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CN-121551384-B - Rolling method of large-specification TA15 titanium alloy super-thick plate

CN121551384BCN 121551384 BCN121551384 BCN 121551384BCN-121551384-B

Abstract

The invention discloses a rolling method of a large-size TA15 titanium alloy super-thick plate, which comprises the steps of firstly, forging a TA15 titanium alloy cast ingot in a beta single-phase region twice, forging an alpha+beta two-phase region twice and forging in a forming mode to obtain a TA15 titanium alloy plate blank, secondly, heating the TA15 titanium alloy plate blank in a stepped mode, thirdly, rolling the TA15 titanium alloy plate blank through one fire to obtain a TA15 titanium alloy rolled blank, fourthly, performing finished product heat treatment after turning over, performing reciprocating straightening and air cooling, and fifthly, performing shape correction treatment to obtain the finished product TA15 titanium alloy super-thick plate. The invention fully breaks the original beta grains through five-fire forging, stepped heating and one-fire rolling in sequence to obtain rolled billets with consistent structure and performance, and combines rapid water cooling treatment, heat treatment and shape correction treatment to inhibit grain growth and promote precipitation of strengthening phases to obtain the TA15 titanium alloy super-thick plate with fine grain size, small anisotropism and excellent performance, which is suitable for large-scale structural parts in the aviation and aerospace fields.

Inventors

  • ZHANG YIHENG
  • FU WENJIE
  • XIE YINGJIE
  • ZHAO ZHIWEI
  • LI PENG
  • LI WEI
  • HOU ZHIMIN

Assignees

  • 西部钛业有限责任公司

Dates

Publication Date
20260508
Application Date
20260126

Claims (6)

