Upsetting blank making method for titanium alloy with large height-diameter ratio

Abstract

The invention relates to the technical field of bar upsetting rough machining, in particular to a large height-diameter ratio titanium alloy upsetting blank manufacturing method. Comprising the following steps that S1, the upper end face and the lower end face of a bar are machined, so that the upper end face and the lower end face of the bar are perpendicular to the axis of the bar; s2, first heating number upsetting is carried out, and a first rod-shaped rough blank is obtained; s3, second heating number upsetting is carried out, and a second rod-shaped rough blank is obtained; s4, third heating number upsetting is conducted, and a third rod-shaped rough blank is obtained; s5, upsetting for the fourth heating number to obtain a cake-shaped rough blank; according to the method, the middle of the bar is deformed into the first bar-shaped rough blank through the first heating number of upsetting, the head of the first bar-shaped rough blank is deformed into the second bar-shaped rough blank through the second heating number of upsetting, and the tail of the second bar-shaped rough blank is deformed into the third bar-shaped rough blank through the third heating number of upsetting; and the third rod-shaped rough blank is upset into a cake-shaped rough blank through fourth heating number upsetting, different molds are designed for each heating number, and the situation that a bar with the large height-diameter ratio is folded, inclined and bent in an unstable mode in the upsetting process is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of bar roughing processing, in particular to a method for roughing and forming a titanium alloy blank with a large aspect ratio. Background Art

[0002] With the development of aerospace engines, the development of new engines has put forward higher requirements for large-sized, high-performance titanium alloy disc forgings. The increase in size has greatly increased the weight of titanium alloy disc forgings for engines, which leads to the need for larger bars or round blanks during forging. However, in actual production, even if large-diameter bars are used, they need to be upset into larger-sized pancake blanks. The height-to-diameter ratio during upset often exceeds 3:1. Such bars with a large height-to-diameter ratio (height-to-diameter ratio exceeding 3:1) are prone to folding, tilting and unstable bending during the upset process. If the upset and straightening process is adopted, the operation is difficult and difficult to achieve. At the same time, due to the limitations of technical conditions, the uniformity and performance of large-diameter titanium alloy bars are difficult to meet the standard requirements, and there are often many metallurgical defects. When using small-diameter bars for upset billeting, the height-to-diameter ratio will be doubled (the height-to-diameter ratio can reach 8:1), which is difficult to meet the demand for pancake blanks in die forging. Therefore, how to efficiently and smoothly upset and forge bars with a large aspect ratio is a hot topic and urgent need in the current forging industry. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for upsetting a titanium alloy with a large aspect ratio, which is used to prevent the bar with a large aspect ratio from folding, tilting and unstable bending during the upsetting process.

[0004] The technical solution adopted by the present invention to solve the technical problem is a method for upsetting a titanium alloy with a large aspect ratio, comprising the following steps:

[0005] S1: Machining the upper and lower end surfaces of the bar material so that the upper and lower end surfaces of the bar material are perpendicular to the axis of the bar material;

[0006] S2: First fire roughing, the bar is placed in a heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.8~1.2min / mm; before the bar is taken out of the furnace, two first dies are respectively installed on the lower die seat and the upper die seat of the hydraulic fast forging machine, and the upper surface of the first die is provided with a first countersunk hole, and the diameter of the bottom of the first countersunk hole is smaller than the diameter at the opening and larger than the diameter of the bar; the first countersunk holes of the two first dies installed on the lower die seat and the upper die seat are opposite, and the heated bar is placed in the first countersunk hole, so that the bar is coaxial with the first countersunk hole, and the two ends of the bar are respectively in contact with the bottom surfaces of the two first countersunk holes, and the hydraulic fast forging machine drives the upper die seat to move downward, the moving speed is 4~10mm / s, and the moving distance is 25%~30% of the length of the bar, to obtain the first rod-shaped blank;

