A forming method for forging titanium alloy Ti175 bars

Abstract

This invention discloses a forging method for titanium alloy Ti175 bars. By precisely setting the temperatures for blanking, forging, and forming, and quantitatively controlling key parameters during the forging process, such as transfer time, deformation, and reduction speed, the method ensures that the material achieves ideal internal structure and properties during the forging and cooling processes. Furthermore, the method includes heat treatment, physical and chemical testing, machining, and corrosion and flaw detection. By precisely controlling key parameters during the forging process, the device optimizes the material's internal structure, effectively promoting grain recrystallization and refinement, and avoiding excessive grain growth or uneven grain distribution. This not only improves the overall quality and performance of the product, but also optimizes the production process and reduces costs.

Description

Technical Field

[0001] The invention relates to the field of forging hot processing, in particular to a forming method for forging a titanium alloy Ti175 bar. Background Art

[0002] Titanium alloy Ti175 is an alloy material with titanium as its main component, which also contains various additive elements such as aluminum (Al), molybdenum (Mo), chromium (Zr), tin (Sn), tungsten (W), and silicon (Si). The proportions of these elements are 6.2%-7.50% aluminum, 3.5%-4.50% molybdenum, 3.5%-4.50% chromium, 1.5%-3.0% tin, 0.9%-2.00% tungsten, and 0.15%-0.35% silicon. The remaining components are titanium and a small amount of impurities. Due to its high strength, low density and good corrosion resistance, Ti175 alloy has broad application prospects in the aerospace field, industrial equipment and other fields.

[0003] In the traditional forging process of titanium alloy Ti175 bars, simple forging is usually performed according to the required size requirements. However, this method has less control over the technical parameters during the forging process, resulting in insufficient research on the internal structure and performance of the final product. Since the internal structure and performance of titanium alloy Ti175 bars are crucial to the quality of the final product, it is necessary to ensure that the forging technology is finely controlled during the forging and subsequent heat treatment processes and that the bars after forging are strictly quality tested, so as to improve the internal structure and performance of titanium alloy Ti175 bars and meet the high-demand applications. Summary of the Invention

[0004] The object of the present invention is to provide a forming method for forging titanium alloy Ti175 bars, which optimizes the internal structure of the bars by precisely controlling the technical parameters during the forging process, thereby improving the quality and performance of the final product.

[0005] In order to solve the above technical problems, the present invention provides a forming method for forging a titanium alloy Ti175 bar, comprising the following steps:

[0006] Forging temperature setting, including the setting of the temperature of the blank forging, the temperature of the reforming forging and the temperature of the forming forging. The three types of temperature settings include four firing times, and each firing time includes the temperature setting of preheating and bar heating with the furnace;

[0007] Forging parameter control, including control of parameters of the bar during the four firing processes of cogging forging, reforming forging, and forming forging. The parameters of the cogging forging and reforming forging include transfer time, feed amount, deformation amount, and forging time. The parameters of the forming forging include pressing speed, pressing amount, deformation amount, and hammering interval time.

[0008] Post-forging cooling, including cooling the bar in stages during the forging process;

[0009] Heat treatment is used to improve the mechanical and physical properties of the rod.

[0010] Optionally, setting the temperature of the blank forging includes:

[0011] In the first firing, the furnace temperature is preheated to 700-850°C, the rods are added and the temperature is raised to 1120-1160°C as the furnace is heated;

[0012] In the second firing, the furnace temperature is preheated to 710-840°C, the bars forged in the first firing are added and the temperature is raised to 1080-1120°C as the furnace is heated;

[0013] In the third firing, the furnace temperature is preheated to 720-830°C, the bars forged in the second firing are added and the temperature is raised to 1000-1040°C.

[0014] In the fourth firing, the furnace temperature is preheated to 730-820° C., the bars forged in the third firing are added, and the temperature is raised to 960-1000° C. along with the furnace temperature.

[0015] Optionally, setting the temperature of the reforming forging includes:

[0016] In the first firing, the furnace temperature is preheated to 800-850°C, the rods are added and the temperature is raised to 900-950°C as the furnace is heated;

[0017] In the second firing, the furnace temperature is preheated to 750-800°C, the bars forged in the first firing are added and the temperature is raised to 850-900°C as the furnace is heated;

[0018] In the third firing, the furnace temperature is preheated to 700-750°C, the bars forged in the second firing are added, and the temperature is raised to 800-850°C along with the furnace temperature;

[0019] In the fourth firing, the furnace temperature is preheated to 650-700° C., the bars forged in the third firing are added, and the temperature is raised to 750-800° C. along with the furnace.

