Manufacturing method of roller for ultra-wide aluminum plate rolling mill

Abstract

The invention discloses a manufacturing method of a roller for an ultra-wide aluminum plate rolling mill, and belongs to the field of roller manufacturing. The roller comprises the following chemical components: 0.3%-1.0% of C, 5.0%-13.0% of Cr, 0.5%-2.0% of Mo, 0.05%-0.5% of V, less than or equal to 2% of W and less than or equal to 2% of Co; according to heat treatment of the roller, overall hardening and tempering are conducted firstly, and then high-temperature surface hardening is conducted on a roller body in a differential temperature furnace; the quenching temperature of hardening and tempering is Ac1 + 20-30 DEG C, the high-temperature surface quenching temperature is Ac3 + 50-60 DEG C, the temperature at the depth of a use layer is greater than or equal to Ac3 + 20 DEG C, the quenched roller surface is cooled to be below 80 DEG C during cooling, and the temperature return after water cooling is not higher than 300 DEG C. The method is suitable for production of the roller for the aluminum plate rolling mill with the length of the roller body exceeding 5000 mm, the mechanical performance of the roller neck can meet the use requirement, the hardness of the roller body is uniform, and the depth of a hardening layer, residual austenite, stress and the like can meet the designed service life.

Description

Technical Field

[0001] This invention belongs to the field of rolling mill manufacturing technology. In particular, it is a method for manufacturing rolling mill rolls for ultra-wide aluminum plates of 3300mm and above. Background Technology

[0002] The specifications of aluminum and steel sheets used in industry are becoming increasingly larger, with current requirements for ultra-wide aluminum sheets exceeding 3300mm in width. This necessitates increasingly larger rolling mills and rolls used in aluminum sheet production, with roll lengths reaching 5m, roll diameters between 800-1300mm, and total roll lengths between 6-12m. Achieving uniform strength and hardness in such massive rolls, free from localized soft spots or hardness deviations, presents significant challenges in the metallurgical, forging, and heat treatment processes.

[0003] In metallurgy, since large rolling mill rolls require separate ingot production, controlling the chemical composition and uniformity of the steel's microstructure during steelmaking is a fundamental process. Further refining and homogenizing the chemical composition and microstructure of the steel during the forging process is also crucial. However, due to the excessively large dimensions of the rolls, sufficient reinforcing alloys must be added to the steel to increase hardness. The size of the casting molds after smelting the ingots for large rolls is also limited. Furthermore, the cost and consumption of repeated forging during the subsequent forging process are too high. Therefore, controlling the quality of heat treatment is of paramount importance. How to heat treat ultra-large rolling mill rolls to meet product quality requirements is a significant challenge in this industry.

[0004] A rolling mill roll generally consists of the roll body, which is the working part, and the roll necks at both ends of the roll body. The roll necks are used to install, support, and drive the roll to rotate. Due to the inevitable compositional and microstructure segregation during the casting and forging processes of the rolling mill roll steel, this results in an excess of residual austenite and high local stress in the internal material of the roll after heat treatment. If these defects occur at the roll neck, they can cause deformation, cracks, or premature wear failure of the roll, thus affecting its use and safety.

[0005] In the final heat treatment process of quenching the rolls, due to their large size, insufficient heat penetration and inadequate internal cooling rate may occur during quenching. This can lead to insufficient hardened layer and excessive hardness drop from the surface to the core of the roll, resulting in severe performance degradation and a short service life. If soft spots or uneven hardness occur on the surface of the hardened layer during quenching, it will cause uneven wear of the roll during use, resulting in an uneven surface and uneven thickness of the rolled sheet, failing to meet product quality requirements. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a manufacturing method for rolls used in ultra-wide aluminum plate rolling mills. This method is a production method proposed in terms of metallurgy and heat treatment for rolls used in aluminum plate rolling mills with roll lengths exceeding 5000mm. After heat treatment, the mechanical properties of the roll neck can meet the usage requirements, and the hardness of the roll body, the depth of the hardened layer, the residual austenite, and the stress can all meet the design life.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for manufacturing rolls for ultra-wide aluminum plate rolling mills includes ingot smelting, roll blank forging, and roll heat treatment processes. During ingot smelting, the final chemical composition of the rolls is controlled to be 0.3%–1.0% C, 5.0%–13.0% Cr, 0.5%–2.0% Mo, 0.05%–0.5% V, ≤2% W, and ≤2% Co. The roll heat treatment process involves first performing overall quenching and tempering on the rough roll blank after rough machining, and then quenching the roll body at high temperature after forming the finished roll blank. The quenching and tempering process involves heating at Ac1+20–30℃ and holding for 2–4 hours, followed by oil cooling. The tempering and tempering process involves holding at 580–650℃ for 8–10 hours. The high-temperature surface hardening of the roll body is carried out by differential temperature heat treatment to locally heat the roll body. The heating temperature of the high-temperature surface hardening is Ac3+50~60℃, and the heating rate is controlled at more than 360℃ / h. After reaching the temperature, the austenitization time is controlled at 20~60min to ensure that the temperature at the working layer depth of the roll body is ≥Ac3+20℃. The cooling of the high-temperature surface hardening is carried out by water spray cooling and the quenched roll surface is kept below 80℃ for 30~60min. The tempering process after high-temperature surface hardening is 500~560℃ for 18~22 hours. Before the high-temperature surface hardening, the entire roll is preheated at 500~560℃ for 10~18h.

