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CN-122012987-A - Titanium alloy seamless tube and preparation method thereof

CN122012987ACN 122012987 ACN122012987 ACN 122012987ACN-122012987-A

Abstract

The invention discloses a titanium alloy seamless pipe and a preparation method thereof. The chemical composition of the titanium alloy seamless tube comprises ：Al：5%~6.5%,Mo：1.5%~3%,V：1.5%~2%,Zr：3%~4%,Sn：2.5%~3.6%,Nb：0.5%~1.5%,Si：0.2%~0.5%,B：0.4%~0.6%,Ce：0.8%~1.2%, percent of Ti and other unavoidable impurity elements in percentage by mass. The preparation method comprises the working procedures of smelting titanium alloy, casting a tube blank, forging, heat treatment and cold rolling. The titanium alloy seamless pipe optimizes the components and regulates the proportion of each element on the basis of TA15 alloy, and is added with B, ce elements in a specific proportion, the preparation method is suitable for the titanium alloy components, so that the structural uniformity and the surface quality of the pipe are improved, and the prepared titanium alloy seamless pipe has the excellent performances of high strength and high toughness.

Inventors

  • KANG QIN
  • SU HAO
  • WU JINGYI
  • ZHONG YONG

Assignees

  • 攀钢集团攀枝花钢铁研究院有限公司
  • 成都先进金属材料产业技术研究院股份有限公司

Dates

Publication Date
20260512
Application Date
20260303

Claims (10)