[0020] Optionally, setting the temperature of the forming forging includes:

[0021] In the first firing, the furnace temperature is preheated to 750-800°C, the rods are added and the temperature is raised to 800-850°C as the furnace heats up;

[0022] In the second firing, the furnace temperature is preheated to 700-750°C, the bars forged in the first firing are added and the temperature is raised to 750-800°C as the furnace is heated;

[0023] In the third firing, the furnace temperature is preheated to 650-700°C, the bars forged in the second firing are added and the furnace temperature is raised to 700-750°C;

[0024] In the fourth firing, the furnace temperature is preheated to 600-650° C., the bars forged in the third firing are added and the temperature is raised to 650-700° C. along with the furnace temperature.

[0025] Optionally, during the blank forging process, the control of the parameters includes:

[0026] In the first fire with the blanking forging temperature set, the transfer time of the bar is 0 to 60 seconds, the feed amount is 425 mm, the deformation amount is 45 to 50%, and the forging time is 0 to 180 seconds;

[0027] In the second fire of the blanking forging temperature setting, the transfer time of the bar is 0 to 50 seconds, the feed amount is 400 mm, the deformation amount is 40 to 45%, and the forging time is 0 to 165 seconds;

[0028] In the third fire with the blanking forging temperature set, the transfer time of the bar is 0 to 45 seconds, the feed amount is 375 mm, the deformation amount is 35 to 40%, and the forging time is 0 to 150 seconds;

[0029] In the fourth fire with the blanking forging temperature set, the transfer time of the bar is 0 to 40 seconds, the feed amount is 350 mm, the deformation amount is 30 to 35%, and the forging time is 0 to 135 seconds.

[0030] Optionally, during the reforging process, the control of the parameters includes:

[0031] In the first fire with the reforging temperature set, the transfer time of the bar is 0 to 45 seconds, the feed amount is 0 to 250 mm, the deformation amount is 40 to 45%, and the forging time is 0 to 170 seconds;

[0032] In the second fire with the reforging temperature set, the transfer time of the bar is 0 to 40 seconds, the feed amount is 0 to 230 mm, the deformation amount is 35 to 40%, and the forging time is 0 to 150 seconds;

[0033] In the third fire with the forging temperature set, the transfer time of the bar is 0 to 35 seconds, the feed amount is 0 to 210 mm, the deformation amount is 30 to 35%, and the forging time is 0 to 130 seconds;

[0034] In the fourth fire with the forging temperature set, the transfer time of the bar is 0 to 30 seconds, the feed amount is 0 to 200 mm, the deformation amount is 25 to 30%, and the forging time is 0 to 110 seconds.

[0035] Optionally, during the forming and forging process, the control of the parameters includes:

[0036] In the first fire of the forming forging temperature setting, the pressing speed is 25-30 mm / s, the pressing amount a is 60-70 mm, the deformation is 25-30%, and the hammering interval time is 3-4 s;

[0037] In the second fire of the forming forging temperature setting, the pressing speed is 20-25 mm / s, the pressing amount a is 50-60 mm, the deformation is 20-25%, and the hammering interval time is 3-4 s;

[0038] In the third fire of the forming forging temperature setting, the pressing speed is 15-20 mm / s, the pressing amount a is 40-50 mm, the deformation amount is 15-20%, and the hammering interval time is 1-2 s;

[0039] In the fourth fire with the forming forging temperature setting, the pressing speed is 10-15 mm / s, the pressing amount a is 30-40 mm, the deformation amount is 10-15%, and the hammer gap time is 1-2 s.

[0040] Optionally, the staged cooling method includes adopting a natural cooling method after the blanking forging is completed, adopting a forced ventilation cooling method after the reforming forging is completed, and adopting a liquid cooling method after the forming forging is completed.

[0041] Optionally, the heat treatment includes primary annealing and secondary annealing;

[0042] The primary annealing comprises placing the rod into a furnace at 0-800° C., heating the rod to 867-877° C., and maintaining the temperature within the range of 867-877° C. for 108-132 minutes. After the temperature is maintained, the rod is taken out of the furnace and cooled in air.

[0043] The secondary annealing includes placing the rod into a furnace at 0-500° C., heating the rod to 530-550° C. with the furnace, and keeping the temperature within the range of 530-550° C. for 345-375 minutes. After the temperature is kept, the rod is taken out of the furnace and cooled in air.