[0008] A further improvement of the technical solution of the present invention is that: the forging adopts a heavy pressure fast forging method, the forging heating temperature is 1210-1240℃, the single forging reduction rate is within 15-18%, the final forging temperature is higher than 850℃, and the overall forging ratio is greater than 5.0.

[0009] A further improvement of the technical solution of the present invention is that the heating and heat preservation of the high temperature surface quenching is carried out in a differential temperature furnace. The roll body is placed in the differential temperature furnace, while the roll neck is placed outside the differential temperature furnace. The heating burners in the differential temperature furnace are evenly arranged in 4 to 8 rows along the circumference of the roll body and 4 to 5 in the axial direction per meter. The roll should be rotated circumferentially in the differential temperature furnace.

[0010] A further improvement of the technical solution of the present invention is that when the roll is subjected to high-temperature surface quenching and heat preservation in the differential temperature furnace, the roll neck at the furnace mouth is insulated by wrapping it with ceramic fiber. At the same time, the part of the roll neck outside the furnace is not wrapped and the temperature of the roll neck outside the furnace is kept not higher than 560°C.

[0011] A further improvement of the technical solution of the present invention is that the rotational speed of the roll in the differential temperature furnace is 1 to 2 revolutions per minute.

[0012] A further improvement of the technical solution of the present invention is that: during the heating and heat preservation process of high temperature surface quenching, the depth of the roll body reaching a temperature of Ac3 or above should meet the requirements of the roll service layer depth but be ≤20% of the roll body radius.

[0013] A further improvement of the technical solution of the present invention is that: in the process of water spraying cooling during high-temperature surface quenching, the water spray nozzles are evenly distributed in 4 to 6 rows along the circumference of the roll body with an axial spacing of 100 to 150 mm, and the roll is kept rotating at 4 to 8 revolutions per minute, and the water spray volume is controlled at 30 to 50 L / min per square meter of roll surface.

[0014] A further improvement of the technical solution of the present invention is that: during water spray cooling, the amount of water sprayed in the area of ​​0 to 200 mm from the edge of the surface of the quenched roller body is reduced by 15% to 20% every 10 minutes.

[0015] A further improvement of the technical solution of the present invention is that: during the water spray cooling process, a baffle plate is set at the connection between the roller neck and the roller body to prevent the cooling water from impacting the roller neck; after the water spray cooling is completed, air cooling or blowing cooling is used to allow the roller surface to slowly return to 200-300°C but no longer continue to rise.

[0016] A further improvement of the technical solution of the present invention is that the tempering after the high-temperature surface quenching needs to be carried out twice. During the first tempering loading, the temperature of the rolls and the tempering furnace are both in the range of 200-300℃.

