CN-121607407-B - Rolling method of isotropic TA22 titanium alloy sheet

CN121607407BCN 121607407 BCN121607407 BCN 121607407BCN-121607407-B

Abstract

The invention discloses a rolling method of an isotropic TA22 titanium alloy sheet, which comprises the following steps of firstly heating in a stage mode to perform first fire rolling, secondly cutting and quenching, thirdly cutting and quenching, secondly cutting and quenching, fourthly cutting, fifthly cutting and quenching, thirdly cutting and quenching, sixthly cutting and quenching, externally coating steel wrappers, seventhly coating and lapping, and eighth finishing heat treatment to obtain the TA22 titanium alloy sheet. The preparation method of the TA22 titanium alloy sheet adopts the processes of one-time rolling, quenching, two-time rolling, cladding rolling and heat treatment of finished products, combines control of rolling reversing and temperature and pass deformation rate in each rolling process, enables the sheet to be fully and uniformly deformed, adopts a furnace cooling and air cooling heat treatment mode to enable the sheet to be fully recrystallized, avoids sheet deformation caused by direct cooling after the heat treatment of the sheet, and obtains the TA22 titanium alloy sheet with fine, uniform and small structure, high size uniformity and isotropy, and is suitable for the fields of ships, machinery, chemical industry, petroleum and the like.

Inventors

FU WENJIE
ZHANG YIHENG
ZHAO ZHIWEI
LI PENG
XIE YINGJIE

Assignees

西部钛业有限责任公司

Dates

Publication Date: 20260508
Application Date: 20260130

Claims (5)

1. The rolling method of the isotropic TA22 titanium alloy sheet is characterized by comprising the following steps of: Firstly, heating a TA22 titanium alloy plate blank with the thickness of 180-200 mm, the width of 700-900 mm and the length of 900-1200 mm to 780 ℃, and then performing a first rolling process of first fire rolling at 880-910 ℃ to obtain a plate blank with the thickness of 126-138 mm, the width of 900-1200 mm and the length of 1000-1300 mm, wherein the first rolling process is unidirectional rolling, the pass deformation rate is 8-20%, the rolling rate is 1.5-3 m/s, the specific process of the first rolling process is heating to 780 ℃ and preserving heat for 1.5h, and then heating to 880-910 ℃ and preserving heat for 4-5 h for rolling, and the total deformation rate is 29-31%; Performing on-line furnace return temperature compensation, and performing a second rolling process of first fire rolling at 880-910 ℃ to obtain a first plate with the thickness of 20-25 mm, the width of 1000-1300 mm and the length of 4500-5600 mm, wherein the rolling direction of the second rolling process is perpendicular to the rolling direction of the first rolling process, the pass deformation rate is 10-25%, the rolling rate is 1.5-3 m/s, the specific process of the second rolling process is that the second rolling process is heated to 880-910 ℃ and is subjected to air cooling after being subjected to heat preservation for 1-2 hours, the total deformation rate is 81-84%, the initial rolling temperature of the first rolling process and the second rolling process is not lower than 860 ℃, and the final rolling temperature is not lower than 750 ℃; Cutting the first plate obtained in the first step, and quenching in a beta-phase region; Thirdly, performing second fire rolling on the first plate quenched in the second step at 880-910 ℃ to obtain a second plate with the thickness of 10-13 mm, the width of 1000-1300 mm and the length of 230-2900 mm, wherein the rolling direction of the second fire rolling is parallel to the rolling direction of the second rolling in the first step, the pass deformation rate is 10-25%, the rolling rate is 2-4 m/s, the specific process of the second fire rolling is that the second plate is heated to 880-910 ℃ and is subjected to heat preservation for 1-2 h, then air cooling is performed, the starting rolling temperature is not lower than 820 ℃, the final rolling temperature is not lower than 650 ℃, and the total deformation rate is 45-50%; Cutting the second plate obtained in the third step; The second plate cut in the fourth step is rolled by third fire at 860-880 ℃ to obtain a third plate with the thickness of 5-9 mm, the width of 950-640 mm and the length of 1700-190 mm, the rolling direction of the third fire rolling is perpendicular to the second fire rolling direction in the third step, the pass deformation rate is 10-25%, the rolling rate is 3-4 m/s, the specific process of the third fire rolling is that the third plate is heated to 860-880 ℃ and is air cooled after being rolled for 0.5-1h, the rolling start temperature is not lower than 800 ℃, the final rolling temperature is not lower than 720 ℃, and the total deformation rate is 30-50%; Step six, cutting the third plate obtained in the step five, and taking a plurality of stacked outer cladding steel wraps to obtain cladding rolling wraps; Step seven, unpacking the clad-laminated rolled sheet obtained in the step six after clad-laminated rolling at 880-900 ℃ to obtain a clad-laminated rolled sheet with the thickness of 1-2 mm, the width of 950-1250 mm and the length of 3000mm, wherein the rolling direction of the clad-laminated rolling is parallel to the third-fire rolling direction in the step five, the pass deformation rate is 10-20%, and the rolling speed is 2-4 m/s; and step eight, carrying out heat treatment on the finished product of the clad-rolled sheet obtained in the step seven at 780-820 ℃, and cooling to 600 ℃ in an air way to obtain the TA22 titanium alloy sheet.
2. The method for rolling the isotropic TA22 titanium alloy sheet according to claim 1, wherein the specific quenching process in the second step is that the sheet is heated to 960-980 ℃ and then is discharged from a furnace after being subjected to heat preservation for 0.5-1 h, a water tank is immersed in the discharged furnace for 5 seconds, the first sheet is continuously rocked, the water tank adopts circulating water, and the temperature of the circulating water is not more than 30 ℃.
3. The method for rolling an isotropic TA22 titanium alloy sheet according to claim 1, wherein the third plate surface after cutting is cross-coated with an anti-oxidation coating before the steel cladding in the step six, and both ends of the steel cladding and rolling cladding are provided with vent holes.
4. The method for rolling the isotropic TA22 titanium alloy sheet according to claim 1, wherein the specific process of the cladding and rolling in the seventh step is that the cladding and rolling are carried out by heating to 880-900 ℃ and preserving heat for 1-2 h, then air cooling is carried out, the initial rolling temperature is not lower than 850 ℃, the final rolling temperature is not lower than 650 ℃, and the total deformation rate is 77% -80%.
5. The method for rolling the isotropic TA22 titanium alloy sheet according to claim 1, wherein the specific process of the heat treatment of the finished product in the eighth step is heating to 780-820 ℃, preserving heat for 60-90 min, cooling to 600 ℃ for 60min, and discharging and air cooling.