[0044] Optionally, physical and chemical tests, mechanical processing, corrosion and flaw detection are also included; the physical and chemical tests are used to evaluate the chemical and physical properties of the rod; the mechanical processing is used to accurately determine the size and surface finish of the rod; the corrosion and flaw detection are used to evaluate the corrosion resistance and integrity of the rod in a specific environment.

[0045] Compared with the prior art, the present invention has at least the following beneficial effects:

[0046] The present invention effectively improves the original undeformed grain structure of the titanium alloy Ti175 remaining after smelting by precisely controlling the technical parameters in the forging process, such as temperature, deformation, forging speed, etc., thereby significantly improving the internal structure qualification rate of the bar, effectively reducing the energy consumption in the forging process, saving production costs and improving economic benefits; secondly, by comprehensively considering the mutual influence and matching relationship of various technical parameters in the forging process, the refined management of the forging process is achieved, and the overall performance of the product is further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 is a flow chart of a molding method according to an embodiment of the present invention;

[0048] Figure 2 This is a block diagram of the components of the forging temperature setting in one embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following is a more detailed description of a titanium alloy Ti175 bar forging forming method of the present invention with reference to a schematic diagram, wherein a preferred embodiment of the present invention is shown. It should be understood that those skilled in the art may modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being generally known to those skilled in the art and not as limiting the present invention.

[0050] The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are greatly simplified and not to exact scale, and are provided solely for the purpose of assisting in the description of the embodiments of the present invention.

[0051] like Figures 1 to 2 As shown, the embodiment of the present invention provides a forging forming method of titanium alloy Ti175 bar, comprising the following steps:

[0052] Forging setting temperature, including setting the temperature of blank forging, temperature of reforming forging and temperature of forming forging. The setting of the three types of temperature includes four firing times, and each firing time includes the temperature setting of preheating and bar heating with furnace;

[0053] Forging parameter control, including control of parameters of the bar during the four firings of cogging forging, reforming forging, and forming forging, wherein the parameters of the cogging forging and reforming forging include transfer time, feed amount, deformation amount r, and forging time, and the parameters of the forming forging include pressing speed, pressing amount a, deformation amount r, and hammering interval time;

[0054] Post-forging cooling, including cooling the bar in stages during the forging process;

[0055] Heat treatment is used to improve the mechanical and physical properties of the rod.

[0056] In this embodiment, the forming method is used to forge titanium alloy Ti175 bars, and the specific process is as follows:

[0057] Step 1: Forging

[0058] In the first firing, the furnace temperature is preheated to 700-850°C, the rods are added and the temperature is raised to 1120-1160°C as the furnace is heated.

[0059] In the first fire of the blank forging, the control of the parameters includes the transfer time of the bar being 0 to 60 seconds, the feed amount being 425 mm, the deformation amount being 45 to 50%, and the forging time being 0 to 180 seconds.

[0060] Specifically, during the first heat of the cogging forging of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 840°C with the furnace, where it is maintained for 120 minutes. Subsequently, the temperature is continued to be heated to 1165°C, the phase transition point, and maintained at this high temperature for 555 minutes. During the first heat of the cogging forging, the transfer time is required to be no more than 60 seconds, the feed amount is 425 mm, the deformation amount is 46%, and the entire process must be completed within 180 seconds.

[0061] The specific blank forging process is: first, the bar with a diameter of 690 mm and a length of 900 mm is axially upset to make the diameter of the bar reach 700 mm and the length of 680±5 mm; then, the bar is forged in the axis to be squared and drawn to reach a diameter of 585 mm and a length of 995±5 mm; then, the bar is axially upset again to make the diameter reach 790 mm and the length reach 540±5 mm; finally, the bar is forged in the axis to be drawn to reach a diameter of 585 mm and a length of 995±5 mm.

[0062] In the second firing, the furnace temperature is preheated to 710-840° C., the bar material forged in the first firing is added, and the temperature is raised to 1080-1120° C. along with the furnace temperature.

[0063] In the second fire with the blanking forging temperature set, the control of the parameters includes the transfer time of the bar being 0 to 50 seconds, the feed amount being 400 mm, the deformation amount being 40 to 45%, and the forging time being 0 to 165 seconds.

[0064] Specifically, during the second heat of the cogging forging of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 830°C with the furnace, where it is maintained for 120 minutes. Subsequently, the temperature is continued to be heated to 1165°C, the phase transition point, and maintained at this high temperature for 430 minutes. During the second heat of the cogging forging, the transfer time is required to be no more than 50 seconds, the feed amount is 400 mm, the deformation amount is 46%, and the entire process must be completed within 165 seconds.