  1. 1. A titanium alloy seamless tube, characterized in that the chemical composition of the titanium alloy seamless tube comprises ：Al：5%~6.5%,Mo：1.5%~3%,V：1.5%~2%,Zr：3%~4%,Sn：2.5%~3.6%,Nb：0.5%~1.5%,Si：0.2%~0.5%,B：0.4%~0.6%,Ce：0.8%~1.2%, the balance of Ti and other unavoidable impurity elements in mass percent.
  2. 2. The preparation method of the titanium alloy seamless tube is characterized by comprising the following steps of: Step S101, raw materials are proportioned according to chemical compositions, and the raw materials are smelted to obtain a titanium alloy hollow tube blank and are subjected to surface treatment; Step S102, uniformly spraying protective lubricating layers on the inner surface and the outer surface of the titanium alloy hollow tube blank processed in the step S101, and then heating, wherein the heating process is to heat at a heating speed of 600 ℃ per hour when heating each time, and firstly preserving heat for 2 hours at 60-100 ℃ below a phase transition point, and then continuously heating to a forging temperature; Step 103, performing radial forging on the titanium alloy hollow tube blank heated in the step 102, wherein five-pass radial forging is adopted, the forging temperature of each pass is gradually reduced, the last forging is performed by adopting an arc anvil, the pass reduction is 10% -20% during forging, the diameter of a core rod is smaller than the inner diameter of the intermediate tube blank in the previous time by 4% -6 mm, the feeding amount is 100% -200 mm, the blank is rotated for 90 degrees for continuous forging after each pass of forging, and the forging is repeatedly performed until the target specification is reached, and then air cooling is performed to the room temperature; And step S104, sequentially performing heat treatment and cold rolling on the titanium alloy tube obtained in the step S103 to form the titanium alloy seamless tube.
  3. 3. The method for producing a seamless titanium alloy tube according to claim 2, wherein in step S102, "continuing to raise the temperature to the forging temperature" includes holding the temperature for 1 hour at a temperature of 30 ℃ below the transformation point to 200 ℃ above the transformation point, and then discharging the tube from the furnace for subsequent radial forging.
  4. 4. The method of producing a titanium alloy seamless pipe according to claim 2, wherein in step S101, the raw materials are titanium sponge, baked TiO 2 powder, vanadium-aluminum alloy, aluminum-molybdenum, zirconium sponge, a tin-niobium-containing intermediate alloy, and cerium hexaboride; the chemical composition comprises ：Al：5%~6.5%,Mo：1.5%~3%,V：1.5%~2%,Zr：3%~4%,Sn：2.5%~3.6%,Nb：0.5%~1.5%,Si：0.2%~0.5%,B：0.4%~0.6%,Ce：0.8%~1.2%, percent by mass of Ti and other unavoidable impurity elements; The smelting process is to adopt a vacuum electron beam cold hearth furnace or a vacuum plasma cold hearth furnace to carry out primary smelting to obtain primary cast ingots, then use the vacuum plasma cold hearth furnace to carry out secondary smelting, and cast and mold the titanium alloy liquid obtained by the secondary smelting to obtain the titanium alloy hollow tube blank.
  5. 5. The method for producing a titanium alloy seamless pipe according to claim 2, wherein in step S101, the surface treatment polishes the outer surface of the titanium alloy hollow shell, and boring the inner hole to the inner and outer surfaces without defects, thereby obtaining the titanium alloy hollow shell having both the inner and outer surfaces in a white and bright state.
  6. 6. The method of producing a titanium alloy seamless pipe according to claim 2, wherein in step S102, the protective lubricant layer is a glass protective lubricant.
  7. 7. The method for manufacturing the titanium alloy seamless tube according to claim 2 is characterized in that in the step S103, the diameter of a mandrel is smaller than the inner diameter of a tube blank by 6-10 mm in the first radial forging, the radial pressing-in amount of each hammer is 15-25 mm, the axial feeding speed is 2.5-3 m/min, the revolution of the tube blank is 25-40 r/min, the hammering speed is 1500-2000 times/min, the integral deformation amount is 40% -60%, the diameter of the mandrel is smaller than the inner diameter of a middle tube blank obtained in the previous radial forging by the second and third radial forging, the radial pressing-in amount of each hammer is 20-30 mm, the axial feeding speed is 2.5-3 m/min, the revolution of the tube blank is 25-40 r/min, the hammering speed is 2000-2500 times/min, the integral deformation amount is 60% -70%, the diameter of the mandrel is smaller than the inner diameter of the middle tube blank obtained in the previous radial forging by the fourth radial forging, the radial pressing-in amount of each hammer is 10-15 mm, the axial feeding speed is 2.5-3 m/min, the integral deformation amount is 25-40 r/min, the radial rolling-2000 min, and the radial deformation amount of each hammer is ensured to be at the final deformation point of 100 ℃ at the temperature of 100 ℃.
  8. 8. The method for manufacturing the titanium alloy seamless tube according to claim 2, wherein in the step S103, the arc-shaped anvil comprises an upper anvil and a lower anvil which are arranged vertically symmetrically, the upper anvil and the lower anvil comprise a main body with arc grooves, two sides of each arc groove are respectively provided with a section of straight inclined surface, the straight inclined surfaces are connected with a horizontal section, the radius R of each arc groove is the outer diameter+ (30 mm-60 mm) of a forged finished tube, the included angle phi of a tangent line of a connecting point of each straight inclined surface and each arc groove is 15-25 degrees, the length of the main body is 150-300 mm, and the width of the main body is 150-300 mm.
  9. 9. The method according to claim 2, wherein in step S104, the heat treatment is performed by two heat treatments, i.e., heat treatment and aging treatment, wherein the heat treatment is performed by air cooling to room temperature after heat preservation for 2 hours at 30 ℃ below the transformation point, then air cooling to room temperature after heat preservation for 6 hours at 600 ℃ again.
  10. 10. The method according to claim 2, wherein in step S104, the cold rolling step is performed by performing multiple passes of cold rolling, degreasing, removing defects on the inner and outer surfaces, pickling, annealing, straightening, pickling, and flaw detection on the titanium alloy tube.

