CN111286686B - Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure - Google Patents

Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure Download PDF

Info

Publication number
CN111286686B
CN111286686B CN202010272116.6A CN202010272116A CN111286686B CN 111286686 B CN111286686 B CN 111286686B CN 202010272116 A CN202010272116 A CN 202010272116A CN 111286686 B CN111286686 B CN 111286686B
Authority
CN
China
Prior art keywords
forging
titanium alloy
bar
temperature
primary
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202010272116.6A
Other languages
Chinese (zh)
Other versions
CN111286686A (en
Inventor
侯智敏
王兴
杨健
吴晓东
张智
康聪
李维
杨佩
李进元
任利娜
欧阳文博
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
WESTERN TITANIUM TECHNOLOGIES CO LTD
Original Assignee
WESTERN TITANIUM TECHNOLOGIES CO LTD
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by WESTERN TITANIUM TECHNOLOGIES CO LTD filed Critical WESTERN TITANIUM TECHNOLOGIES CO LTD
Priority to CN202010272116.6A priority Critical patent/CN111286686B/en
Publication of CN111286686A publication Critical patent/CN111286686A/en
Application granted granted Critical
Publication of CN111286686B publication Critical patent/CN111286686B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/16—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of other metals or alloys based thereon
    • C22F1/18—High-melting or refractory metals or alloys based thereon
    • C22F1/183—High-melting or refractory metals or alloys based thereon of titanium or alloys based thereon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
    • B21J1/02—Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough
    • B21J1/025—Preliminary treatment of metal stock without particular shaping, e.g. salvaging segregated zones, forging or pressing in the rough affecting grain orientation
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/002—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working by rapid cooling or quenching; cooling agents used therefor

Abstract

The invention discloses a short-process preparation method of a TC4 titanium alloy thin equiaxial large-size bar, which comprises the following steps: firstly, cogging and forging a TC4 titanium alloy ingot by using a large-tonnage press, and air-cooling to obtain a primary forging stock; secondly, upsetting and drawing the primary forging stock by using a large-tonnage press, and quickly cooling to room temperature to obtain an intermediate forging stock; thirdly, performing primary radial forging on the intermediate forging stock by using a large-tonnage precision forging machine to obtain a finished radial forged bar; and fourthly, carrying out annealing heat treatment on the finished radial forged bar to obtain the large-size TC4 titanium alloy bar with the fine-grained structure. The invention adopts the process of 'hot forging blank by a large-tonnage press and radial forming by a large-tonnage precision forging machine', so that the crystal grains are fully crushed and refined, the crystal grain refining efficiency is improved, the forging heat number is obviously reduced, the preparation flow is shortened, the production cost is reduced, and the yield of the TC4 titanium alloy bar is improved.