[0065] The specific blank forging process is: first, the bar with a diameter of 585 mm and a length of 995 mm is axially upset to make the diameter of the bar reach 755 mm and the length of 590±5 mm; then, the bar is forged in the axis to be squared and drawn to reach a diameter of 490 mm and a length of 1400±5 mm; then, the bar is axially upset again to make the diameter reach 755 mm and the length reach 590±5 mm; finally, the bar is forged in the axis to be squared and drawn to reach a diameter of 490 mm and a length of 1400±5 mm.

[0066] In the third fire, the furnace temperature is preheated to 720-830°C, the bar forged in the second fire is added, and the temperature is raised to 1000-1040°C along with the furnace temperature;

[0067] In the third fire with the blanking forging temperature set, the control of the parameters includes the transfer time of the bar being 0 to 45 seconds, the feed amount being 375 mm, the deformation amount being 35 to 40%, and the forging time being 0 to 150 seconds.

[0068] Specifically, during the third heat of the cogging forging of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 820°C with the furnace, where it is maintained for 120 minutes. Subsequently, the temperature is continued to be heated to 1035°C, the phase transition point, and maintained at this high temperature for 400 minutes. During the third heat of the cogging forging, the transfer time is required to be no more than 45 seconds, the feed amount is 375 mm, the deformation amount is 36%, and the entire process must be completed within 150 seconds.

[0069] The specific blanking forging process is as follows: first, the bar with a diameter of 490 mm and a length of 1400 mm is axially upset to make the diameter of the bar reach 610 mm and the length of 900±5 mm; then, the bar is forged in the axis to be square-drawn to reach a diameter of 525 mm and a length of 1225±5 mm; then, the bar is axially upset again to make the diameter reach 610 mm and the length reach 900±5 mm; finally, the bar is forged in the axis to be square-drawn to reach a diameter of 525 mm and a length of 1225±5 mm.

[0070] In the fourth firing, the furnace temperature is preheated to 730-820° C., the bar material forged in the third firing is added, and the temperature is raised to 960-1000° C. with the furnace.

[0071] In the fourth fire with the blank forging temperature set, the control of the parameters includes the transfer time of the bar being 0 to 40 seconds, the feed amount being 350 mm, the deformation amount being 30 to 35%, and the forging time being 0 to 135 seconds.

[0072] Specifically, during the fourth heat of the cogging forging of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 810°C with the furnace, where it is maintained for 120 minutes. Subsequently, the temperature is continued to be heated to 995°C, the phase transition point, and maintained at this high temperature for 575 minutes. During the fourth heat of the cogging forging, the transfer time is required to be no more than 40 seconds, the feed amount is 350 mm, the deformation amount is 31%, and the entire forging process must be completed within 135 seconds.

[0073] The specific blank forging process is: first, the bar with a diameter of 525 mm and a length of 1225 mm is axially upset to make the diameter of the bar reach 630 mm and the length of 845±5 mm; then, the bar is axially forged and drawn to make the diameter reach 550 mm and the length reach 1105±5 mm; then, the bar is axially upset again to make the diameter reach 630 mm and the length reach 845±5 mm; finally, the bar is square forged and drawn to make the diameter reach 550 mm and the length reach 1105±5 mm.

[0074] Step 2: Forging

[0075] In the first firing, the furnace temperature is preheated to 800-850°C, and the rod is heated to 900-950°C along with the furnace.

[0076] In the first fire of the reforming forging, the transfer time of the bar is 0 to 45 seconds, the feed amount is 0 to 250 mm, the deformation amount is 40 to 45%, and the forging time is 0 to 170 seconds.

[0077] Specifically, during the first forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 840°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to 940°C, the phase transition point, and maintained at this high temperature for 575 minutes. During the first forging process, the transfer time is required to be no more than 45 seconds, the feed amount is required to be no more than 250 mm, the deformation is required to be 41%, and the entire forging process must be completed within 170 seconds.

[0078] The specific billet reforming and forging process is as follows: first, the bar with a diameter of 550 mm and a length of 1105 mm is axially upset to make the diameter of the bar reach 720 mm and the length of 650±5 mm; then, the bar is axially forged and drawn to make the diameter reach 605 mm and the length reach 915±5 mm; then, the bar is axially upset again to make the diameter reach 720 mm and the length reach 650±5 mm; finally, the bar is square forged and drawn to make the diameter reach 605 mm and the length reach 915±5 mm.