[0017] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows: By employing the chemical composition of the roll steel specified in this invention and combining various heat treatment measures, when producing rolls for rolling mills used to roll aluminum plates and other non-ferrous metal plates with a width of 3300mm and above, the roll neck and core are both in a quenched and tempered state. The microstructure of the roll neck and core is carbide + tempered sorbite, with a hardness of 35-50HS, meeting the usage requirements throughout the roll's entire life cycle and preventing problems or accidents such as deformation or breakage. The roll body's service layer is in a quenched and tempered state, with a microstructure of carbide + tempered martensite, a hardness of 65-80HS, uniformity ≤3HS, and a hardened layer depth ≥45mm. It maintains good wear resistance and uniform wear throughout its entire life cycle, meeting the requirements for hot rolling of ultra-wide aluminum plates and other non-ferrous metals. The final residual austenite content in the hardened layer of the roll body treated by the method of this invention is <2%, and the roll surface stress is -400 to -50MPa, meeting the safety requirements throughout the entire life cycle. Detailed Implementation

[0018] This invention discloses a method for manufacturing rolls for ultra-wide aluminum plate rolling mills, applicable to rolls made of high-speed steel with a roll body length exceeding 3300 mm. The roll body length of such rolls is generally 3300–5000 mm, the roll body diameter is generally 800–1300 mm, and the total roll length is 6000–12000 mm. The roll is entirely made of forged high-speed steel. The manufacturing process of such rolls generally involves steelmaking and casting into steel ingots, forging the steel ingots into roll blanks, then rough machining to form a rough roll blank, quenching and tempering the rough roll blank, followed by semi-finishing to form a finished roll blank, then final heat treatment (roll body surface quenching), and finally finishing to form the roll. The processes for controlling the chemical composition, microstructure, and mechanical properties of the roll in this invention include steel ingot smelting, roll blank forging, and roll heat treatment.

[0019] During the steel ingot smelting process, the final chemical composition of the rolls needs to be controlled to be 0.3%–1.0% C, 5.0%–13.0% Cr, 0.5%–2.0% Mo, 0.05%–0.5% V, ≤2% W, and ≤2% Co. The chemical composition of the steel used in this invention can be customized within the range of each chemical element according to the user's requirements for the mechanical properties of the rolls, so that each alloying element can exert a synergistic effect, optimize the distribution and morphology of carbides in the steel, and balance the hardness and toughness of the rolls; tungsten and cobalt can be selectively added according to the user's requirements for the red hardness of the rolls. The forging process involves forging the steel ingot that has been smelted and cast. The forging heating temperature is 1210-1240℃, and the holding time is more than 10 hours. A pressure rolling mill of 8000MN or above is used. The single forging reduction rate is within 15-18%. The core of the steel ingot is avoided by heavy pressure and fast forging. The final forging temperature should be higher than 850℃. The overall forging ratio should be greater than 5.0 to ensure that the steel ingot is forged through, break up large grains and columnar crystal structures, compact the internal porosity and gap defects of the steel ingot, and improve the mechanical properties of the rolls to form roll blanks that meet the requirements of roll diameter, total length and flaw detection quality.

[0020] The heat treatment process of this invention includes a quenching and tempering heat treatment process and a final heat treatment process. After rough machining of the roll blank, the roll blank undergoes quenching and tempering heat treatment. Before heat treatment, the temperatures of points Ac1 and Ac3 of the steel need to be measured, and then the heating and holding temperatures during quenching are determined based on the temperatures of points Ac1 and Ac3 of the steel in the furnace. The quenching and tempering heat treatment of this invention involves overall quenching and tempering of the roll blank. The quenching process during quenching and tempering is as follows: the blank is heated to a temperature range of 20-30°C above Ac1 (Ac1 + 20-30°C) and held at this temperature for 2-4 hours, followed by oil cooling. The oil cooling rate should ensure that the quenched steel has sufficient hardness and fine grains. The tempering process during quenching and tempering is held at 580-650°C for 8-10 hours. After this quenching and tempering heat treatment, fine grains should be formed in the service layer of the roll body, and most of the residual austenite and stress should be eliminated. The hardness of the roll neck should reach ≥HS35, and the impact energy should be ≥30J, forming stable comprehensive mechanical properties.

[0021] After tempering, the rough roll blank is machined to form the finish roll blank. The final heat treatment after the finish roll blank is then performed. This process mainly involves high-temperature quenching of the roll body to meet the requirements for hardness and uniformity, while simultaneously ensuring the strength of the roll neck and the entire roll. The high-temperature quenching of the roll body is achieved by heating the roll body surface using differential temperature heat treatment, a localized surface quenching process. The main equipment used for this localized high-temperature surface quenching is a differential temperature heat treatment furnace. Before heating in the differential temperature furnace, the entire roll can be preheated in another heat treatment furnace. Preheating involves placing the entire roll into the preheating furnace. The preheating temperature should be set between 500 and 560°C, not exceeding the tempering temperature of the tempering process, and the holding time should be set between 10 and 18 hours to ensure that the core of the entire roll reaches 500°C or higher. This ensures that the performance of the roll neck remains unchanged and provides conditions for the austenitization depth of the roll body's working layer during quenching and holding.