[0007] S3: The second roughening is performed by heating the first rod-shaped blank in a heating furnace at a temperature of Tβ-50 to Tβ-30°C and a heating coefficient of 0.4 to 1.2 min / mm. Before the first rod-shaped blank is taken out of the furnace, the first die is installed on the lower die base of the hydraulic fast forging machine, and the third die is installed on the upper die base of the hydraulic fast forging machine. A third countersunk hole is provided on the lower surface of the third die. The diameter of the bottom of the third countersunk hole is smaller than the diameter of the opening, and the diameter of the opening of the third countersunk hole is larger than the diameter of the opening of the first countersunk hole. The diameter of the bottom of the third countersunk hole is greater than the diameter of the bottom of the first countersunk hole; the first countersunk hole and the third countersunk hole are opposite to each other, the heated first rod-shaped blank is placed in the first countersunk hole and the third countersunk hole, the first rod-shaped blank is coaxial with the first countersunk hole and the third countersunk hole, and the two ends of the first rod-shaped blank are respectively abutted against the bottom surfaces of the first countersunk hole and the third countersunk hole, and the hydraulic fast forging machine drives the third die to move downward at a moving speed of 4 to 10 mm / s, and the moving distance is 22% to 27% of the length of the first rod-shaped blank, to obtain a second rod-shaped blank;

[0008] S4: The third fire roughing, the second rod-shaped blank is put into the heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, the heating coefficient is 0.4~1.2min / mm; before the second rod-shaped blank is taken out of the furnace, the fourth die is installed on the lower die base of the hydraulic fast forging machine, the third die is installed on the upper die base of the hydraulic fast forging machine, the upper surface of the fourth die is provided with a fourth countersink, the diameter of the bottom of the fourth countersink is smaller than the diameter of the opening, the diameter of the opening of the fourth countersink is larger than the diameter of the opening of the third countersink, and the diameter of the bottom of the fourth countersink is larger than The diameter of the bottom of the third countersunk hole; the fourth countersunk hole is opposite to the third countersunk hole, and the two ends of the heated second rod-shaped blank are respectively placed in the fourth countersunk hole and the third countersunk hole, and abut against the bottom surfaces of the fourth countersunk hole and the third countersunk hole, wherein the end placed in the fourth countersunk hole is the end formed in the third countersunk hole in step S3, the second rod-shaped blank is coaxial with the fourth countersunk hole and the third countersunk hole, and the hydraulic fast forging machine drives the third die to move downward at a moving speed of 5 to 8 mm / s, and the moving distance is 43% to 48% of the length of the second rod-shaped blank, to obtain a third rod-shaped blank;

[0009] S5: The third rod-shaped blank is put into a heating furnace for heating at a temperature of Tβ-50 to Tβ-30°C and a heating coefficient of 0.4 to 1.2 min / mm. Before the third rod-shaped blank is taken out of the furnace, the lower flat anvil is installed on the lower die base of the hydraulic forging machine, and the upper flat anvil is installed on the upper die base of the hydraulic forging machine. The heated third rod-shaped blank is placed on the lower flat anvil, and the bottom surface of the upper flat anvil is in contact with the upper surface of the third rod-shaped blank. The hydraulic forging machine drives the upper flat anvil to move downward at a speed of 5 to 8 mm / s, and the moving distance is 45% to 55% of the length of the third rod-shaped blank to obtain a pancake-shaped blank.

[0010] Furthermore, the first mold, the third mold, the fourth mold, the upper anvil and the lower anvil are all placed in a furnace and preheated to ≥200° C. before use.

[0011] Furthermore, the time from when the bar material is taken out of the furnace to when the positioning is completed, the time from when the first rod-shaped blank is taken out of the furnace to when the positioning is completed, the time from when the second rod-shaped blank is taken out of the furnace to when the positioning is completed, and the time from when the third rod-shaped blank is taken out of the furnace to when the positioning is completed are all no more than 200 seconds.

[0012] Further, in step S2, after the first die is installed on the lower die base of the hydraulic fast forging machine, a lubricating fiber cloth is laid at the opening of the first countersunk hole. In step S3, a lubricating fiber cloth is laid at the opening of the first countersunk hole. In step S4, a lubricating fiber cloth is laid at the opening of the fourth countersunk hole. In step S5, thermal insulation cotton is laid on the upper and lower end surfaces of the third rod-shaped blank with a thickness of 15 mm.

