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CN-122007299-A - Preparation method of high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering

CN122007299ACN 122007299 ACN122007299 ACN 122007299ACN-122007299-A

Abstract

A preparation method of a high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering relates to a preparation method of a titanium alloy forging. The invention aims to solve the problem that the existing titanium alloy has unmatched toughness. According to the invention, through high-temperature large-deformation forging processing and reduction of forging fire, and combining with a two-phase zone annealing treatment process, tissue uniformity and high strength-high toughness matching are realized at low temperature, so that good toughness matching is obtained at low temperature for the titanium alloy forging, excellent strength is achieved, meanwhile, good toughness is achieved, a novel manufacturing method is provided for development of the titanium alloy forging with toughness matching for ocean engineering, and the usability of the Ti80 titanium alloy material is greatly expanded. And the forging period and the cost are obviously reduced, the process controllability is enhanced, and the requirements of the high-strength and high-toughness titanium alloy forgings for ocean engineering are met.

Inventors

  • XU CHAO
  • Cong shuanglong
  • WANG YANPU
  • ZUO JING
  • WU ZELIN
  • CHEN WENHAO
  • FENG WEIWEI
  • ZHAO TIANTIAN
  • ZHAO DELI
  • NIE YIHONG
  • ZHU LIN
  • LU ZHEN
  • ZHANG XU
  • CHEN JIALUO
  • DING HAOYANG

Assignees

  • 哈尔滨工业大学

Dates

Publication Date
20260512
Application Date
20260319

Claims (10)

  1. 1. The preparation method of the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering is characterized by comprising the following steps of: 1. homogenizing heat treatment is carried out on the forged raw material of the Ti80 titanium alloy; The temperature of the homogenizing heat treatment is 1100-1200 ℃, and the heat preservation time is 40min-12 hours; 2. removing an oxide layer on the surface of the raw material subjected to the homogenization heat treatment in the first step, and then upsetting and forging to obtain a blank; The upsetting forging process comprises the steps of heating raw materials to a forging temperature and preserving heat for 40min, and then upsetting forging, wherein the height reduction of upsetting forging is 60%, and the forging temperature is 900-980 ℃; 3. Tempering the blank obtained in the second step; The tempering treatment is carried out at 900-980 ℃ for 20min; 4. Forging the forging stock obtained in the step three to obtain a titanium alloy forging; the forming forging process comprises the steps of forging at 900-980 ℃, keeping the temperature for t=0.4H, wherein the unit is min, H is the height of a forging stock, t is mm, and the deformation of the forging is 30%; 5. carrying out alpha+beta two-phase zone annealing heat treatment on the titanium alloy forging obtained in the step four; the annealing heat treatment process of the alpha+beta two-phase region comprises the steps of heat treatment at a temperature of 30-50 ℃ below the phase transition point and heat preservation for 1-2 hours.
  2. 2. The method for producing a high strength and toughness Ti80 titanium alloy forging for low temperature ocean engineering according to claim 1, wherein in the step one, the Ti80 titanium alloy contains 5.42-5.6wt.% of Al element, 2.69-3.83wt.% of Nb element, 1.91-2.04wt.% of Zr element, 1.35-1.48wt.% of Mo element, and the balance of Ti.
  3. 3. The method for manufacturing a high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering according to claim 2, wherein in the step one, the content of Al element in the Ti80 titanium alloy is 5.40wt.%, the content of Nb element is 2.71wt.%, the content of Zr element is 1.91wt.%, the content of Mo element is 1.34wt.%, the balance is Ti, and the phase transition point temperature T β = 1030 ℃.
  4. 4. The method for manufacturing a high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering according to claim 2, wherein in the step one, the content of Al element in the Ti80 titanium alloy is 5.60wt.%, the content of Nb element is 2.83wt.%, the content of Zr element is 2.04wt.%, the content of Mo element is 1.41wt.%, the balance is Ti, and the phase transition point temperature T β = 1032 ℃.
  5. 5. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering according to claim 1, wherein the temperature of the homogenizing heat treatment in the step one is 1100 ℃, and the heat preservation time is 40min.
  6. 6. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering according to claim 1, wherein the upsetting forging process is characterized in that the raw material is heated to 980 ℃ and kept for 40min, then upsetting forging is carried out, and the height reduction of the upsetting forging is 60%.
  7. 7. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering according to claim 1, wherein the tempering treatment in the step three is carried out at 980 ℃ for 20min.
  8. 8. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering according to claim 1, wherein the forming forging process is characterized in that the forging temperature is 980 ℃, the heat preservation time is t=0.4H, H is the height of a forging stock, H is 80mm, t is min, and the deformation of the forging is 30%.
  9. 9. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering according to claim 1, wherein the cooling mode of the annealing heat treatment of the alpha+beta two-phase region in the step five is air cooling.
  10. 10. The method for preparing the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering according to claim 1, wherein the annealing heat treatment process of the alpha+beta two-phase region is carried out in the fifth step, the heat treatment temperature is 980 ℃, and the heat preservation time is 1.5 hours.