[0079] In the second firing, the furnace temperature is preheated to 750-800° C., the bars forged in the first firing are added and the temperature is raised to 850-900° C. along with the furnace.

[0080] In the second fire of the forging temperature setting, the control parameters include the transfer time of the bar being 0 to 40 seconds, the feed amount being 0 to 230 mm, the deformation amount being 35 to 40%, and the forging time being 0 to 150 seconds.

[0081] Specifically, during the second forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 790°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to 890°C, the phase transition point, and maintained at this high temperature for 575 minutes. During the second forging process, the transfer time is required to be no more than 40 seconds, the feed amount is required to be no more than 230 mm, the deformation is required to be 36%, and the entire process must be completed within 150 seconds.

[0082] The specific billet reforming and forging process is as follows: first, the bar with a diameter of 605 mm and a length of 915 mm is axially upset to make the diameter of the bar reach 755 mm and the length 590±5 mm; then, the bar is axially forged and drawn to make the diameter reach 645 mm and the length 805±5 mm; then, the bar is axially upset again to make the diameter reach 755 mm and the length 590±5 mm; finally, the bar is square forged and drawn to make the diameter reach 645 mm and the length 805±5 mm.

[0083] In the third fire, the furnace temperature is preheated to 700-750° C., the bars forged in the second fire are added and the temperature is raised to 800-850° C. with the furnace.

[0084] In the third fire with the forging temperature setting, the control parameters include the transfer time of the bar being 0 to 35 seconds, the feed amount being 0 to 210 mm, the deformation amount being 30 to 35%, and the forging time being 0 to 130 seconds.

[0085] Specifically, during the third forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 740°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to 840°C, the phase transition point, and maintained at this high temperature for 575 minutes. During the third forging process, the transfer time is required to be no more than 35 seconds, the feed amount is required to be no more than 210 mm, the deformation is required to be 31%, and the entire process must be completed within 130 seconds.

[0086] The specific billet reforming and forging process is as follows: first, the bar with a diameter of 645 mm and a length of 805 mm is axially upset to make the diameter of the bar reach 770 mm and the length 560±5 mm; then, the bar is axially forged and drawn to make the diameter reach 670 mm and the length 740±5 mm; then, the bar is axially upset again to make the diameter reach 770 mm and the length 560±5 mm; finally, the bar is square forged and drawn to make the diameter reach 670 mm and the length 740±5 mm.

[0087] In the fourth fire, the furnace temperature is preheated to 650-700° C., the bars forged in the third fire are added and the temperature is raised to 750-800° C. with the furnace.

[0088] In the fourth fire of the forging temperature setting, the control parameters include the transfer time of the bar being 0 to 30 seconds, the feed amount being 0 to 200 mm, the deformation amount being 25 to 30%, and the forging time being 0 to 110 seconds.

[0089] Specifically, during the fourth forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 700°C, and gradually heated to 690°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to the phase transition point of 790°C with the furnace, and maintained at this high temperature for 575 minutes. During the fourth forging process, the transfer time is required to be no more than 30 seconds, the feed amount is required to be no more than 200 mm, the deformation is required to be 26%, and the entire process must be completed within 110 seconds.

[0090] The specific billet reforming and forging process is as follows: first, the bar with a diameter of 670 mm and a length of 740 mm is axially upset to make the diameter of the bar reach 780 mm and the length of 550±5 mm; then, the bar is subjected to in-axis square forging and drawing to reach a diameter of 650 mm and a length of 720±5 mm; then, the bar is axially upset again to make the diameter reach 780 mm and the length reach 550±5 mm; finally, the bar is square forged and drawn to reach a diameter of 650 mm and a length of 720±5 mm.

[0091] Step 3: Forming and Forging

[0092] In the first firing, the furnace temperature is preheated to 750-800°C, the rods are added and the temperature is raised to 800-850°C as the furnace is heated.

[0093] In the first fire with the forming forging temperature set, the control parameters include the pressing speed of 25 to 30 mm / s, the pressing amount of 60 to 70 mm, the deformation amount of 25 to 30%, and the hammer gap time of 3 to 4 s.

[0094] Specifically, during the first forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 600°C, and gradually heated to 790°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to the phase transition point of 840°C with the furnace, and kept at this high temperature for 575 minutes. In the specific process step of forging the titanium alloy Ti175 bar for the first time, the pressing speed is 25 to 30 mm / s to ensure uniform deformation of the material; the pressing amount is 60 to 70 mm, the deformation amount is 29%, and the hammering interval time is 3 to 4 seconds, allowing the bar to have enough time for stress release and temperature adjustment between each hammering.