[0013] Furthermore, the hydraulic fast forging press is a 45MN hydraulic fast forging press.

[0014] Furthermore, the heating furnace adopts a large industrial resistance furnace, the electric furnace meets or exceeds the Class III standard of the GJB standard, and the accuracy of the electric furnace is ±10°C.

[0015] The beneficial effects of the present invention are as follows: the middle part of the rod is transformed into a first rod-shaped blank through the first roughening fire, the head of the first rod-shaped blank is transformed into a second rod-shaped blank through the second roughening fire, the tail of the second rod-shaped blank is transformed into a third rod-shaped blank through the third roughening fire, and the third rod-shaped blank is roughened into a pancake-shaped blank through the fourth roughening fire. Different molds are designed for each roughening fire to avoid folding, tilting and unstable bending of rods with a large aspect ratio during the roughening process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the first-fire roughing of the present invention;

[0017] Figure 2 is a schematic diagram of the first mold and the third mold;

[0018] Figure 3 is a schematic diagram of the third mold and the fourth mold;

[0019] Figure 4 is a schematic diagram of an upper flat anvil and a lower flat anvil;

[0020] Figure 5 It is a process diagram of bar deformation.

[0021] Figure numerals: 1-first mold; 101-first countersunk hole; 2-third mold; 201-third countersunk hole; 3-fourth mold; 301-fourth countersunk hole; 4-lower flat anvil; 401-thermal insulation cotton; 5-upper flat anvil; 6-lubricating fiber cloth. DETAILED DESCRIPTION

[0022] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] The present invention provides a method for upsetting and making a billet of a titanium alloy with a large aspect ratio, comprising the following steps:

[0024] S1: Machining the upper and lower end faces of the bar material so that they are perpendicular to the axis of the bar material; machining the end faces of the bar material to ensure the flatness of the end faces of the bar material, the end faces are parallel and perpendicular to the axis of the bar material, and the risk of bending and skewing during the bar upsetting process is reduced.

[0025] S2: First fire roughing, see Figure 1 , the bar is placed in a heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.8~1.2min / mm; before the bar is taken out of the furnace, two first dies 1 are respectively installed on the lower die seat and the upper die seat of the hydraulic fast forging machine, and the upper surface of the first die 1 is provided with a first countersunk hole 101, and the diameter of the bottom of the first countersunk hole 101 is smaller than the diameter at the opening and larger than the diameter of the bar; the first countersunk holes 101 of the two first dies 1 installed on the lower die seat and the upper die seat are opposite, and the heated bar is placed in the first countersunk hole 101, so that the bar is coaxial with the first countersunk hole 101, and the two ends of the bar are respectively in contact with the bottom surfaces of the two first countersunk holes 101, and the hydraulic fast forging machine drives the upper die seat to move downward, the moving speed is 4~10mm / s, and the moving distance is 25%~30% of the length of the bar, to obtain the first rod-shaped blank;

[0026] The first fire roughening adopts a heating temperature of Tβ-50~Tβ-30℃, so that the titanium alloy is in the two-phase region. The material has good plasticity during forging, the deformation resistance is reduced, the roughening tonnage is greatly reduced, and the atomic diffusion and grain boundary migration capabilities of the material are improved, making it easier to cause dynamic recovery and recrystallization. A heating coefficient of 0.8~1.2min / mm is used to ensure that all parts of the bar blank are fully heated, and the heating time is the heating coefficient*the maximum diameter of the forging. When the height-to-diameter ratio of the bar is greater than 3, the bar is very likely to produce a double drum shape during the roughening process. The deformation of the bar mainly occurs at the head and tail, and the waist deformation is small. Continuous roughening is easy to cause bending and folding, and forging is difficult. By setting a first countersunk hole 101 on the first die 1, the diameter of the bottom of the first countersunk hole 101 is smaller than the diameter of the opening and larger than the diameter of the bar, limiting the space for deformation of the head and tail materials of the bar, forcing the middle of the bar to deform, and avoiding the appearance of double drums. When a bar with a large aspect ratio is upset, the greater the deformation speed, the greater the risk of bending during forging. Therefore, a forging speed of 4 to 10 mm / s is used to avoid bending and deformation of the bar during upsetting forging. The moving distance is 25% to 30% of the bar length, that is, the deformation of the bar in the axial direction is 25% to 30%. It should be noted here that there is a relationship between the depth of the first countersunk hole 101 and the length of the bar. For example, if the deformation of the bar is 25%, the depth of the first countersunk hole 101 shall not exceed 37.5% of the length of the bar. If the deformation of the bar is 30%, the depth of the first countersunk hole 101 shall not exceed 35% of the length of the bar.