Description

Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure
Technical Field
The invention belongs to the technical field of titanium alloy material processing, and particularly relates to a short-process preparation method of a TC4 titanium alloy thin equiaxial large-size bar.
Background
The titanium alloy has the excellent characteristics of low density, high specific strength, corrosion resistance, high temperature resistance and the like, is an ideal structural material, and plays an extremely important role in the development of national defense high technology, weaponry and civil industries. The TC4 titanium alloy has the excellent characteristics of simple components, good machinability, high specific strength, good toughness and matching, long-term use at 400 ℃, and the like, and is the most widely applied structural titanium alloy at present. Compared with steel blades, the titanium alloy blade for the aero-engine and the gas turbine has the advantages that the weight reduction effect is obvious, the power consumption efficiency of the aero-engine or the gas turbine can be obviously improved, and the energy utilization rate is improved. As a high-speed rotor, extremely high demands are made on the consistency of the structure properties and fatigue properties of the TC4 blades, particularly on the high cycle fatigue properties. Because the equiaxed structure, particularly the fine equiaxed structure has good strong plastic matching and the optimal high cycle fatigue performance, extremely strict requirements are put on the TC4 titanium alloy bar of the forging blade, and the primary equiaxed alpha phase grain size rating is required to be not less than 8 grades (less than or equal to 22.5 mu m) of GB/T6394. With the development of the aviation industry and the gas turbine industry, large-size small equiaxial bars with the diameter phi of more than or equal to 200mm are required to be prepared. In order to prepare the high-quality TC4 titanium alloy bar meeting the technical requirements, the conventional hot forging forming process comprises the following steps: 2-4 times of firing forging in a beta region, 3-7 times of forging in an alpha-beta region, and 2 times of forming in the alpha-beta region; double-ruler or single-ruler production. Above-mentioned conventional process, total processing fire number is generally no less than 10 fire, production cycle is long, and the loss of polishing is big, and the rod tip needs to carry out crop and handle, gets rid of the inhomogeneous district of deformation tissue, even adopt double length production, every rod also need amputate 1.5 stub bars, and the yield is low, and manufacturing cost remains high.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a short-flow preparation method of a large-size bar with a fine equiaxial structure of TC4 titanium alloy, aiming at the defects of the prior art. The method adopts a process of 'hot forging blank making by a large-tonnage press machine and radial forming by a large-tonnage precision forging machine', ensures the forging permeability, fully crushes and refines crystal grains, improves the crystal grain refinement efficiency, obviously reduces the forging fire number, shortens the preparation flow, reduces the production cost and improves the yield of the TC4 titanium alloy bar.
In order to solve the technical problems, the invention adopts the technical scheme that: a short-process preparation method of a TC4 titanium alloy large-size bar with a fine equiaxial structure is characterized by comprising the following steps:
step one, adopting a large-tonnage press to perform cogging forging on a TC4 titanium alloy ingot for 2-3 times under the condition that the initial forging temperature is 1000-1150 ℃, wherein the total forging ratio of each cogging forging is not less than 6.0, the final forging temperature is not less than 900 ℃, and air cooling to obtain a primary forging stock;
step two, adopting a large-tonnage press to forge the primary forging stock obtained in the step one at the initial forging temperature of (T)β-30℃)～(TβUpsetting forging is carried out for 3-5 times at the temperature of-15 ℃, the total forging ratio of upsetting forging for each time is 5.6-10.8, the final forging temperature is not lower than 700 ℃, and the forging stock is quickly cooled to room temperature to obtain an intermediate forging stock; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, adopting a large-tonnage precision forging machine to forge the intermediate forging stock obtained in the step two at the initial forging temperature of (T)β-60℃)～(TβCarrying out radial forging for one time under the condition of minus 30 ℃ to obtain a finished radial forged bar;
step four, annealing and heat treating the finished radial forged bar obtained in the step three to obtain a TC4 titanium alloy bar; the annealing heat treatment comprises the following specific processes: keeping the temperature of the finished radial forged bar at 700-800 ℃ for 1-4 h, and then air cooling; the cross section diameter of the TC4 titanium alloy bar is 200 mm-300 mm, the length is 5000 mm-8000 mm, and the primary equiaxial alpha phase grain size rating in the TC4 titanium alloy bar is not lower than the 8-grade requirement in the GB/T6394-2017 metal average grain size determination method.
According to the invention, the TC4 titanium alloy ingot is subjected to cogging forging by adopting the large-tonnage press, the forging stock suitable for the large-tonnage press has larger weight, and the height-diameter ratio of the forging stock does not exceed 2.5 in order to avoid the occurrence of adverse phenomena such as folding, so that the cogging forging with large deformation is carried out by adopting the large-tonnage press, the original beta crystal grains in the TC4 titanium alloy ingot structure are efficiently crushed, the forging permeability is ensured, the TC4 titanium alloy ingot is not required to be cut and blanked, the polishing loss is obviously reduced, and the yield and the production efficiency of the TC4 titanium alloy bar product are favorably improved.
Then, the invention adopts a large-tonnage press to perform the forging on the primary forging stock near the top of the alpha-beta phase regionβ-30℃)～(TβNear beta forging and rapid cooling after forging are sequentially carried out at the temperature of-15 ℃ to obtain an intermediate forging stock, a primary strip beta 1 phase is effectively crushed through the near beta forging, the crushed strip alpha phase is dynamically recrystallized and spheroidized into alpha spheres, because the alpha sphere is crushed and deformed at the temperature of the top of an alpha-beta 0 phase region, the content of the alpha phase is relatively low, the further growth of the recrystallized alpha spheres in the hot processing process is inhibited, and the recrystallized alpha spheres are kept to be fine equiaxial alpha spheres, which is favorable for forming a fine crystal structure; and a large number of vacant sites are introduced into the intermediate forging stock by rapid cooling after forging, so that energy is provided for static recrystallization in the heating and heat-preserving processes of subsequent heating times, and the grain refining efficiency of a single heating time is obviously improved. In addition, because the weight of the primary forging stock is large, the temperature drop in the hot working process is slow, the deformation heat can be effectively compensated, the deformation temperature in the preparation process of the intermediate forging stock is relatively constant or slightly reduced, and the process stability is good, but the cooling speed of the intermediate forging stock is slow, the microstructure grows up in the cooling process, and the fine equiaxial structure cannot be obtained, so the growth of the microstructure in the cooling process is effectively inhibited by adopting rapid cooling after forging, and the generation of the fine equiaxial structure is further ensured. The intermediate forging stock consisting of fine equiaxed tissues, needle-shaped secondary alpha phases and beta matrixes is obtained by adopting a process of large-tonnage near beta 2 forging and rapid cooling after forging.