[0095] The specific forming and forging process includes: first, forging the bar with a diameter of 650 mm and a length of 720 mm to make the diameter of the bar reach 600 mm and the length reach 935±5 mm; then, the bar is forged in the axis to be squared and drawn to reach a diameter of 530 mm and a length of 1200±5 mm.

[0096] In the second firing, the furnace temperature is preheated to 700-750°C, the bar forged in the first firing is added, and the temperature is raised to 750-800°C as the furnace is heated;

[0097] In the second fire of the forming forging temperature setting, the parameter control includes the pressing speed of 20-25 mm / s, the pressing amount of 50-60 mm, the deformation of 20-25%; and the hammer gap time of 3-4 seconds;

[0098] Specifically, during the second forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 600°C, and gradually heated to 740°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to the phase transition point of 790°C with the furnace, and kept at this high temperature for 200 minutes. In the specific step of forging the titanium alloy Ti175 bar for the second time, the pressing speed is 20 to 25 mm / s to ensure uniform deformation of the material; the pressing amount is 50 to 60 mm, the deformation amount is 24%, and the hammering interval time is 3 to 4 seconds, allowing the bar to have enough time for stress release and temperature adjustment between each hammering.

[0099] The specific forming and forging process includes: first, forging the bar with a diameter of 530 mm and a length of 1200 mm to make the diameter of the bar reach 480 mm and the length of 1730±5 mm; then, the bar is forged in the axis to be drawn to a diameter of 440 mm and a length of 1730±5 mm.

[0100] In the third fire, the furnace temperature is preheated to 650-700°C, the bar forged in the second fire is added and the temperature is raised to 700-750°C along with the furnace;

[0101] In the third fire with the forming forging temperature setting, the control parameters include the pressing speed of 15 to 20 mm / s, the pressing amount of 40 to 50 mm, the deformation amount of 15 to 20%, and the hammer gap time of 1 to 2 s.

[0102] Specifically, during the third forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 600°C, and gradually heated to 690°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to the phase transition point of 745°C with the furnace, and kept at this high temperature for 575 minutes. In the specific step of forging the titanium alloy Ti175 bar for the third time, the pressing speed is 15 to 20 mm / s to ensure uniform deformation of the material; the pressing amount is 40 to 50 mm, the deformation amount is 20%, and the hammering interval time is 1 to 2 seconds, allowing the bar to have enough time for stress release and temperature adjustment between each hammering.

[0103] The specific forming and forging process includes: first, forging the bar with a diameter of 440 mm and a length of 1730 mm to make the diameter of the bar reach 400 mm and the length of 2080±5 mm; then, forging and drawing the bar to a diameter of 365 mm and a length of 2500±5 mm.

[0104] In the fourth firing, the furnace temperature is preheated to 600-650° C., the bars forged in the third firing are added and the temperature is raised to 650-700° C. as the furnace is heated.

[0105] In the fourth fire of the forming forging temperature setting, the control parameters include the pressing speed of 10-15 mm / s, the pressing amount of 30-40 mm, the deformation amount of 10-15%, and the hammer gap time of 1-2 s.

[0106] Specifically, during the fourth forging process of the titanium alloy Ti175 bar, the bar is first placed in a furnace at a temperature not exceeding 600°C, and gradually heated to 640°C with the furnace, and maintained at this temperature for 120 minutes. Subsequently, the temperature is continued to be heated to the phase transition point of 690°C with the furnace, and kept at this high temperature for 575 minutes. In the specific step of forging the titanium alloy Ti175 bar for the fourth time, the pressing speed is 10 to 15 mm / s to ensure uniform deformation of the material; the pressing amount is 30 to 40 mm, the deformation amount is 15%, and the hammering interval time is 1 to 2 seconds, allowing the bar to have enough time for stress release and temperature adjustment between each hammering.

[0107] The specific forming and forging process includes: first, forging the rod with a diameter of 440 mm and a length of 1730 mm to make the diameter of the rod reach 365 mm and the length of 2500±5 mm; then, forging and drawing the rod to a diameter of 365 mm and a length of 3010±5 mm; thereafter, dividing the rod into two pieces, each with a diameter of 330 mm and a length of 1500±5 mm; finally, using a special hammer to axially draw each piece of the rod to make the diameter of the rod 272~282 mm and the length 2740~2760 mm.