[0027] S3: Second fire roughing, see Figure 2 , the first rod-shaped blank is placed in a heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.4~1.2min / mm; before the first rod-shaped blank is taken out of the furnace, the first die 1 is installed on the lower die base of the hydraulic fast forging machine, and the third die 2 is installed on the upper die base of the hydraulic fast forging machine. The lower surface of the third die 2 is provided with a third countersunk hole 201, and the diameter of the bottom of the third countersunk hole 201 is smaller than the diameter of the opening, and the diameter of the opening of the third countersunk hole 201 is larger than the diameter of the opening of the first countersunk hole 101, and the diameter of the bottom of the third countersunk hole 201 is smaller than the diameter of the opening of the first countersunk hole 101. The diameter is larger than the diameter of the bottom of the first countersunk hole 101; the first countersunk hole 101 and the third countersunk hole 201 are opposite to each other, the first rod-shaped blank is heated and placed in the first countersunk hole 101 and the third countersunk hole 201, the first rod-shaped blank is coaxial with the first countersunk hole 101 and the third countersunk hole 201, and the two ends of the first rod-shaped blank are respectively abutted against the bottom surfaces of the first countersunk hole 101 and the third countersunk hole 201, and the hydraulic fast forging machine drives the third die 2 to move downward at a speed of 4 to 10 mm / s, and the moving distance is 22% to 27% of the length of the first rod-shaped blank, to obtain a second rod-shaped blank;

[0028] The main purpose of the second upsetting is to upsetting the head of the first rod-shaped blank. Since the diameter of the first rod-shaped blank is increased by the first upsetting, the heating coefficient of the second upsetting can be smaller than that of the first upsetting, so that all parts of the first rod-shaped blank are fully heated. The first die 1 is installed on the lower die seat of the hydraulic forging machine. Since the first die 1 is used in the first upsetting, the bar has been deformed in the first die 1. Therefore, in the second upsetting, the first die 1 can limit the deformation space of the tail material of the bar. The diameter of the opening of the third countersunk hole 201 is greater than the diameter of the opening of the first countersunk hole 101, and the diameter of the bottom of the third countersunk hole 201 is greater than the diameter of the bottom of the first countersunk hole 101. When the hydraulic forging machine drives the third die 2 to move downward, the part of the first rod-shaped blank located in the third countersunk hole 201 is upset, and the moving speed is 4 to 10 mm / s. The forging speed of 4 to 10 mm / s is used to avoid bending and deformation of the bar during the upsetting forging process.

[0029] S4: The third fire, see Figure 3 , the second rod-shaped blank is placed in a heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.4~1.2min / mm; before the second rod-shaped blank is taken out of the furnace, the fourth die 3 is installed on the lower die base of the hydraulic fast forging machine, and the third die 2 is installed on the upper die base of the hydraulic fast forging machine. The upper surface of the fourth die 3 is provided with a fourth countersunk hole 301, and the diameter of the bottom of the fourth countersunk hole 301 is smaller than the diameter at the opening, and the diameter of the opening of the fourth countersunk hole 301 is larger than the diameter of the opening of the third countersunk hole 201, and the diameter of the bottom of the fourth countersunk hole 301 is larger than the diameter of the bottom of the third countersunk hole 201 The fourth countersunk hole 301 is opposite to the third countersunk hole 201, and the two ends of the heated second rod-shaped blank are respectively placed in the fourth countersunk hole 301 and the third countersunk hole 201, and abut against the bottom surfaces of the fourth countersunk hole 301 and the third countersunk hole 201, wherein the end placed in the fourth countersunk hole 301 is the end formed in the third countersunk hole 201 in step S3, and the second rod-shaped blank is coaxial with the fourth countersunk hole 301 and the third countersunk hole 201, and the hydraulic fast forging machine drives the third die 2 to move downward at a moving speed of 5 to 8 mm / s, and the moving distance is 43% to 48% of the length of the second rod-shaped blank, to obtain a third rod-shaped blank;