[0022] When performing high-temperature surface quenching in a differential temperature furnace, the heating rate should be at least 360℃ / h. After heating to the austenitizing temperature of Ac3+50~60℃, hold for 20~60min to ensure sufficient austenitizing time and depth of austenitization on the roll surface. The temperature at the required roll body service layer depth should be ≥Ac3+20℃. This ensures that the depth of the roll body reaching temperatures above Ac3 meets the roll service layer depth requirements, but the depth reaching temperatures above Ac3 should be ≤20% of the roll body radius. This satisfies the thickness and hardness requirements of the entire service layer of the heat-treated roll body. Furthermore, it ensures that refractory alloying elements (W, Mo, V, etc.) are fully dissolved in the austenite to improve the roll's red hardness and control overall stress.

[0023] When performing high-temperature surface quenching and heat preservation in a differential temperature furnace, the roll body is placed inside the furnace, while the roll neck is placed outside. The roll neck at the furnace opening must be insulated. Insulation can be achieved by wrapping ceramic fibers around the roll neck at the furnace opening, but the portion of the roll neck outside the furnace is not wrapped. This ensures that the roll neck outside the furnace can dissipate heat effectively during the surface quenching and heat preservation process, preventing its temperature from exceeding 560℃. This prevents the roll neck temperature from exceeding the tempering temperature, which would degrade its mechanical properties.

[0024] The heating burners in the differential temperature furnace are arranged in 4-8 rows evenly along the circumference of the roll body, and 4-5 burners evenly arranged per meter axially. Throughout the heating and heat preservation process, the roll should rotate circumferentially within the furnace. This invention uses rollers to support the roll neck and drive the entire roll to rotate, with the circumferential rotation speed controlled at 1-2 revolutions per minute. This ensures uniform heating and consistent temperature across all parts of the roll body.

[0025] High-temperature surface hardening is achieved through water spray cooling, ensuring the quenched roll surface is cooled to below 80°C and held for 30–60 minutes. This cooling time can be adjusted according to the required hardening depth. During water spray cooling, the roll is placed on a rotary cooling device, with the roll neck lifted to rotate the entire roll. Water is sprayed onto the roll body using nozzles arranged around the roll body. The nozzles in the rotary cooling device are evenly distributed in 4–6 rows along the circumference of the roll body, with an axial spacing of 100–150 mm. The roll rotation speed is maintained at 4–8 revolutions per minute, and the water spray rate is controlled at 30–50 L / min per square meter of roll surface to ensure sufficient hardenability. During water spray cooling, within a range of 0–200 mm from the edge of the quenched roll body surface, the water spray rate should be reduced by 15%–20% every 10 minutes to avoid stress concentration areas forming between the edge of the quenched area and the non-quenched area. Meanwhile, before water spray cooling, a baffle plate can be installed at the transition area between the roll neck and the roll body to prevent the cooling water from impacting the roll neck during the water spray cooling process and causing stress at the roll neck. After water spray cooling is completed, air cooling or blower cooling should be used to continue cooling the roll, depending on the situation, to ensure that the roll surface can slowly return to 200-300°C. However, once it returns to this temperature range, the temperature of the roll surface will no longer continue to rise; otherwise, the speed of blower cooling needs to be increased.

[0026] After cooling following high-temperature surface quenching, the entire roll undergoes low-temperature tempering. The tempering process after high-temperature surface quenching involves holding at 500–560℃ for 18–22 hours. This tempering process requires two passes. During the first tempering, the temperature of both the roll and the tempering furnace is within the range of 200–300℃. After the two tempering processes, most of the retained austenite from quenching is transformed into tempered martensite, and fine carbide particles precipitate, resulting in a secondary hardening effect, improved wear resistance, elimination of most retained austenite (final retained austenite content <2%), and complete elimination of quenching stress (final roll surface stress -400 to -50 MPa).

[0027] The method of this invention enables uniform control of the thickness and hardness of the hardened layer on the roll body and the mechanical properties of the roll neck. The final roll neck and core are in a quenched and tempered state, with a microstructure of tempered sorbite + carbides and a hardness of 35–50 HS; the roll body's service layer is in a quenched and tempered state, with a microstructure of tempered martensite + carbides, a service layer hardness of 65–80 HS, and a uniformity ≤3 HS.