[0108] In this embodiment, the staged cooling method includes natural cooling after the blanking forging is completed, forced ventilation cooling after the reforming forging is completed, and liquid cooling after the forming forging is completed.

[0109] In this embodiment, the heat treatment includes primary annealing and secondary annealing, and is performed according to industry standards.

[0110] The primary annealing comprises placing the rod into a furnace at 0-800° C., heating the rod to 867-877° C. with the furnace, and keeping the temperature within the range of 867-877° C. for 108-132 minutes. After the temperature is kept, the rod is taken out of the furnace and cooled in air.

[0111] The secondary annealing includes placing the rod into a furnace at 0-500° C., heating the rod to 530-550° C. with the furnace, and keeping the temperature within the range of 530-550° C. for 345-375 minutes. After the temperature is kept, the rod is taken out of the furnace and cooled in air.

[0112] In the four steps of the forming forging, if one forging is sufficient to ensure that the final performance of the bar reaches the expected standard, only one annealing process may be performed during the heat treatment process.

[0113] In this embodiment, the forming method further includes physical and chemical testing, mechanical processing, and corrosion and flaw detection. The physical and chemical testing is used to evaluate the chemical and physical properties of the rod; the mechanical processing is used to accurately determine the dimensions and surface finish of the rod; and the corrosion and flaw detection is used to evaluate the corrosion resistance and integrity of the rod under specific conditions.

[0114] The physical and chemical tests include chemical composition analysis, mechanical property testing, and high-magnification and low-magnification structural inspections. A sample with a diameter of 130 mm and a height of 150 mm is selected from below the end of the bar in each batch of furnace for physical and chemical testing.

[0115] The machining includes turning, grinding or other cutting operations on the outer cylindrical surface and two end faces of the bar, so that the roughness of the outer cylindrical surface and two end faces of the bar reaches Ra3.2.

[0116] The corrosion test is carried out by performing two low-magnification inspections on the bar according to the standard, and the flaw detection test is carried out by performing ultrasonic flaw detection acceptance on the bar according to the standard.

[0117] The following are four finished products forged according to the forming method, and the test results at room temperature are shown in Table 1.

[0118] Table 1

[0119]

[0120] The standards under normal temperature conditions are: tensile strength (Rm) ≥ 1050Mpa, yield strength (Rp0.2) ≥ 900MPa, elongation (A) ≥ 10%, cross-sectional shrinkage (Z) ≥ 20%, fracture toughness (KIC) ≥ 24MPa√m.

[0121] The following are two finished products forged according to the forming method, and the test results at a high temperature of 550°C are shown in Table 2.

[0122] Table 2

[0123]

[0124] The standards under high temperature conditions of 550℃ are: tensile strength (Rm) ≥ 750Mpa, yield strength (Rp0.2) ≥ 580MPa, elongation (A) ≥ 12%, and section shrinkage (Z) ≥ 20%.

[0125] As can be seen from Tables 1 and 2, the titanium alloy Ti175 rod forged according to the forming method has various indicators that are better than the standard requirements at room temperature and high temperature, that is, the forming method can effectively improve the performance of the rod, making it suitable for occasions with high requirements on strength, plasticity and toughness.