[0030] The main purpose of the third fire roughing is to roughen the tail of the second rod-shaped blank. The fourth die 3 is installed on the lower die seat of the hydraulic fast forging machine. The upper surface of the fourth die 3 is provided with a fourth countersunk hole 301. The diameter of the bottom of the fourth countersunk hole 301 is smaller than the diameter of the opening. The diameter of the opening of the fourth countersunk hole 301 is larger than the diameter of the opening of the third countersunk hole 201. The diameter of the bottom of the fourth countersunk hole 301 is larger than the diameter of the bottom of the third countersunk hole 201. The fourth countersunk hole 301 is opposite to the third countersunk hole 201. Due to the second fire After roughening, the length of the tail of the second rod-shaped blank is greater than the length of the head, so the depth of the fourth countersunk hole 301 needs to be greater than the depth of the third countersunk hole 201, and when the head of the second rod-shaped blank is placed in the fourth countersunk hole 301, it will not interfere with the hole wall of the fourth countersunk hole 301. The third die 2 is installed on the upper die base of the hydraulic fast forging machine, and the fourth die 3 can limit the space for deformation of the material at the head of the rod blank, forcing the tail of the second rod-shaped blank to deform, increasing the material aggregation of the tail section of the rod blank, and making the diameter of the tail of the second rod-shaped blank equivalent to the diameter of the head.

[0031] S5: The fourth fire, see Figure 4 , put the third rod-shaped blank into the heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.4~1.2min / mm; before the third rod-shaped blank is taken out of the furnace, the lower flat anvil 4 is installed on the lower die base of the hydraulic fast forging machine, and the upper flat anvil 5 is installed on the upper die base of the hydraulic fast forging machine. The heated third rod-shaped blank is placed on the lower flat anvil 4, and the bottom surface of the upper flat anvil 5 is in contact with the upper surface of the third rod-shaped blank. The hydraulic fast forging machine drives the upper flat anvil 5 to move downward at a speed of 5~8mm / s, and the moving distance is 45%~55% of the length of the third rod-shaped blank to obtain a pancake-shaped blank; after the first fire roughening, the second fire roughening and the third fire roughening, the height-to-diameter ratio of the third rod-shaped blank is less than 3, and the flat anvil can be used for roughening.

[0032] Further, the first die 1, the third die 2, the fourth die 3, the upper anvil 5 and the lower anvil 4 are all placed in a furnace and preheated to ≥ 200° C. The first die 1, the third die 2, the fourth die 3, the upper anvil 5 and the lower anvil 4 are preheated to reduce the rate of decrease of the bar temperature during the forging process.

[0033] In order to ensure the temperature of the bar during forging, further, the time from the bar being taken out of the furnace to the completion of positioning, the time from the first rod-shaped blank being taken out of the furnace to the completion of positioning, the time from the second rod-shaped blank being taken out of the furnace to the completion of positioning, and the time from the third rod-shaped blank being taken out of the furnace to the completion of positioning shall not exceed 200S.

[0034] In order to facilitate the removal of the forging after forging is completed, see Figure 2 , Figure 3 and Figure 4In step S2, after the first die 1 is installed on the lower die base of the hydraulic fast forging machine, a lubricating fiber cloth 6 is laid at the opening of the first countersunk hole 101. In step S3, a lubricating fiber cloth 6 is laid at the opening of the first countersunk hole 101. In step S4, a lubricating fiber cloth 6 is laid at the opening of the fourth countersunk hole 301. In step S5, a thermal insulation cotton 401 with a thickness of 15 mm is laid on the upper end surface of the third rod-shaped blank and the upper end surface of the lower flat anvil 4.

[0035] Furthermore, the hydraulic fast forging press is a 45MN hydraulic fast forging press.