[0028] The technical effects of the present invention will be further verified below with reference to the embodiments: Example 1: The roll in this embodiment has a roll body diameter of 1100mm and a length of 4000mm, a layer thickness requirement of 35mm, and a hardness requirement of 75-80HS within the layer thickness range.

[0029] In this embodiment, the steel composition is controlled within the following ranges: C: 0.7%–0.9%, Cr: 8.0%–8.5%, Mo: 1.2%–1.5%, V: 0.4%–0.5%, W: 0.4%–0.5%. After smelting into steel ingots, the expansion of the heated steel ingot samples is measured using a thermal expansion meter. The phase transformation point is calculated based on the expansion and the final microstructure. Testing shows that the Ac1 temperature of this steel ingot is 795℃ and the Ac3 temperature is 890℃. After forging the steel ingot into roll blanks, rough machining is performed to form the roll blanks. After tempering heat treatment, the rough blanks undergo semi-finishing to form the roll blanks. The roll blanks are then surface-quenched, and finally finished to form deliverable rolls.

[0030] In this embodiment, the austenitizing temperature during quenching and tempering is 825–835°C, the holding time is 2.5 h, followed by oil cooling, and then tempering at 630°C for 10 h. The hardness of the quenched and tempered roll body and roll neck is 42HS.

[0031] In the final heat treatment process, before high-temperature quenching and tempering of the roll body surface, the preheating temperature is 580℃, and the holding time is 14 hours. After preheating, the roll body is hoisted into a differential temperature furnace and heated to the austenitizing temperature of 940-950℃ at a rate of 480℃ / h, and held for 45 minutes. After austenitizing, the roll body surface is cooled by water spraying for 60 minutes, followed by air blowing and air cooling for 150 minutes. After the roll body temperature stabilizes at 280℃, it is placed in a tempering furnace for tempering at 560℃ for 20 hours. After cooling to room temperature after tempering, the hardness of the roll body is tested to be 80-82HS, and then the tempering process of holding at 560℃ for 20 hours is repeated.

[0032] The final product testing showed a roll body hardness of 77-79HS, with a hardness uniformity of 2HS; a roll neck hardness of 40HS; a 40mm hardened layer as determined by roll body cross-section testing; 0% retained austenite in the roll body; and a stress of -310MPa. Roll neck cross-section testing revealed a tensile strength of 900MPa and an impact energy of 32J. This product, after delivery to the user, was used for hot-rolled aluminum sheets and intended for normal use until its scrapping.

[0033] Example 2: The roll in this embodiment has a diameter of 950mm and a length of 3600mm, with a layer thickness of 25mm and a hardness requirement of 65-70HS. The steel composition is selected as follows: C: 0.4%-0.5%, Cr: 5.5%-6.0%, Mo: 0.6%-0.8%, V: 0.1%-0.15%, Co: 0.1%-0.2%. After smelting into steel ingots, the Ac1 temperature and Ac3 temperature of the material were measured to be 785℃ and 885℃, respectively. The tempering process in this embodiment is as follows: quenching temperature 815-825℃, holding for 2 hours, oil cooling, and tempering at 580℃ for 8 hours. After tempering, the hardness of the roll body and roll neck is measured to be 39HS.

[0034] Before surface quenching and tempering the roll body, the preheating temperature is 560℃, and the holding time is 12 hours. After preheating, the roll body is hoisted into a differential temperature furnace and heated to the austenitizing temperature of 935-945℃ at a rate of 480℃ / hour, and held for 35 minutes. After austenitizing, the roll body is cooled by water spray for 40 minutes, followed by air cooling and blowing for 120 minutes. Once the roll temperature stabilizes at 270℃, it is placed in a tempering furnace for tempering at 520℃ for 18 hours. After the first tempering and cooling to room temperature, the roll body hardness is measured to be 73-74 HS, and then the tempering process is repeated once more at 530℃ for 18 hours.

[0035] The final product's roll body hardness was 68-70HS, with a hardness uniformity of 2HS; the roll neck hardness was 38HS; a 30mm hardened layer was observed from a roll body cross-section; the roll body showed 0% residual austenite content and a stress of -170MPa; and the roll neck cross-section showed a tensile strength of 850MPa and an impact energy of 33J. After delivery to the user, the product was used for hot-rolled aluminum sheets and was intended for normal use until scrapping.