Finally, the invention adopts a large-tonnage precision forging machine, and the precision forging machine is arranged near the middle part of the alpha-beta phase regionβ-60℃)～(TβAt a temperature of-30 ℃ CThe method has the advantages that the method adopts a large-tonnage precision forging machine to ensure good forging penetration, improves the circumferential processing precision of the bar, and obviously improves the yield and the production efficiency; in the primary radial forging process, the acicular secondary alpha phase in the intermediate forging stock rapidly grows to form lamellar alpha phase fine sheets with large quantity and high length-width ratio, and the lamellar alpha phase fine sheets are crushed and spheroidized and then are further spheroidized and grown in the cooling process after forging, and because the thickness of the lamellar alpha phase fine sheets is relatively small, the equiaxial alpha balls obtained after crushing and spheroidizing are small in size, so that the TC4 titanium alloy bar with a fine equiaxial structure is obtained. The one-time radial forging process obviously improves the production efficiency. In addition, the diameter of the finished radial forged bar obtained after the radial forging of the first fire is obviously reduced, and the influence of the cooling rate after the forging on the size of the equiaxial alpha phase is relatively small, so that the cooling mode after the radial forging of the first fire is not limited, air cooling is usually adopted, water cooling can also be adopted for rapid cooling, the internal stress introduced by the water cooling is eliminated by subsequent annealing heat treatment, but the water cooling can cause the surface of the finished radial forged bar to form an oxide scale crust, and the scale crust needs to be removed by adopting a machining process. The large-tonnage precision forging machine is adopted for radial forging, multiple-time ruler forming is realized, and only two deformation dead zones at the end part of the intermediate forging stock after one-time radial forging are needed to be cut off, so that the end cutting amount is reduced, and the yield is improved.
The short-process preparation method of the TC4 titanium alloy thin equiaxial structure large-size bar is characterized in that in the first step, the TC4 titanium alloy ingot is a cylindrical ingot with the cross-sectional diameter of 640-820 mm. The large-size TC4 titanium alloy ingot is selected, the height-diameter ratio of the TC4 titanium alloy ingot used as a forging stock in the cogging forging process is further reduced, and the cogging forging is smoothly carried out.
The short-process preparation method of the TC4 titanium alloy thin equiaxial structure large-size bar is characterized in that in the cogging forging process in the step one, a TC4 titanium alloy ingot is repeatedly upset and drawn for 2-3 times, and the accumulated deformation of each upset and drawn is not less than 65%. The cogging forging with large deformation is selected, which is beneficial to efficiently refining the crystal grains.
The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure is characterized in that in the upsetting forging process in the step two, the primary forging stock is repeatedly upset and drawn for 3-5 times, and the accumulated deformation of each upset and drawing is 60% -100%. The deformation temperature of upsetting-drawing forging of the primary forging stock is below the phase transformation point, so that the cracking phenomenon is easily caused, the accumulated deformation amount of each upsetting and drawing is controlled, the efficient tissue refining is ensured, the process flow is shortened, the deformation cracking caused by overlarge accumulated deformation amount and the increase of the grinding loss ratio are avoided, and the preparation cost is further reduced.
The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure is characterized in that in the upsetting forging process in the step two, the primary forging stock is repeatedly upset and drawn out, and then is rapidly cooled in a water quenching mode. The optimized cooling mode improves the cooling speed, inhibits the growth of a microstructure after upsetting-drawing forging and is beneficial to obtaining a fine equiaxial structure.
The short-process preparation method of the TC4 titanium alloy thin equiaxial large-size bar is characterized in that in the first step, after each time of cogging forging, surface grinding is carried out on a TC4 titanium alloy cast ingot, and in the second step, after each time of upsetting forging, surface grinding is carried out on a primary forging stock.
The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure is characterized in that the forging ratio of the radial forging at one fire in the third step is 2.4-4.5. This preferred forging has realized the radial forging of a fire of big deflection, has improved the broken and grain refinement efficiency of tissue to improve forging efficiency, be favorable to having realized the radial forging of a fire, and the shaping precision is high.
Compared with the prior art, the invention has the following advantages:
1. the invention adopts the process of 'hot forging blank by a large-tonnage press and radial forming by a large-tonnage precision forging machine', improves the grain refining efficiency, obviously reduces the forging heat number, shortens the preparation flow, reduces the production cost, correspondingly reduces the grinding time while reducing the forging heat number, and improves the yield of the TC4 titanium alloy bar.
2. According to the invention, through near-beta forging modification and rapid cooling after forging, the primary strip-shaped alpha phase in the TC4 titanium alloy ingot is effectively crushed, so that the primary strip-shaped alpha phase is converted into fine equiaxial alpha spheres and forms a fine grain structure, the problem that the primary alpha phase grows excessively due to the fact that the air cooling rate of a large-size blank is too slow after forging is solved, a large number of vacancies are introduced, energy is provided for static recrystallization in the heating and heat preservation processes of subsequent fire, the grain refining efficiency of a single fire is obviously improved, an intermediate forging blank consisting of a fine equiaxial structure, a needle-shaped secondary alpha phase and a beta matrix is obtained, and a solid foundation is laid for the subsequent preparation of a fine equiaxial bar.