[0036] Furthermore, the heating furnace adopts a large industrial resistance furnace, the electric furnace meets or exceeds the Class III standard of the GJB standard, and the accuracy of the electric furnace is ±10°C.

[0037] Example 1

[0038] The original bar diameter is Φ300mm and the height is 2400mm;

[0039] S1: Machining the upper and lower end surfaces of the bar material so that the upper and lower end surfaces of the bar material are perpendicular to the axis of the bar material.

[0040] S2: First fire upsetting, place the two first dies 1 in a heating furnace and preheat to not less than 200°C, place the bar in the heating furnace and heat, the heating temperature is 948-960°C, the heating time is 240-360min; upsetting is carried out on a hydraulic forging machine, before the bar is taken out of the furnace, first install the two preheated first dies 1 on the upper die base and the lower die base of the hydraulic forging machine, lay the lubricating fiber cloth 6 at the first countersunk hole 101 of the first die 1 on the lower die base, and use the loading and unloading machine to take the bar out of the heating furnace. The heated bar is taken out and placed in the first countersunk hole 101, and the total time for bar transfer and positioning is ≤200s; the bar is kept coaxial with the axis of the first countersunk hole 101, and the two ends of the bar are respectively in contact with the bottom surfaces of the two first countersunk holes 101, and pressing is started. The pressing speed is 4-10mm / s, and the pressing time is ≤150s. It is pressed from the length of the bar to 73% of the length of the bar. The deformation of this fire is controlled within the range of 27% (for example: the pressing target value is 1750±10mm), and the first rod-shaped blank is obtained.

[0041] S3: The second roughening process, the first die 1 and the third die 2 are placed in a heating furnace and preheated to not less than 200°C, the first rod-shaped blank is placed in the heating furnace and heated at a temperature of 948-960°C for a heating time of 240-350 minutes; firstly, the preheated third die 2 is installed on the upper die base of the hydraulic fast forging machine, and the first die 1 is installed on the lower die base of the hydraulic fast forging machine; the lubricating fiber cloth 6 is laid at the mouth of the first countersunk hole 101, and the first rod that has been heated is taken out of the heating furnace by a loading and unloading machine; The first rod-shaped blank is placed in the first countersunk hole 101, and the total time for blank transfer and positioning is ≤200s. The first rod-shaped blank is coaxial with the first countersunk hole 101 and the third countersunk hole 201, and the two ends of the first rod-shaped blank are respectively in contact with the bottom surfaces of the first countersunk hole 101 and the third countersunk hole 201, and pressing begins. The pressing speed is 4-10mm / s, and the pressing time is ≤150s. The deformation of this fire is controlled within the range of 26% (for example: the pressing target value is 1300±10mm), and a second rod-shaped blank is obtained;

[0042] S4: The third roughing process, the fourth die 3 and the third die 2 are placed in a heating furnace and preheated to not less than 200°C, the second rod-shaped blank is placed in the heating furnace and heated at a temperature of 948-960°C for a heating time of 280-400 min; firstly, the preheated third die 2 is installed on the upper die base of the hydraulic fast forging machine, and then the fourth die 3 is installed on the lower die base of the hydraulic fast forging machine; a lubricating fiber cloth 6 is laid at the mouth of the fourth countersunk hole 301, and the heated second rod-shaped blank is taken out of the heating furnace by a loading and unloading machine, and the upper and lower end faces are turned so as to be opposite to the upper and lower end faces during the second roughing process, and the loading and unloading machine is used to remove the heated second rod-shaped blank. The machine takes out the second rod-shaped blank that has been heated from the heating furnace and puts it into the fourth countersunk hole 301. The total time for transferring and positioning the second rod-shaped blank is ≤200s. The second rod-shaped blank is coaxial with the fourth countersunk hole 301 and the third countersunk hole 201, and the two ends of the first rod-shaped blank are respectively in contact with the bottom surfaces of the fourth countersunk hole 301 and the third countersunk hole 201, and pressing begins. The pressing speed is 5 to 8 mm / s, and the pressing time is ≤150s. It is pressed from the rod length to 29% of the rod length. The deformation amount of this fire is controlled within the range of 46% (for example: the pressing target value is 700±10mm) to obtain a third rod-shaped blank.