Description

Rolling method of isotropic TA22 titanium alloy sheet Technical Field The invention belongs to the technical field of titanium and titanium alloy sheet preparation, and particularly relates to a rolling method of an isotropic TA22 titanium alloy sheet. Background The nominal component (%), by mass fraction, of the TA22 titanium alloy is Ti-3Al-1Mo-1Ni-2Zr, belonging to the low alloyed near alpha titanium alloy. The TA22 titanium alloy has medium strength, high plasticity, good processability and formability, excellent corrosion resistance and weldability, and is a novel high-temperature corrosion-resistant titanium alloy. At present, the conventional thickness of the TA22 sheet material is 4-30 mm, and the performance requirement of the conventional thickness of the TA22 sheet material in the specification of the titanium and titanium alloy sheet material for ships (GJB 944A-2018) is that the transverse room temperature tensile strength is more than or equal to 635MPa, the yield strength is more than or equal to 490MPa, and the elongation after break is more than or equal to 17%. While TA22 titanium alloy sheet (thickness <4 mm) has been relatively less studied and has not yet been produced in a stabilized manner. According to the production experience of near alpha titanium alloy wave plates, the TA22 titanium alloy sheet is generally prepared by adopting a hot rolling (reversing) +cold rolling mode. The test-made result shows that the plate needs four hot rolling times and one or two cold rolling times, the production flow is longer, the production efficiency is lower, and in addition, the difference of transverse and longitudinal properties of the test-made plate is larger (the difference of room temperature tensile strength is about 35MPa, and the difference of yield strength is about 50 MPa). Therefore, technical improvement is needed, and a TA22 titanium alloy sheet process route with high production efficiency and good isotropy is developed. Disclosure of Invention The invention aims to overcome the defects in the prior art and provide a rolling method of an isotropic TA22 titanium alloy sheet. The preparation method comprises the steps of carrying out stepwise heating on a first hot rolling process to avoid abnormal growth of internal grains caused by long-time heating of a plate blank, carrying out one-hot rolling, quenching, two-hot rolling and cladding and rolling processes, controlling the temperature and the pass deformation rate in the rolling reversing and rolling processes in a combined mode to enable the plate to be fully and uniformly deformed, and finally carrying out heat treatment on a finished product combined by furnace cooling and air cooling to obtain the TA22 titanium alloy thin plate with fine and uniform structure, high size uniformity and high isotropy, thereby solving the problems of long production flow, lower production efficiency and large mechanical property difference of the conventional TA22 titanium alloy thin plate. In order to achieve the purpose, the technical scheme adopted by the invention is that the method for rolling the isotropic TA22 titanium alloy sheet is characterized by comprising the following steps of: Firstly, heating a TA22 titanium alloy slab with the thickness of 180 mm-200 mm, the width of 700 mm-900 mm and the length of 900 mm-1200 mm to 780 ℃, and then performing a first rolling process of first hot rolling at 880-910 ℃ to obtain a slab with the thickness of 126 mm-138 mm, the width of 900 mm-1200 mm and the length of 1000 mm-1300 mm, wherein the first rolling process is unidirectional rolling, the pass deformation rate is 8% -20%, and the rolling rate is 1.5 m/s-3 m/s; performing on-line furnace return temperature compensation, and performing a second rolling process of first hot rolling at 880-910 ℃ to obtain a first plate with the thickness of 20-25 mm, the width of 1000-1300 mm and the length of 4500-5600 mm, wherein the rolling direction of the second rolling process is perpendicular to the rolling direction of the first rolling process, the pass deformation rate is 10-25%, and the rolling rate is 1.5-3 m/s; Cutting the first plate obtained in the first step, and quenching in a beta-phase region; Thirdly, performing second fire rolling on the quenched first plate at 880-910 ℃ to obtain a second plate with the thickness of 10-13 mm, the width of 1000-630 mm and the length of 2300-2900 mm, wherein the rolling direction of the second fire rolling is parallel to the rolling direction of the second rolling in the first step, the pass deformation rate is 10-25%, and the rolling speed is 2-4 m/s; Cutting the second plate obtained in the third step; step five, rolling the second plate cut in the step four at 860-880 ℃ for a third fire time to obtain a third plate with the thickness of 5-9 mm, the width of 950-640 mm and the length of 1700-190 mm, wherein the rolling direction of the third fire time rolling is perpendicular to the rolling direction of