3. The invention adopts a large-tonnage press and a precision forging machine for forging, and performs multi-scale forming on the premise of ensuring the forging penetration, thereby effectively reducing the end cutting amount of the whole TC4 titanium alloy bar, and the radial forging has high circumferential precision, smaller machining amount and further improved production efficiency and yield.
4. The cross section diameter of the TC4 titanium alloy bar prepared by the method is 200-300 mm, the length of the TC4 titanium alloy bar is 5000-8000 mm, the primary equiaxial alpha phase grain size rating in the TC4 titanium alloy bar is not lower than the 8-level requirement of the GB/T6394-2017 metal average grain size determination method, and the actual use requirement is met.
The technical solution of the present invention is further described in detail by the accompanying drawings and examples.
Drawings
FIG. 1 is a microstructure diagram of a TC4 titanium alloy bar prepared in example 1 of the present invention.
FIG. 2 is a microstructure diagram of a TC4 titanium alloy bar prepared in example 2 of the present invention.
FIG. 3 is a microstructure diagram of a TC4 titanium alloy bar prepared in example 3 of the present invention.
FIG. 4 is a microstructure diagram of a TC4 titanium alloy bar prepared in comparative example 1 of the present invention.
Detailed Description
The large-tonnage presses used in examples 1 to 3 were 4500t presses, and the large-tonnage precision forging machines used were 2000t precision forging machines.
Example 1
The embodiment comprises the following steps:
step one, peeling a cylindrical 8TC4 titanium alloy cast ingot with the specification of phi 720mm multiplied by 550mm (section diameter multiplied by length) to the specification of phi 690mm multiplied by 550mm (section diameter multiplied by length), and then performing cogging forging for 2 times, wherein the initial forging temperature of the 1 st cogging forging is 1150 ℃, the final forging temperature is 930 ℃, the total forging ratio is 8.4, air cooling is performed after forging, the initial forging temperature of the 2 nd cogging forging is 1070 ℃, the final forging temperature is 930 ℃, the total forging ratio is 10.8, air cooling is performed after forging, and surface grinding treatment is performed on the TC4 titanium alloy cast ingot after each cogging forging to obtain a primary forging blank;
step two, the primary forging stock obtained in the step one is forged at the initial forging temperature of (T)βUpsetting forging is carried out for 4 times under the condition of-15 ℃, wherein the total forging ratio of each upsetting forging is 8.0, the final forging temperature is 730 ℃, the surface grinding treatment is carried out on the primary forging stock after each upsetting forging, and the intermediate forging stock with the specification of phi 350mm multiplied by 2130mm (section diameter multiplied by length) is obtained after water cooling to room temperature after forging; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, the intermediate forging stock obtained in the step two is forged at the initial forging temperature of (T)βPerforming one-time radial forging on the steel bar under the condition of minus 30 ℃, wherein the forging ratio is 2.8, and performing air cooling after forging to obtain a finished radial forged bar with the specification of phi 210mm multiplied by 5910mm (section diameter multiplied by length); the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
and step four, preserving the temperature of the finished radial forged bar obtained in the step three for 1h at the temperature of 800 ℃ (after air cooling, descaling through machining and saw cutting, and obtaining 5 TC4 titanium alloy bars with the specification of phi 200mm multiplied by 1100mm (section diameter multiplied by length).
Fig. 1 is a microstructure diagram of the TC4 titanium alloy bar prepared in this example, and as can be seen from fig. 1, the TC4 titanium alloy bar prepared in this example has a uniform structure, and the primary equiaxial α -phase grain size rating meets the requirement of level 8.5 in the GB/T6394-2017 metal average grain size determination method.
Example 2
The embodiment comprises the following steps:
step one, peeling a cylindrical TC4 titanium alloy cast ingot with the specification of phi 820mm multiplied by 950mm (section diameter multiplied by length) to phi 790mm multiplied by 550mm (section diameter multiplied by length), and then performing cogging forging for 3 times, wherein the starting forging temperature of the 1 st cogging forging is 1150 ℃, the finish forging temperature is 940 ℃, the total forging ratio is 6.0, air cooling is performed after forging, the starting forging temperature of the 2 nd cogging forging is 1100 ℃, the finish forging temperature is 920 ℃, the total forging ratio is 9.6, air cooling is performed after forging, the starting forging temperature of the 3 rd cogging forging is 1050 ℃, the finish forging temperature is 920 ℃, the total forging ratio is 10.2, air cooling is performed after forging, and surface grinding treatment is performed on the TC4 titanium alloy cast ingot after each time of cogging forging to obtain a primary forging blank;
step two, the primary forging stock obtained in the step one is forged at the initial forging temperature of (T)βUpsetting forging for 5 times at-30 ℃, wherein the total forging ratio of upsetting forging for each time is 5.6-7.2, the final forging temperature is 720-740 ℃, surface grinding treatment is carried out on the primary forging stock after upsetting forging for each time, and an intermediate forging stock with the specification of phi 410mm multiplied by 2050mm (section diameter multiplied by length) is obtained after water cooling to room temperature after forging; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, the intermediate forging stock obtained in the step two is forged at the initial forging temperature of (T)βRadial forging is carried out for one time under the condition of minus 60 ℃, the forging ratio is 2.5, air cooling is carried out after forging, and a finished radial forged bar with the specification of phi 310mm multiplied by 5200mm (section diameter multiplied by length) is obtained; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
and step four, preserving the temperature of the finished radial forged bar obtained in the step three for 4 hours at 700 ℃, then air-cooling, mechanically processing to remove oxide skin, and sawing to obtain 4 TC4 titanium alloy bars with the specification of phi 300mm multiplied by 1150mm (section diameter multiplied by length).
Fig. 2 is a microstructure diagram of the TC4 titanium alloy bar prepared in this example, and as can be seen from fig. 2, the TC4 titanium alloy bar prepared in this example has a uniform structure, and the primary equiaxial α -phase grain size rating meets the requirement of level 8 in the GB/T6394-2017 metal average grain size determination method.
Example 3
The embodiment comprises the following steps:
step one, peeling a cylindrical TC4 titanium alloy cast ingot with the specification of phi 640mm multiplied by 550mm (section diameter multiplied by length) to phi 609mm multiplied by 550mm (section diameter multiplied by length), and then performing cogging forging for 3 times, wherein the initial forging temperature of the 1 st cogging forging is 1150 ℃, the finish forging temperature is 910 ℃, the total forging ratio is 8.4, air cooling is performed after forging, the initial forging temperature of the 2 nd cogging forging and the 3 rd cogging forging is 1070 ℃, the finish forging temperature is 920 ℃, the total forging ratio is 10.2, air cooling is performed after forging, and surface grinding treatment is performed on the TC4 titanium alloy cast ingot after each time of cogging forging to obtain a primary forging blank;