[0043] S5: The fourth fire roughing, the upper flat anvil 5 and the lower flat anvil 4 are placed in a heating furnace and preheated to not less than 200°C, the third rod-shaped blank is returned to the furnace for heating, the heating temperature is 948-960°C, the heating time is 320-500min, the lower flat anvil 4 is installed on the lower die seat of the hydraulic fast forging machine, the upper flat anvil 5 is installed on the upper die seat of the hydraulic fast forging machine, and a 15mm thick insulation cotton 401 is laid on the lower flat anvil 4; then the third rod-shaped blank that has been heated is taken out of the heating furnace using a loading and unloading machine. The blank is placed on the insulation cotton 401 of the lower flat anvil 4, and then the upper end surface of the third rod-shaped blank is also covered with 15mm thick insulation cotton 401. The total time for transporting and positioning the third rod-shaped blank is ≤200s, and pressing begins. The pressing speed is 5-8mm / s, and the pressing time is ≤150s. It is pressed from the length of the rod to 15% of the length of the rod. The deformation of this fire is controlled within the range of 50% (for example: the pressing target value is 350±10mm), and a cake-shaped blank is obtained to be used as a forging die forging blank.

[0044] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for upsetting a titanium alloy with a large aspect ratio, characterized in that: The following steps are included: S1: Machining the upper and lower end surfaces of the bar material so that the upper and lower end surfaces of the bar material are perpendicular to the axis of the bar material; S2: First-time roughing, the bar is placed in a heating furnace for heating, the heating temperature is Tβ-50~Tβ-30℃, and the heating coefficient is 0.8~1.2min / mm; before the bar is taken out of the furnace, two first dies (1) are respectively installed on the lower die seat and the upper die seat of the hydraulic quick forging machine, and the upper surface of the first die (1) is provided with a first countersunk hole (101), and the diameter of the bottom of the first countersunk hole (101) is smaller than the diameter of the opening and larger than the diameter of the bar; the first countersunk holes (101) of the two first dies (1) installed on the lower die seat and the upper die seat are opposite to each other, and the heated bar is placed in the first countersunk hole (101), so that the bar and the first countersunk hole (101) are coaxial, and the two ends of the bar are respectively in contact with the bottom surfaces of the two first countersunk holes (101), and the hydraulic quick forging machine drives the upper die seat to move downward, the moving speed is 4~10mm / s, and the moving distance is 25%~30% of the length of the bar, to obtain a first rod-shaped blank; S3: second-time roughening, the first rod-shaped blank is placed in a heating furnace for heating, the heating temperature is Tβ-50 to Tβ-30°C, and the heating coefficient is 0.4 to 1.2 min / mm; before the first rod-shaped blank is taken out of the furnace, the first die (1) is mounted on the lower die base of the hydraulic quick forging machine, the third die (2) is mounted on the upper die base of the hydraulic quick forging machine, the lower surface of the third die (2) is provided with a third countersunk hole (201), the diameter of the bottom of the third countersunk hole (201) is smaller than the diameter of the opening, the diameter of the opening of the third countersunk hole (201) is larger than the diameter of the opening of the first countersunk hole (101), and the bottom of the third countersunk hole (201) is The diameter of the first countersunk hole (101) is larger than the diameter of the bottom of the first countersunk hole (101); the first countersunk hole (101) and the third countersunk hole (201) are opposite to each other, the first rod-shaped blank is heated and placed in the first countersunk hole (101) and the third countersunk hole (201), the first rod-shaped blank is coaxial with the first countersunk hole (101) and the third countersunk hole (201), and the two ends of the first rod-shaped blank are respectively in contact with the bottom surfaces of the first countersunk hole (101) and the third countersunk hole (201), and the hydraulic fast forging machine drives the third die (2) to move downward at a moving speed of 4 to 10 mm / s and a moving distance of 22% to 27% of the length of the first rod-shaped blank, thereby obtaining a second rod-shaped blank; S4: third-time roughing, the second rod-shaped blank is placed in a heating furnace for heating, the heating temperature is Tβ-50 to Tβ-30°C, and the heating coefficient is 0.4 to 1.2 min / mm; before the second rod-shaped blank is taken out of the furnace, the fourth die (3) is mounted on the lower die base of the hydraulic quick forging machine, and the third die (2) is mounted on the upper die base of the hydraulic quick forging machine, the upper surface of the fourth die (3) is provided with a fourth countersunk hole (301), the diameter of the bottom of the fourth countersunk hole (301) is smaller than the diameter of the opening, the diameter of the opening of the fourth countersunk hole (301) is larger than the diameter of the opening of the third countersunk hole (201), and the diameter of the bottom of the fourth countersunk hole (301) is larger than the diameter of the bottom of the third countersunk hole (201). diameter; the fourth countersunk hole (301) and the third countersunk hole (201) are opposite to each other, the two ends of the heated second rod-shaped blank are respectively placed in the fourth countersunk hole (301) and the third countersunk hole (201), and are in contact with the bottom surfaces of the fourth countersunk hole (301) and the third countersunk hole (201), wherein the end placed in the fourth countersunk hole (301) is the end formed in the third countersunk hole (201) in step S3, the second rod-shaped blank is coaxial with the fourth countersunk hole (301) and the third countersunk hole (201), and the hydraulic fast forging machine drives the third die (2) to move downward at a moving speed of 5 to 8 mm / s, and the moving distance is 43% to 48% of the length of the second rod-shaped blank, thereby obtaining a third rod-shaped blank; S5: The third rod-shaped blank is put into a heating furnace for heating at a temperature of Tβ-50 to Tβ-30°C and a heating coefficient of 0.4 to 1.2 min / mm. Before the third rod-shaped blank is taken out of the furnace, the lower flat anvil (4) is mounted on the lower die base of the hydraulic forging machine, and the upper flat anvil (5) is mounted on the upper die base of the hydraulic forging machine. The heated third rod-shaped blank is placed on the lower flat anvil (4), and the bottom surface of the upper flat anvil (5) is in contact with the upper surface of the third rod-shaped blank. The hydraulic forging machine drives the upper flat anvil (5) to move downward at a speed of 5 to 8 mm / s. The moving distance is 45% to 55% of the length of the third rod-shaped blank, and a cake-shaped blank is obtained.