  1. 1. The rolling method of the large-specification TA15 titanium alloy super-thick plate is characterized by comprising the following steps of: Sequentially carrying out twice beta single-phase zone forging, twice alpha+beta two-phase zone forging and forming forging on a TA15 titanium alloy cast ingot to obtain a TA15 titanium alloy slab with the thickness of 300-360 mm, the width of 900-1250 mm and the length of 1500-2200 mm, wherein the TA15 titanium alloy slab meets the A1 technical requirement in GB/T5193-2020 ultrasonic inspection method of titanium and titanium alloy processed products, and the original beta grains of slab structure are fully crushed and have uniform structure; Coating the upper surface, the lower surface and the side surface of the TA15 titanium alloy plate blank obtained in the first step with an anti-oxidation coating, and then heating in a step heating mode, wherein the first step is subjected to heat preservation at 600 ℃, the temperature is raised to 800 ℃ along with a furnace after the heat preservation is finished, the temperature is raised to 920-940 ℃ along with the furnace after the heat preservation is finished; thirdly, performing primary fire rolling on the TA15 titanium alloy slab heated in the second step to obtain a TA15 titanium alloy rolled blank; the first-pass rolling is divided into three rolling passes, namely, the first rolling pass is carried out on a TA15 titanium alloy plate blank after heating, namely, the rolling pass deformation rate of one rolling pass is 5% -10%, the number of rolling passes is 2-3, the rolling speed is 3-4 m/s, the first rolling Cheng Gapi with the thickness of 250-304 mm and the width of 1500-290 mm and the length of 630-480 mm is obtained, then the first rolling Cheng Gapi is subjected to intermediate on-line furnace temperature compensation under the condition of 920-940 ℃, the reversing rolling of two rolling passes is carried out, the second rolling pass is carried out, namely, the rolling pass deformation rate of the reversing rolling first rolling pass is 8% -15%, the rolling pass number is 3-4, the rolling speed is 2-3 m/s, the second rolling Cheng Gapi with the thickness of 630-48 mm and the length of 1500mm is obtained, the second rolling process with the length of 1500-1500 mm is carried out, the second rolling process is carried out on the titanium alloy plate blank with the condition of the second rolling process at the temperature of 920-940 ℃ and the temperature compensation of 100-360 ℃ and the rolling speed of the third rolling process is carried out, namely, the reversing rolling process is carried out on the titanium alloy plate blank with the condition of the second rolling process is carried out under the condition of 100-360 ℃ and the temperature compensation of 2-360 ℃ and the rolling process is carried out, and the rolling process is carried out on the titanium alloy plate blank with the titanium plate blank with the speed is subjected to the rolling process to the speed of 360-up to rolling process; Turning the TA15 titanium alloy rolled blank obtained in the step three by using a plate turning machine, performing heat treatment on a finished product, rapidly performing 2-4 times of reciprocating straightening by using a straightener, and then performing air cooling to room temperature to obtain the heat-treated TA15 titanium alloy rolled blank; And fifthly, performing shape correction treatment on the TA15 titanium alloy rolled blank obtained in the fourth step to obtain a finished TA15 titanium alloy super-thick plate with the thickness of 100 mm-180 mm, the width of 1080 mm-1480 mm and the length of 3200 mm-3300 mm, wherein the unevenness of the TA15 titanium alloy super-thick plate is less than 4mm/m, and the distance between each angle and the platform is not more than 5mm.
  2. 2. The rolling method of the large-size TA15 titanium alloy super-thick plate is characterized in that in the first step, the forging temperature of the twice beta single-phase region forging is 1050-1150 ℃, the forging ratio is 7.0-10.0, the initial forging temperature is not lower than 1000 ℃, the final forging temperature is not lower than 850 ℃, the air cooling is carried out after forging to room temperature, the forging temperature of the twice alpha+beta two-phase region forging is 920-960 ℃, the forging ratio is 4.0-7.0, the initial forging temperature is not lower than 850 ℃, the final forging temperature is not lower than 700 ℃, the forging temperature of the forming air cooling is 920-940 ℃, the initial forging temperature is not lower than 850 ℃, the final forging temperature is not lower than 700 ℃, and the air cooling is carried out after forging to room temperature.
  3. 3. The rolling method of the large-size TA15 titanium alloy super-thick plate according to claim 1 is characterized in that the specific process of heating in the step two by adopting a step heating mode is that the first step is heated at 600 ℃ for 1.5-2 h, the temperature is raised to the second step at 800 ℃ for 2-2.5 h along with the furnace at 4 ℃ per minute after the heat preservation is finished, and the temperature is raised to the third step at 920-940 ℃ along with the furnace at 3 ℃ for 3-4 h after the heat preservation is finished.
  4. 4. The rolling method of the large-size TA15 titanium alloy super-thick plate according to claim 1, wherein in the third step, the initial rolling temperature of the first rolling process is not lower than 900 ℃, the final rolling temperature is not lower than 780 ℃, the total deformation rate is 16%, the temperature of the middle of the first rolling process Cheng Gapi is not lower than 850 ℃, the temperature of the middle of the first rolling process is not higher than 250 ℃ after water cooling treatment, the total deformation rate of the reversing rolling of the two rolling processes is 40% -60%, the initial rolling temperature of the second rolling process is not lower than 900 ℃, the final rolling temperature is not lower than 820 ℃, the temperature of the middle of the second rolling process Cheng Gapi is not lower than 900 ℃, the temperature of the middle of the third rolling process is not lower than 900 ℃, the final rolling temperature is not lower than 850 ℃, the total deformation rate is 20% -30%, the temperature of the third rolling process Cheng Gapi before water cooling treatment is not lower than 850 ℃, the temperature of the middle of the second rolling process after water cooling treatment is not higher than 250 ℃, and the water cooling time is not higher than 4min.
  5. 5. The method for rolling the large-size TA15 titanium alloy super-thick plate according to claim 1, wherein the temperature of the heat treatment of the finished product in the fourth step is 750-800 ℃, the heat preservation time is 1.5-2.5 h, and the temperature of the TA15 titanium alloy rolled blank after reciprocating straightening before air cooling is not lower than 720 ℃.
  6. 6. The rolling method of the large-size TA15 titanium alloy super-thick plate according to claim 1, wherein the temperature of the shape correction treatment in the fifth step is 520-550 ℃, the heat preservation time is 5-7 h, and the air cooling is carried out to room temperature after the shape correction treatment.