step two, the primary forging stock obtained in the step one is forged at the initial forging temperature of (T)βUpsetting forging for 3 times at the temperature of-25 ℃, wherein the total forging ratio of each upsetting forging for 3 times is 7.2, the final forging temperature is 710-740 ℃, the surface grinding treatment is carried out on the primary forging stock after each upsetting forging for 3 times, and the intermediate forging stock with the specification of phi 510mm multiplied by 1690mm (section diameter multiplied by length) is obtained after water cooling to the room temperature after forging; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, the intermediate forging stock obtained in the step two is forged at the initial forging temperature of (T)βPerforming one-time radial forging on the steel bar under the condition of minus 50 ℃, wherein the forging ratio is 4.5, and performing air cooling after forging to obtain a finished radial forged bar with the specification of phi 240mm multiplied by 7630mm (section diameter multiplied by length); the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
and step four, preserving the temperature of the finished radial forged bar obtained in the step three for 2 hours at the temperature of 750 ℃, then air-cooling, removing oxide skin through machining, and sawing to obtain 5 TC4 titanium alloy bars with the specification of phi 230mm multiplied by 1400mm (section diameter multiplied by length).
Fig. 3 is a microstructure diagram of the TC4 titanium alloy bar prepared in this embodiment, and as can be seen from fig. 3, the TC4 titanium alloy bar prepared in this embodiment has a uniform structure, and the primary equiaxial α -phase grain size rating meets the requirement of level 9 in the GB/T6394-2017 metal average grain size determination method.
Comparative example 1
This comparative example comprises the following steps:
step one, peeling cylindrical TC4 titanium alloy ingots with the specification of phi 720mm multiplied by 640mm (section diameter multiplied by length) to the specification of phi 690mm multiplied by 640mm (section diameter multiplied by length), and then performing cogging forging for 4 times, wherein the initial forging temperature of the 1 st cogging forging and the 2 nd cogging forging is 1150 ℃, the final forging temperature is 940 ℃, the total forging ratio is 8.4, air cooling is performed after forging, the initial forging temperature of the 3 rd cogging forging and the 4 th cogging forging is 1050 ℃, the final forging temperature is 910 ℃, the total forging ratio is 8.4, air cooling is performed after forging, and surface grinding treatment is performed on TC4 titanium alloy ingots after each time of cogging forging to obtain primary forging blanks;
step two, the primary forging stock obtained in the step one is forged at the initial forging temperature of (T)βUpsetting forging for 4 times at-30 ℃, wherein the total forging ratio of each upsetting forging for 4 times is 6.0, the final forging temperature is 710 ℃, the surface grinding treatment is carried out on the primary forging stock after each upsetting forging for 4 times, and the intermediate forging stock with the specification of phi 325mm multiplied by 1450mm (section diameter multiplied by length) is obtained after water cooling to room temperature after forging; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, the intermediate forging stock obtained in the step two is forged at the initial forging temperature of (T)βCarrying out radial forging twice under the condition of minus 30 ℃, wherein the forging ratio is 2.4, and carrying out air cooling after forging to obtain a finished radial forged bar with the specification of phi 220mm multiplied by 3160mm (section diameter multiplied by length); the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
and step four, preserving the temperature of the finished radial forged bar obtained in the step three for 2 hours at the temperature of 750 ℃, then air-cooling, removing oxide skin through machining, and sawing to obtain 2 TC4 titanium alloy bars with the specification of phi 200mm multiplied by 1100mm (section diameter multiplied by length).
Fig. 4 is a microstructure diagram of the TC4 titanium alloy bar prepared by the comparative example, and as can be seen from fig. 4, the TC4 titanium alloy bar prepared by the present example has a uniform structure, and the primary equiaxial α -phase grain size rating meets the requirement of level 9 in the GB/T6394-2017 metal average grain size determination method.
The room temperature mechanical properties of the TC4 titanium alloy bars prepared in examples 1 to 3 of the present invention and comparative example 1 were measured, and the results are shown in table 1.
TABLE 1 mechanical properties at room temperature of TC4 titanium alloy bars prepared in examples 1-3 and comparative example 1
Figure BDA0002443452930000101
As can be seen from table 1, the room temperature mechanical properties of the TC4 titanium alloy bars prepared in examples 1 to 3 and comparative example 1 of the present invention all satisfy the requirements of the technical specification, and the room temperature mechanical properties of the TC4 titanium alloy bars prepared in examples 1 to 3 are slightly better than that of comparative example 1. Meanwhile, comparing the example 1 with the comparative example 1 adopting the existing preparation process, it can be seen that the total forging number of times of the comparative example 1 is 10, the radial turning amount of the finished product TC4 titanium alloy bar is about 17%, the end cutting amount is about 11.4% of the total length, while the total forging number of times of the example 1 is 7, the radial turning amount of the finished product TC4 titanium alloy bar is about 9.3%, and the end cutting amount is about 5% of the total length, and compared with the comparative example 1, the machining yield of the TC4 titanium alloy bar prepared in the example 1 after turning and end sawing is improved by about 14.1% compared with the comparative example 1, the production cost is reduced by about 30 yuan/kg, the forging number of times is reduced by 3 times, the production cost is reduced by about 12 yuan/kg, the room temperature mechanical properties of the TC4 titanium alloy bar prepared in the comparative example 1 and the example 1 both meet the technical index requirements, and the initial isometric alpha phase grain size rating is not lower than the 8-grade requirement in the GB/T6394-2017 metal average grain size determination method, the preparation method shortens the production period of the TC4 titanium alloy thin equiaxial structure large-size bar, obviously reduces the production and realizes the short-flow preparation.
The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way. Any simple modification, change and equivalent changes of the above embodiments according to the technical essence of the invention are still within the protection scope of the technical solution of the invention.