2. A method for upsetting a titanium alloy with a large aspect ratio as claimed in claim 1, characterized in that: The first mold (1), the third mold (2), the fourth mold (3), the upper anvil (5) and the lower anvil (4) are all placed in a furnace and preheated to ≥200°C before use.

3. The method for upsetting a titanium alloy with a large aspect ratio as claimed in claim 1, characterized in that: The time from when the bar material comes out of the furnace to when the positioning is completed, the time from when the first rod-shaped blank comes out of the furnace to when the positioning is completed, the time from when the second rod-shaped blank comes out of the furnace to when the positioning is completed, and the time from when the third rod-shaped blank comes out of the furnace to when the positioning is completed are all no more than 200 seconds.

4. The method for upsetting a titanium alloy with a large aspect ratio as claimed in claim 1, characterized in that: In step S2, after the first die (1) is installed on the lower die base of the hydraulic fast forging machine, a lubricating fiber cloth (6) is laid at the opening of the first countersunk hole (101). In step S3, a lubricating fiber cloth (6) is laid at the opening of the first countersunk hole (101). In step S4, a lubricating fiber cloth (6) is laid at the opening of the fourth countersunk hole (301). In step S5, a heat-insulating cotton (401) with a thickness of 15 mm is laid on the upper end surface of the third rod-shaped blank and the upper end surface of the lower flat anvil (4).

5. The method for upsetting a titanium alloy with a large aspect ratio as claimed in claim 1, characterized in that: The hydraulic fast forging press is a 45MN hydraulic fast forging press.

6. The method for upsetting a titanium alloy with a large aspect ratio as claimed in claim 1, characterized in that: The heating furnace adopts a large industrial resistance furnace, which meets or exceeds the Class III standard of the GJB standard and has an accuracy of ±10°C.

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