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CN-122012988-A - 1500 MPa-grade TB9 titanium alloy bar and preparation method thereof

CN122012988ACN 122012988 ACN122012988 ACN 122012988ACN-122012988-A

Abstract

The invention discloses a 1500 MPa-level TB9 titanium alloy bar and a preparation method thereof, wherein the preparation method comprises the following steps of 1, selecting a TB9 titanium alloy forged bar, wherein different elements of the forged bar meet a control range, 2, heating and rolling, namely heating the forged bar in the step 1 to 750-850 ℃ in a rolling heating furnace, then rolling the forged bar to a rolled bar with the diameter of phi 21-phi 54.2mm, 3, carrying out solution treatment, namely heating the rolled bar prepared in the step 2 to 750-800 ℃ in a heat treatment furnace, carrying out heat preservation for 30-75 min, 4, carrying out cold forging or cold drawing on the bar prepared in the step 3 to obtain a bar with the diameter of phi 16.5-phi 42mm, and 5, carrying out cold straightening, peeling and polishing on the cold-processed bar prepared in the step 4 to obtain a finished bar with the diameter of phi 15-phi 40 mm. The TB9 titanium alloy bar prepared by the method has good batch stability, the grain size is more than 6 grade, the tensile strength after aging is more than 1500MPa, and the elongation is more than 10%.

Inventors

  • LIU XIANGHONG
  • SHI QI
  • MA HAN
  • WANG DONGBIN
  • Qiao Jizhu
  • DU YUJUN
  • WANG TAO
  • DU YUXUAN
  • FENG YONG

Assignees

  • 西部超导材料科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260309

Claims (9)

  1. 1. A1500 MPa-level TB9 titanium alloy bar is characterized by comprising, by weight, 3.0% -4.0% of Al element, 7.5% -8.5% of V element, 5.5% -6.5% of Cr element, 3.5% -4.5% of Mo element, 3.5% -4.5% of Zr element, less than or equal to 0.05% of C element, less than or equal to 0.03% of N element, less than or equal to 0.02% of H element, less than or equal to 0.12% of impurity element Fe element, less than or equal to 0.10% of O element, and the bar has a specification of phi 15 mm-phi 40mm.
  2. 2. The method for preparing a 1500 MPa-grade TB9 titanium alloy bar according to claim 1, comprising the following steps: Step 1, preparing a bar blank: selecting a TB9 titanium alloy forging bar blank, wherein different elements of the bar blank meet a control range; step 2, heating and rolling: placing the forged bar blank in the step 1 into a rolling heating furnace, heating to 750-850 ℃, and then rolling to a rolled bar with phi 21-phi 54.2 mm; Step 3, solution treatment: Heating the rolled bar prepared in the step 2 to 750-800 ℃ in a heat treatment furnace, and preserving heat for 30-75 min; step 4, cold working: Carrying out cold forging or cold drawing on the bar material prepared in the step 3 to obtain a cold-working bar material with the diameter of phi 16.5 mm-phi 42 mm; step 5, straightening and finishing the finished bar: and (3) carrying out cold straightening, peeling and polishing on the cold-processed bar prepared in the step (4) to obtain a finished bar with the diameter of phi 15 mm-phi 40 mm.
  3. 3. The method for preparing a 1500 MPa-level TB9 titanium alloy bar according to claim 2, wherein in the step 1, the forged bar is composed of 3.0-4.0% by weight of Al, 7.5-8.5% by weight of V, 5.5-6.5% by weight of Cr, 3.5-4.5% by weight of Mo, 3.5-4.5% by weight of Zr, less than or equal to 0.05% by weight of C, less than or equal to 0.03% by weight of N, less than or equal to 0.02% by weight of H, less than or equal to 0.12% by weight of Fe, and less than or equal to 0.10% by weight of O.
  4. 4. The method for preparing a 1500 MPa-level TB9 titanium alloy bar according to claim 2, wherein in the step 1, the forged bar is of a gauge Φ165mm to Φ185mm.
  5. 5. The method for preparing a 1500 MPa-level TB9 titanium alloy bar according to claim 2, wherein in step 2, the rolling furnace is a step-type or box-type resistance furnace.
  6. 6. The method for preparing a 1500 MPa-grade TB9 titanium alloy bar according to claim 2, wherein in the step 2, the rolling apparatus adopts a two-roll reversing mill, and the pass is a rhombic-square-elliptic-round hole type system.
  7. 7. The method for preparing a 1500 MPa-grade TB9 titanium alloy bar according to claim 2, wherein in the step 2, the finishing temperature is 650 ℃ to 720 ℃, and the rolling deformation is 89.2% to 98.7%.
  8. 8. The method for preparing a 1500 MPa-level TB9 titanium alloy bar according to claim 2, wherein in the step 4, the cold working pass deformation is 8% -20% and the total deformation is 30% -40%.
  9. 9. The method for producing 1500 MPa-grade TB9 titanium alloy bars according to claim 2, wherein in step 5, the cold straightening is performed by a roll type.