Claims (7)

1. A short-process preparation method of a TC4 titanium alloy large-size bar with a fine equiaxial structure is characterized by comprising the following steps:
step one, adopting a large-tonnage press to perform cogging forging on a TC4 titanium alloy ingot for 2-3 times under the condition that the initial forging temperature is 1000-1150 ℃, wherein the total forging ratio of each cogging forging is not less than 6.0, the final forging temperature is not less than 900 ℃, and air cooling to obtain a primary forging stock;
step two, adopting a large-tonnage press to forge the primary forging stock obtained in the step one at the initial forging temperature of (T)β-30℃)～(TβUpsetting forging is carried out for 3-5 times at the temperature of-15 ℃, the total forging ratio of upsetting forging for each time is 5.6-10.8, the final forging temperature is not lower than 700 ℃, and the forging stock is quickly cooled to room temperature to obtain an intermediate forging stock; the T isβBeta phase transition temperature, T, of TC4 titanium alloyβThe unit of (A) is;
step three, adopting a large-tonnage precision forging machine to forge the intermediate forging stock obtained in the step two at the initial forging temperature of (T)β-60℃)～(TβCarrying out radial forging for one time under the condition of minus 30 ℃ to obtain a finished radial forged bar;
step four, annealing and heat treating the finished radial forged bar obtained in the step three to obtain a TC4 titanium alloy bar; the annealing heat treatment comprises the following specific processes: keeping the temperature of the finished radial forged bar at 700-800 ℃ for 1-4 h, and then air cooling; the cross section diameter of the TC4 titanium alloy bar is 200 mm-300 mm, the length is 5000 mm-8000 mm, and the primary equiaxial alpha phase grain size rating in the TC4 titanium alloy bar is not lower than the 8-grade requirement in the GB/T6394-2017 metal average grain size determination method.
2. The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure according to claim 1, wherein in the first step, the TC4 titanium alloy ingot is a cylindrical ingot with the cross-sectional diameter of 640-820 mm.
3. The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure according to claim 1, wherein in the cogging forging process in the step one, the TC4 titanium alloy ingot is repeatedly upset and drawn for 2-3 times, and the accumulated deformation of each upset and drawn is not less than 65%.
4. The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure according to claim 1, wherein in the upsetting forging process in the step two, the primary forging stock is repeatedly upset and drawn for 3-5 times, and the accumulated deformation of each upset and drawing is 60-100%.
5. The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure according to claim 1, wherein in the upsetting forging process in the step two, the primary forging stock is repeatedly upset and drawn out, and then is rapidly cooled by means of water quenching.
6. The method for preparing the large-size bar with the TC4 titanium alloy fine equiaxial structure in the short process according to claim 1, wherein the surface grinding treatment is carried out on the TC4 titanium alloy ingot after each time of the cogging forging in the step one, and the surface grinding treatment is carried out on the primary forging stock after each time of the upsetting forging in the step two.
7. The short-process preparation method of the TC4 titanium alloy large-size bar with the fine equiaxial structure according to claim 1, wherein the forging ratio of the first-fire radial forging in the third step is 2.4-4.5.
CN202010272116.6A 2020-04-09 2020-04-09 Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure Active CN111286686B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010272116.6A CN111286686B (en) 2020-04-09 2020-04-09 Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010272116.6A CN111286686B (en) 2020-04-09 2020-04-09 Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure

Publications (2)

Publication Number Publication Date
CN111286686A CN111286686A (en) 2020-06-16
CN111286686B true CN111286686B (en) 2021-09-10

Family

ID=71018561

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010272116.6A Active CN111286686B (en) 2020-04-09 2020-04-09 Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure

Country Status (1)

Country Link
CN (1) CN111286686B (en)

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112371886B (en) * 2020-09-12 2023-01-10 武汉第二船舶设计研究所(中国船舶重工集团公司第七一九研究所) Forging method of large-size titanium alloy bar blank for gas cylinder
CN112355214B (en) * 2020-10-20 2022-06-10 湖南金天钛业科技有限公司 Preparation method of large-size forging for heavy rocket binding support
CN112548010B (en) * 2020-11-05 2024-04-09 宝钛集团有限公司 Preparation method of titanium alloy elliptical ring material
CN112719199B (en) * 2020-12-14 2023-05-23 江苏宇钛新材料有限公司 Preparation method of large-caliber titanium alloy thick-wall pipe
CN112795812A (en) * 2020-12-30 2021-05-14 西安西工大超晶科技发展有限责任公司 TC4 titanium alloy bar and preparation method thereof
CN113182476B (en) * 2021-04-28 2023-10-13 西部钛业有限责任公司 Preparation method of high-strength TC11 titanium alloy forging
CN113305261B (en) * 2021-06-10 2023-02-28 西部超导材料科技股份有限公司 Preparation method of TC4 titanium alloy thin-wall high-cylinder ring or pipe forging
CN114273575B (en) * 2021-06-11 2023-04-18 宁夏中色金航钛业有限公司 Large-deformation short-flow forging method
CN114346137B (en) * 2021-12-06 2023-10-13 中国科学院金属研究所 Hot working preparation method of large-size titanium alloy bar with uniform ribbon-shaped structure
CN114457259A (en) * 2022-01-23 2022-05-10 西部超导材料科技股份有限公司 Fine-grain TC4 titanium alloy bar and preparation method thereof
CN114850368B (en) * 2022-06-14 2023-04-11 西部钛业有限责任公司 Preparation method of ultra-large TC4 titanium alloy bar with high flaw detection requirement
CN115747689B (en) * 2022-11-29 2023-09-29 湖南湘投金天钛业科技股份有限公司 High-plasticity forging method for Ti-1350 ultrahigh-strength titanium alloy large-size bar

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102418060A (en) * 2011-12-12 2012-04-18 西部钛业有限责任公司 Processing method for TC4 titanium alloy large-sized bar
CN102943228A (en) * 2012-12-14 2013-02-27 西北有色金属研究院 Machining method for improving obdurability of two-phase titanium alloy large-size bar
CN103397289A (en) * 2013-08-11 2013-11-20 西北有色金属研究院 Preparation method of TC4ELI titanium alloy bar
CN104841830A (en) * 2015-05-21 2015-08-19 西部超导材料科技股份有限公司 Method for manufacturing TC4-DT titanium alloy large-size forged blanks
CN110508731A (en) * 2019-08-29 2019-11-29 陕西天成航空材料有限公司 A kind of forging method improving TC4 titanium alloy large-scale forging structural homogenity