Description

Preparation method of high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering Technical Field The invention relates to a preparation method of a titanium alloy forging. Background Deep sea is a strategic resource treasury developed by human beings, and surrounds the fields of ocean engineering, ocean resources, ocean environments and the like. The deep sea diving device has higher requirements on the strength and the plasticity of materials. Under the deep sea environment, the metal material generally faces a series of problems such as sharp reduction of toughness, increase of brittle transition temperature, ductile-brittle transition of fracture mode and the like, and sudden and unwarranted catastrophic damage of the structural member in the service process is often caused. Therefore, the development and selection of materials with excellent low-temperature toughness and stable mechanical response are basic preconditions and core technical requirements in the key fields of deep sea engineering, polar exploration, low-temperature propulsion systems, aerospace low-temperature energy storage equipment and the like. Under low temperature conditions, metallic materials are often prone to embrittlement and cause catastrophic accidents. Therefore, to prevent material failure at low temperatures, the selection of materials with excellent low temperature toughness has become an important prerequisite for low temperature load bearing applications. The large-specification near-alpha titanium alloy forging is widely applied to the fields of deep sea pressure-resistant structures, aviation bearing components and high-reliability equipment, and the service performance of the large-specification near-alpha titanium alloy forging is directly related to the safety and structural integrity of the equipment in extreme environments. In the strengthening process of the titanium alloy material, the strength and the toughness often show the phenomenon of unmatched toughness of the titanium alloy material. While the strength is improved, the internal slip of the titanium alloy material is limited, the defect sensitivity is increased, the local stress concentration and microcrack expansion are easy to cause the remarkable reduction of toughness, and when the high toughness is pursued, the strength is usually sacrificed by weakening a strengthening mechanism and improving the deformation coordination, namely 'strength-toughness mismatch', the contradiction is particularly prominent at low temperature of structural materials such as titanium alloy, and the single strengthening means is difficult to simultaneously combine the high strength and the high toughness, so that the service reliability of the titanium alloy material under extreme working conditions is restricted. Therefore, how to perform microstructure regulation and control through a forging process, break the inversion relation between strength and toughness, realize the cooperative promotion of toughness, and are key research directions of current material modification and engineering application. Disclosure of Invention The invention provides a preparation method of a high-strength and high-toughness Ti80 titanium alloy forging for low-temperature ocean engineering, aiming at the problem that the existing titanium alloy has unmatched strength and toughness. The preparation method of the high-strength and high-toughness Ti80 titanium alloy forging for the low-temperature ocean engineering comprises the following steps: 1. homogenizing heat treatment is carried out on the forged raw material of the Ti80 titanium alloy; The temperature of the homogenizing heat treatment is 1100-1200 ℃, and the heat preservation time is 40min-12 hours; 2. removing an oxide layer on the surface of the raw material subjected to the homogenization heat treatment in the first step, and then upsetting and forging to obtain a blank; The upsetting forging process comprises the steps of heating raw materials to a forging temperature and preserving heat for 40min, and then upsetting forging, wherein the height reduction of upsetting forging is 60%, and the forging temperature is 900-980 ℃; 3. Tempering the blank obtained in the second step; The tempering treatment is carried out at 900-980 ℃ for 20min; 4. Forging the forging stock obtained in the step three to obtain a titanium alloy forging; The forming forging process comprises the steps of forming forging under a transformation point, wherein the forging temperature is 900-980 ℃, the heat preservation time is t=0.4H, the unit is min, H is the height of a forging stock, the unit of t is mm, and the forging deformation is 30%; 5. carrying out alpha+beta two-phase zone annealing heat treatment on the titanium alloy forging obtained in the step four; the annealing heat treatment process of the alpha+beta two-phase region comprises the steps of heat treatment at a temperature of 30-50 ℃ below the phase transi