Description

Titanium alloy seamless tube and preparation method thereof Technical Field The invention belongs to the technical field of titanium alloy pipe manufacturing, and particularly relates to a titanium alloy seamless pipe and a preparation method thereof. Background Titanium and titanium alloy have wide application in the fields of aerospace, medical equipment, chemical industry and the like due to the excellent performances of low density, high strength, corrosion resistance and the like, wherein the titanium alloy seamless pipe has larger and larger application market by virtue of the performance advantages, and is widely applied to industries of petroleum, gas, thermal power generation, nuclear power, aerospace and the like. At present, the traditional preparation flow of the titanium alloy seamless pipe comprises the steps of preparing a bar blank from a titanium alloy cast ingot after multiple smelting through multiple times of forging, preparing the bar blank into a pipe blank through hot rolling perforation or drilling and hot extrusion, preparing a finished product through a series of hot rolling, cold rolling, finishing and other processes, and carrying out auxiliary processes such as multiple times of heat treatment, acid washing, sand blasting, machining and the like in the middle. The conventional titanium alloy tube preparation process has many defects, a bar blank is obtained by forging with multiple fires, the conventional titanium alloy forging process is limited by equipment capacity and forging technology, the uniformity of the structure performance of the forging blank is poor, the problems of unstable material core and surface performance and the like exist, the subsequent processing and using requirements of the material cannot be met, the hot rolling perforation process has the defects that the structure of the tube blank is basically basket structure or Wittig structure due to higher processing temperature, the processing performance is poor, cracks are easy to form in the perforation process, the subsequent processing and using requirements of the material cannot be met, and when the tube blank is prepared by drilling and hot extrusion, the equipment cost is high, the energy consumption is high, compared with the cold extrusion or other processing methods, the production flexibility is poor, the surface quality is difficult to control, and pollutants such as waste gas and waste water generated in the production process can also pollute the environment. Among the near alpha titanium alloys, the TA15 alloy is a Ti-Al-Zr-Mo-V medium strength titanium alloy, has good welding performance and plasticity and excellent comprehensive performance, is mainly used for the titanium alloy for the aircraft frame, and has room for further improving the strength and the plasticity of the TA15 titanium alloy along with the development trend of light aircraft weight. Therefore, in order to overcome the shortcomings in the above technical aspects, it is necessary to develop a high-strength titanium alloy, and to optimize and improve the conventional titanium alloy pipe production process technology, so as to quickly, efficiently and inexpensively prepare a high-performance high-strength high-toughness titanium alloy seamless pipe. Disclosure of Invention Based on the above, in order to make up the defects of the prior art, a titanium alloy seamless tube and a preparation method thereof are provided. In order to achieve the above purpose, the following technical scheme is adopted: The invention provides a titanium alloy seamless pipe, which comprises the following chemical components in percentage by mass, wherein the balance of ：Al：5%~6.5%,Mo：1.5%~3%,V：1.5%~2%,Zr：3%~4%,Sn：2.5%~3.6%,Nb：0.5%~1.5%,Si：0.2%~0.5%,B：0.4%~0.6%,Ce：0.8%~1.2%, is Ti and other unavoidable impurity elements. The invention also provides a preparation method of the titanium alloy seamless pipe, which comprises the following steps: Step S101, raw materials are proportioned according to chemical compositions, and the raw materials are smelted to obtain a titanium alloy hollow tube blank and are subjected to surface treatment; Step S102, uniformly spraying protective lubricating layers on the inner surface and the outer surface of the titanium alloy hollow tube blank processed in the step S101, and then heating, wherein the heating process is to heat at a heating speed of 600 ℃ per hour when heating each time, and firstly preserving heat for 2 hours at 60-100 ℃ below a phase transition point, and then continuously heating to a forging temperature; Step 103, performing radial forging on the titanium alloy hollow tube blank heated in the step 102, wherein five-pass radial forging is adopted, the forging temperature of each pass is gradually reduced, the last forging is performed by adopting an arc anvil, the pass reduction is 10% -20% during forging, the diameter of a core rod is smaller than the inner diameter of the intermediate tube blank i