Claims

1. A method for manufacturing rolls for ultra-wide aluminum plate rolling mills, comprising ingot smelting, roll blank forging, and roll heat treatment processes, characterized in that: The final chemical composition of the rolls during the steel ingot smelting process is controlled to be 0.3%–1.0% C, 5.0%–13.0% Cr, 0.5%–2.0% Mo, 0.05%–0.5% V, ≤2% W, and ≤2% Co. The heat treatment process for the rolls involves first performing overall quenching and tempering on the rough roll blank after mechanical roughing, followed by high-temperature quenching of the roll body after the roll blank is formed. The quenching and tempering process involves heating at Ac1+20–30℃ and holding for 2–4 hours, followed by oil cooling. The tempering and tempering process involves holding at 580–650℃ for 8–10 hours. The high-temperature surface quenching of the roll body is achieved using differential temperature heat treatment. The roll body is locally heated using a specific method. The heating temperature for high-temperature surface quenching is Ac3+50~60℃, and the heating rate is controlled at 360℃ / h or higher. After reaching the desired temperature, the austenitization time is controlled at 20~60min to ensure that the temperature at the working layer depth of the roll body is ≥Ac3+20℃. The cooling of the high-temperature surface quenching is achieved by water spray cooling, and the quenched roll surface is kept below 80℃ for 30~60min. The tempering process after high-temperature surface quenching is to hold at 500~560℃ for 18~22 hours. Before high-temperature surface quenching, the entire roll is preheated at 500~560℃ for 10~18h.

2. The method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 1, characterized in that: The forging process adopts a heavy-pressure fast forging method, with a forging heating temperature of 1210-1240℃, a single forging reduction rate of 15-18%, a final forging temperature of over 850℃, and an overall forging ratio greater than 5.

0.

3. The method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 1, characterized in that: The heating and heat preservation for high-temperature surface quenching is carried out in a differential temperature furnace. The roll body is placed inside the differential temperature furnace, while the roll neck is placed outside the differential temperature furnace. The heating burners inside the differential temperature furnace are evenly arranged in 4 to 8 rows along the circumference of the roll body and 4 to 5 evenly arranged per meter along the axial direction. The roll should be rotated circumferentially inside the differential temperature furnace.

4. The method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 3, characterized in that: When the rolls are subjected to high-temperature surface quenching and heat preservation in a differential temperature furnace, the roll neck at the furnace opening should be insulated with ceramic fiber. At the same time, the part of the roll neck outside the furnace should not be wrapped and the temperature of the roll neck outside the furnace should be kept not higher than 560°C.

5. The method for manufacturing a roll for an ultra-wide aluminum plate rolling mill according to claim 3, characterized in that: The circumferential rotation speed of the rolls in the differential temperature furnace is 1 to 2 revolutions per minute.

6. A method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to any one of claims 1-5, characterized in that: During the heating and heat preservation process of high-temperature surface hardening, the depth of the roll body reaching a temperature above Ac3 should meet the requirements of the roll service layer depth but be ≤20% of the roll body radius.

7. The method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 1, characterized in that: In the high-temperature surface quenching water cooling process, the water spray nozzles are evenly distributed in 4 to 6 rows along the circumference of the roll body with an axial spacing of 100 to 150 mm, and the roll is kept rotating at 4 to 8 revolutions per minute. The water spray volume is controlled at 30 to 50 L / min per square meter of roll surface.

8. A method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 7, characterized in that: During water spray cooling, the amount of water sprayed in the area of ​​0-200mm from the edge of the quenched roller surface is reduced by 15%-20% every 10 minutes.

9. A method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to any one of claims 7 and 8, characterized in that: During the water spray cooling process, a baffle plate is installed at the connection between the roll neck and the roll body to prevent the cooling water from impacting the roll neck; after the water spray cooling is completed, air cooling or blowing cooling is used to allow the roll surface to slowly return to 200-300℃ but no longer continue to rise.

10. A method for manufacturing rolls for ultra-wide aluminum plate rolling mills according to claim 1, characterized in that: The tempering after high-temperature surface quenching needs to be carried out twice. During the first tempering, the temperature of the rolls and the tempering furnace is in the range of 200-300℃.