Description

1500 MPa-grade TB9 titanium alloy bar and preparation method thereof Technical Field The invention belongs to the technical field of titanium alloy processing, and particularly relates to a 1500 MPa-level TB9 titanium alloy bar and a preparation method thereof. Background TB9 (Ti 38644), which was successfully developed by the American RMI company at the end of the 60 th century, is a typical metastable beta-type titanium alloy with good cold workability in the solid solution state and can be strengthened by cold working and heat treatment. The alloy has good cold and hot formability, high specific strength, high corrosion resistance, high heat treatment performance and other excellent comprehensive properties, can be processed into products such as plates, bars, wires and the like, and has wide application in the fields of aerospace, automobiles and the like. TB9 titanium alloy high-strength metastable beta titanium alloy is commonly used as an ideal material for preparing self-plugging rivet core rods in China, and a preparation method of a wire rod or a small-specification bar with the diameter of phi 2 mm-phi 15mm is commonly reported in China, wherein the time-efficiency state strength can reach more than 1300 MPa. However, a preparation method of a 1500MPa grade TB9 titanium alloy bar with the specification of phi 15mm to phi 40mm has been reported recently in China. On one hand, the difficulty of high-strength TB9 titanium alloy strong plastic matching is high, and on the other hand, the problems of large-specification TB9 bar grain refinement and cold working industrial preparation are related. Disclosure of Invention The invention aims at a 1500 MPa-level TB9 titanium alloy bar and a preparation method thereof, and the prepared TB9 titanium alloy bar has good batch stability, grain size of more than 6 levels, tensile strength of more than 1500MPa after aging and elongation of more than 10%. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: 1500 MPa-level TB9 titanium alloy bar comprises, by weight, 3.0% -4.0% of Al element, 7.5% -8.5% of V element, 5.5% -6.5% of Cr element, 3.5% -4.5% of Mo element, 3.5% -4.5% of Zr element, less than or equal to 0.05% of C element, less than or equal to 0.03% of N element, less than or equal to 0.02% of H element, less than or equal to 0.12% of impurity element Fe element, less than or equal to 0.10% of O element, and the bar has a specification of phi 15 mm-phi 40mm. Preferably, the preparation method of the 1500 MPa-level TB9 titanium alloy bar comprises the following steps: Step 1, preparing a bar blank: selecting a TB9 titanium alloy forging bar blank, wherein different elements of the bar blank meet a control range; step 2, heating and rolling: placing the forged bar blank in the step 1 into a rolling heating furnace, heating to 750-850 ℃, and then rolling to a rolled bar with phi 21-phi 54.2 mm; Step 3, solution treatment: Heating the rolled bar prepared in the step 2 to 750-800 ℃ in a heat treatment furnace, and preserving heat for 30-75 min; step 4, cold working: Carrying out cold forging or cold drawing on the bar material prepared in the step 3 to obtain a cold-working bar material with the diameter of phi 16.5 mm-phi 42 mm; step 5, straightening and finishing the finished bar: and (3) carrying out cold straightening, peeling and polishing on the cold-processed bar prepared in the step (4) to obtain a finished bar with the diameter of phi 15 mm-phi 40 mm. Preferably, in the step 1, the forging rod blank comprises 3.0-4.0% of Al element, 7.5-8.5% of V element, 5.5-6.5% of Cr element, 3.5-4.5% of Mo element, 3.5-4.5% of Zr element, less than or equal to 0.05% of C element, less than or equal to 0.03% of N element, less than or equal to 0.02% of H element, less than or equal to 0.12% of impurity element Fe element and less than or equal to 0.10% of O element. Preferably, in the step 1, the specification of the forged bar blank is phi 165mm to phi 185mm. Preferably, in the step 2, the rolling heating furnace is a step-type or box-type resistance heating furnace. Preferably, in the step 2, the rolling equipment adopts a two-roll reversible rolling mill, and the hole type is a rhombic-square-elliptic-round hole type system. Preferably, in the step 2, the finishing temperature is 650 ℃ to 720 ℃, and the rolling deformation is 89.2% -98.7%. Preferably, in the step 4, the deformation amount of the cold working pass is 8% -20%, and the total deformation amount is 30% -40%. Preferably, in the step 5, the cold straightening is performed by a roll type. The invention has the beneficial effects that: (1) The control range of the TB9 titanium alloy with lower Fe and O elements is designed, and the bar blank with uniform tissue composition and low impurity elements is obtained. The bar tissue is thinned through low-temperature rolling and process temperature control. And through the matching design of the solution treatm