Description

Rolling method of large-specification TA15 titanium alloy super-thick plate Technical Field The invention belongs to the technical field of titanium alloy plate preparation, and particularly relates to a rolling method of a large-specification TA15 titanium alloy super-thick plate. Background The nominal component of the TA15 titanium alloy is Ti-6.5Al-2Zr-1Mo-1V, and the TA15 titanium alloy has medium room temperature strength, high temperature strength, good thermal stability and welding performance, so that the TA15 finished product comprises thick plates, forgings, bars, sectional materials and the like and is widely applied to the fields of airplanes, engine parts, structural members and the like with the temperature below 500 ℃. With the rapid development of the aviation and aerospace fields, the use requirements of large-specification forgings are also increasing. However, the existing large titanium alloy forging has the following problems that firstly, the large forging is limited by equipment and is usually small in length and width, the use risk of the forging is increased due to the fact that the large forging is required to be welded, secondly, the forging is discontinuous, if the internal and external deformation degree of the blank is easy to be distributed unevenly during free forging, the organization and the performance are uneven, and in addition, the forging is required to reserve a large machining allowance for machining the surface, the production period is long, the yield is low, and mass production cannot be achieved. Therefore, with the demands of low cost on raw material cost in the aviation and aerospace fields, the thick plate can be rolled, on one hand, the thick plate can be processed into a larger size, the production efficiency is higher, and on the other hand, the yield is higher and the production cost is lower. Therefore, the advantage of using rolling to produce ultra-thick gauge plates to replace forgings is becoming more and more obvious. Disclosure of Invention The technical problem to be solved by the invention is to provide a rolling method of a large-specification TA15 titanium alloy super-thick plate aiming at the defects of the prior art. According to the method, the original beta grains are fully crushed and uniformly organized through five-fire forging, one-fire rolling of three rolling processes is performed after stepped heating, the plate blank is fully deformed, the organization and the performance are consistent through reversing rolling, the excessive growth of the grain size is restrained through rapid water cooling treatment, and then the reinforced phase precipitation is promoted through heat treatment and shape correction treatment, so that the TA15 titanium alloy super-thick plate with fine grain size, small anisotropism and excellent performance is obtained, the production efficiency is high, the cost is low, and the problems of limited size, uneven organization performance, long production period and high cost of the existing forge piece are solved. In order to solve the technical problems, the technical scheme adopted by the invention is that the rolling method of the large-specification TA15 titanium alloy super-thick plate is characterized by comprising the following steps of: Sequentially carrying out twice beta single-phase zone forging, twice alpha+beta two-phase zone forging and forming forging on a TA15 titanium alloy cast ingot to obtain a TA15 titanium alloy slab with the thickness of 300-360 mm, the width of 900-1250 mm and the length of 1500-2200 mm, wherein the TA15 titanium alloy slab meets the A1 technical requirement in GB/T5193-2020 ultrasonic inspection method of titanium and titanium alloy processed products, and the original beta grains of slab structure are fully crushed and have uniform structure; Coating the upper surface, the lower surface and the side surface of the TA15 titanium alloy plate blank obtained in the first step with an anti-oxidation coating, and then heating in a step heating mode, wherein the first step is subjected to heat preservation at 600 ℃, the temperature is raised to 800 ℃ along with a furnace after the heat preservation is finished, the temperature is raised to 920-940 ℃ along with the furnace after the heat preservation is finished; thirdly, performing primary fire rolling on the TA15 titanium alloy slab heated in the second step to obtain a TA15 titanium alloy rolled blank; the first-pass rolling is divided into three rolling passes, namely, the first rolling pass is carried out on a TA15 titanium alloy plate blank after heating, namely, the rolling pass deformation rate of one rolling pass is 5% -10%, the number of rolling passes is 2-3, the rolling speed is 3-4 m/s, the first rolling Cheng Gapi with the thickness of 250-304 mm and the width of 1500-290 mm and the length of 630-480 mm is obtained, then the first rolling Cheng Gapi is subjected to intermediate on-line furnace temperature compensatio