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2717717B1 (en) * 1994-03-24 1996-05-15 Cezus Co Europ Zirconium Method for manufacturing a tubular zircaloy 2 blank internally plated with zirconium and suitable for ultrasonic control of the zirconium thickness.
US6136105A (en) * 1998-06-12 2000-10-24 Lockheed Martin Corporation Process for imparting high strength, ductility, and toughness to tungsten heavy alloy (WHA) materials
CN102492907A (en) * 2011-12-07 2012-06-13 西部钛业有限责任公司 Preparation method of TA7ELI titanium alloy cake material
CN103436831B (en) * 2013-08-16 2015-02-18 宝鸡市永盛泰钛业有限公司 Preparation method for titanium alloy bar for surgical implants
CN103510030B (en) * 2013-09-23 2015-08-05 西北有色金属研究院 A kind of preparation method of TC21 titanium alloy large size bar
CN104762576B (en) * 2015-04-24 2016-10-12 西北有色金属研究院 The preparation method of TC18 titanium alloy the whole network basket tissue medium format overlength bar
CN106734318B (en) * 2016-12-09 2018-10-16 西部钛业有限责任公司 A kind of Ti2The processing method of AlNb alloy wide sheets
CN106925612B (en) * 2017-03-24 2018-12-25 西部钛业有限责任公司 A kind of processing method of high dimensional accuracy TA15 titanium alloy wide medium-thick plate
JP7223121B2 (en) * 2018-08-31 2023-02-15 ザ・ボーイング・カンパニー High-strength fastener material by forged titanium alloy and its manufacturing method

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102418060A (en) * 2011-12-12 2012-04-18 西部钛业有限责任公司 Processing method for TC4 titanium alloy large-sized bar
CN102943228A (en) * 2012-12-14 2013-02-27 西北有色金属研究院 Machining method for improving obdurability of two-phase titanium alloy large-size bar
CN103397289A (en) * 2013-08-11 2013-11-20 西北有色金属研究院 Preparation method of TC4ELI titanium alloy bar
CN104841830A (en) * 2015-05-21 2015-08-19 西部超导材料科技股份有限公司 Method for manufacturing TC4-DT titanium alloy large-size forged blanks
CN110508731A (en) * 2019-08-29 2019-11-29 陕西天成航空材料有限公司 A kind of forging method improving TC4 titanium alloy large-scale forging structural homogenity

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
采用Φ600mm铸锭锻造的大规格TC4棒材的组织和性能;朱宝辉等;《热加工工艺》;20140731;第43卷(第13期);第109-112、117页 *

Also Published As

Publication number Publication date
CN111286686A (en) 2020-06-16

Similar Documents

Publication Publication Date Title
CN111286686B (en) Short-process preparation method of TC4 titanium alloy large-size bar with fine equiaxial structure
CN111763850B (en) Processing method of fine-grain superplasticity TA15 titanium alloy medium-thick plate
CN103361586B (en) Processing method for raising strength and toughness of TC4-DT titanium alloy sheet materials
CN110205571B (en) Preparation method of TC18 titanium alloy large-size bar
CN108890218B (en) Manufacturing process of high-strength heat-resistant aluminum alloy forging
CN111036705B (en) Large-caliber titanium alloy seamless pipe and preparation method thereof
CN110592508B (en) Low-cost and high-performance titanium alloy short-process forging process
CN112981174B (en) Preparation method of high-strength high-plasticity titanium alloy wire
CN112338119B (en) Method for forging near-alpha type high-temperature titanium alloy large-size bar
CN111560547A (en) Preparation method of 5182-O-state aluminum alloy plate for automobile
CN101323939B (en) Heat working process for improving titanium alloy fracture toughness property and anti-fatigue strength
CN113649503A (en) High-strength beta forging titanium alloy forging structure control method for aircraft engine
CN114367611A (en) Magnesium alloy revolving body structural part and preparation process thereof
CN113564397B (en) Short-process preparation method of medium-strength high-toughness titanium alloy medium-thickness plate
CN113182476B (en) Preparation method of high-strength TC11 titanium alloy forging
CN110205572B (en) Preparation method of two-phase Ti-Al-Zr-Mo-V titanium alloy forged rod
CN114653751A (en) Preparation method of duplex stainless steel cold-rolled ribbed steel bar
CN110976512A (en) Cold rolling method for TC4 titanium alloy wire
CN115747689A (en) High-plasticity forging method for Ti-1350 ultrahigh-strength titanium alloy large-size bar
CN114871277A (en) Efficient low-cost preparation method of industrial pure titanium rod blank for ultra-long fine-grain cross-piercing
CN113118349B (en) Preparation method of Ti6242 titanium alloy large-thickness cake blank
CN112646998A (en) Aluminum alloy for aircraft wall plate and preparation method of plate
CN114433764B (en) Preparation method of TA22 titanium alloy forged piece with high plastic toughness
CN115740306B (en) Preparation method of Ti6Al4V titanium alloy bar
CN114799002B (en) Forging method of ultra-large high-temperature alloy cake blank

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant