and keep warm for 10 hours. Use spherical upsetting cover plate and Φ1000 upsetting drain plate to upset to H=1000mm~Φ1445mm, and 400 upper flat lower V anvil to lengthen to Φ1000mm~L=2090mm to obtain blank. Figure 3 .
[0089] (4) Finished product fire: Heat to 1180℃ and keep warm for 10 hours. Use 400 upper flat lower V anvil to pull to Φ950mm~L=2310mm, and pull out the finished product. Figure 3 The blanking length of the roller neck 3 and the roller head 2 at the left end is appropriately lengthened by 100 mm, which can further improve the problem of the concave center of the blanking at the roller head 2.
[0090] 3. Heat treatment after forging: The heat treatment after forging adopts 940-960℃ normalizing, 810-830℃ spheroidizing annealing and 710-730℃ hydrogen expansion annealing.
[0091] Effect Example
[0092] The ultrasonic flaw detection of the 9Cr3Mo battery roller blanks prepared in Example 1 and Example 2 was carried out in accordance with the provisions of GB / T13314-2008, wherein the roller body diameter <800mm (finished product size) was carried out in accordance with the prescribed Class A; the roller body diameter ≥800mm (finished product size) was carried out in accordance with the prescribed Class B. After ultrasonic flaw detection of the 9Cr3Mo battery roller blanks prepared in Example 1 and Example 2, no recorded defects were found. The 9Cr3Mo battery roller blanks prepared in Example 1 were subjected to a microstructure and performance test, and the test results are shown in Table 1, which shows that the test results meet the technical requirements; the 9Cr3Mo battery roller blanks prepared in Example 2 were subjected to a microstructure and performance test, and the test results are shown in Table 2, which shows that the test results meet the technical requirements.
[0093] Table 1, the results of the microstructure and performance test of the product 9Cr3Mo battery roll blank prepared in Example 1
[0094]
[0095]
[0096] Table 1, the results of the microstructure and performance test of the product 9Cr3Mo battery roll blank prepared in Example 1
[0097]
[0098] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.
Claims
1. A method for preparing a battery roller blank, characterized in that: The following steps are involved: S1: heating molten steel in a refining furnace to a temperature of 1630-1650° C., filling the refining furnace with argon gas for vacuum treatment to make the vacuum degree ≤ 2 Torr, pouring the molten steel, and demolding to obtain a steel ingot; S2: taking the steel ingot and placing it in a heating furnace, performing two upsetting and drawing forging operations to obtain a billet with an upsetting ratio of 1.5-2, wherein the temperature in the heating furnace is controlled at 1230±10° C., and the holding time for each upsetting operation is more than 10 hours; S3, taking the blank material for the finished product drawing, heating the temperature to 1180±10°C, and keeping the temperature for 9-11 hours, drawing and cutting the blank material to obtain a battery roller blank.
2. The method for preparing a battery roller blank according to claim 1, characterized in that: In the S3, the obtained battery roller blank is a roller blank with a roller body diameter not exceeding 800 mm and two pieces connected by a jaw at the roller head, and also includes step S4: gas cutting the jaws to separate the material, producing two pieces from one ingot, and obtaining two battery roller blanks with a specification not exceeding Φ800 mm.
3. The method for preparing a battery roller blank according to claim 1, characterized in that: In step S1, the argon flow rate is maintained at 150-400 Nl / min during the vacuum treatment of the refining furnace with argon gas, so that the vacuum degree is ≤2 Torr, and it is maintained for more than 17 minutes, and then the argon flow rate is reduced to 8-150 Nl / min and maintained for more than 3 minutes. The total vacuum time of argon filling in the refining furnace is ≤50min.
4. The method for preparing a battery roller blank according to claim 1, characterized in that: The pouring speed of pouring the molten steel in step S1 is 1.5-2 T / min.
5. The method for preparing a battery roller blank according to claim 2, characterized in that: The stretching method in step S2 is upper flat and lower V-anvil stretching.
6. The method for preparing a battery roller blank according to claim 5, characterized in that: Step S2 specifically includes: first firing, taking the steel ingot and placing it in a heating furnace, wherein the temperature in the heating furnace is controlled to be 1230±10°C, and the temperature is kept for more than 10 hours, pressing the steel ingot with a 4500T press to obtain a jaw with a diameter of Φ950mm, using a spherical upsetting cover plate and an upsetting drain plate to upset to a height of H=1000mm and a diameter of Φ1615mm, and stretching the steel ingot with an upper flat and lower V-shaped anvil to a diameter of Φ1100mm and a length of L=2150mm; In the second firing, the temperature in the heating furnace is controlled at 1230±10°C and kept warm for more than 10 hours. A spherical upsetting cover plate and an upsetting leak plate are used to upset to a height of H=1300mm and a diameter of Φ1615mm. The upper flat lower V-anvil is stretched to a diameter of Φ1100mm and a length of L=2150mm to obtain a blank with an upsetting ratio of 1.5-2.
7. The method for preparing a battery roller blank according to claim 6, characterized in that: In step S3, the blank is stretched to a diameter of Φ850 mm and a length of L=3510 mm using an upper flat and lower V-shaped anvil.
8. The method for preparing a battery roller blank according to claim 1, characterized in that: The step S3 also includes the following steps: performing post-forging heat treatment on the battery roller blank, wherein the post-forging heat treatment adopts 940-960°C normalizing, 810-830°C spheroidizing annealing and 710-730°C hydrogen expansion annealing.
9. The method for preparing a battery roller blank according to claim 1, characterized in that: The steel ingot in step S1 is transferred to the heating furnace within 30 minutes after demoulding.
10. A battery roller blank, characterized in that: The battery roller blank is manufactured by the method for preparing the battery roller blank as described in any one of claims 1 to 9.