[0126] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A forming method for forging titanium alloy Ti175 bars, characterized in that: The steps include: Forging temperature setting, including the setting of the temperature of the blank forging, the temperature of the reforming forging and the temperature of the forming forging. The three types of temperature settings include four firing times, and each firing time includes the temperature setting of preheating and bar heating with the furnace; Forging parameter control, including control of parameters of the bar during the four firing processes of cogging forging, reforming forging, and forming forging. The parameters of the cogging forging and reforming forging include transfer time, feed amount, deformation amount, and forging time. The parameters of the forming forging include pressing speed, pressing amount, deformation amount, and hammering interval time. Post-forging cooling, including cooling the bar in stages during the forging process; Heat treatment to improve the mechanical and physical properties of the rod; Wherein, setting the temperature of the blank forging includes: In the first firing, the furnace temperature is preheated to 700-850°C, the rods are added and the temperature is raised to 1120-1160°C as the furnace is heated; In the second firing, the furnace temperature is preheated to 710-840°C, the bars forged in the first firing are added, and the temperature is raised to 1080-1120°C as the furnace is heated; In the third fire, the furnace temperature is preheated to 720-830°C, the bars forged in the second fire are added and the temperature is raised to 1000-1040°C. In the fourth fire, the furnace temperature is preheated to 730-820°C, the bars forged in the third fire are added, and the temperature is raised to 960-1000°C. Setting the temperature of the reforming forging includes: In the first firing, the furnace temperature is preheated to 800-850°C, the rods are added and the temperature is raised to 900-950°C as the furnace is heated; In the second firing, the furnace temperature is preheated to 750-800°C, the bars forged in the first firing are added, and the temperature is raised to 850-900°C as the furnace is heated; In the third fire, the furnace temperature is preheated to 700-750°C, the bars forged in the second fire are added and the temperature is raised to 800-850°C. In the fourth firing, the furnace temperature is preheated to 650-700°C, the bars forged in the third firing are added, and the temperature is raised to 750-800°C. Setting the temperature of the forming forging includes: In the first firing, the furnace temperature is preheated to 750-800°C, the rods are added and the temperature is raised to 800-850°C as the furnace is heated; In the second firing, the furnace temperature is preheated to 700-750°C, the bars forged in the first firing are added, and the temperature is raised to 750-800°C as the furnace is heated; In the third firing, the furnace temperature is preheated to 650-700°C, the bars forged in the second firing are added, and the temperature is raised to 700-750°C as the furnace is heated; In the fourth firing, the furnace temperature is preheated to 600-650°C, the bars forged in the third firing are added, and the temperature is raised to 650-700°C as the furnace is heated; During the blank forging process, the control of the parameters includes: In the first fire of the blanking forging temperature setting, the transfer time of the bar is 0-60 seconds, the feed amount is 425 mm, the deformation amount is 45-50%, and the forging time is 0-180 seconds; In the second fire of the blanking forging temperature setting, the transfer time of the bar is 0-50 seconds, the feed amount is 400 mm, the deformation amount is 40-45%, and the forging time is 0-165 seconds; In the third fire of the blanking forging temperature setting, the transfer time of the bar is 0-45 seconds, the feed amount is 375 mm, the deformation amount is 35-40%, and the forging time is 0-150 seconds; In the fourth fire of the blanking forging temperature setting, the transfer time of the bar is 0-40 seconds, the feed amount is 350 mm, the deformation amount is 30-35%, and the forging time is 0-135 seconds; During the reforming forging process, the control of the parameters includes: In the first fire of the reforging temperature setting, the transfer time of the bar is 0-45 seconds, the feed amount is 0-250 mm, the deformation amount is 40-45%, and the forging time is 0-170 seconds; In the second fire of the reforging temperature setting, the transfer time of the bar is 0-40 seconds, the feed amount is 0-230 mm, the deformation amount is 35-40%, and the forging time is 0-150 seconds; In the third fire with the forging temperature setting, the transfer time of the bar is 0-35 seconds, the feed amount is 0-210 mm, the deformation amount is 30-35%, and the forging time is 0-130 seconds; In the fourth fire of the forging temperature setting, the transfer time of the bar is 0-30 seconds, the feed amount is 0-200 mm, the deformation amount is 25-30%, and the forging time is 0-110 seconds; During the forming and forging process, the control of the parameters includes: In the first fire of the forming forging temperature setting, the pressing speed is 25-30 mm / s, the pressing amount a is 60-70 mm, the deformation is 25-30%, and the hammering interval time is 3-4 s; In the second fire of the forming forging temperature setting, the pressing speed is 20-25 mm / s, the pressing amount a is 50-60 mm, the deformation is 20-25%, and the hammering interval time is 3-4 s; In the third fire of the forming forging temperature setting, the pressing speed is 15-20 mm / s, the pressing amount a is 40-50 mm, the deformation is 15-20%, and the hammering interval time is 1-2 s; In the fourth fire with the forming forging temperature setting, the pressing speed is 10~15mm / s, the pressing amount a is 30~40mm, the deformation amount is 10~15%, and the hammer gap time is 1~2s.

2. The molding method according to claim 1, wherein The staged cooling method includes adopting a natural cooling method after the blanking forging is completed, adopting a forced ventilation cooling method after the reforming forging is completed, and adopting a liquid cooling method after the forming forging is completed.

3. The molding method according to claim 1, wherein: The heat treatment includes primary annealing and secondary annealing; The primary annealing comprises placing the rod into a furnace at 0-800° C., heating the rod to 867-877° C., and maintaining the temperature within the range of 867-877° C. for 108-132 minutes. After the temperature is maintained, the rod is taken out of the furnace and cooled in air. The secondary annealing includes placing the rod into a furnace at 0-500° C., heating the rod to 530-550° C. with the furnace, and keeping the temperature within the range of 530-550° C. for 345-375 minutes. After the temperature is kept, the rod is taken out of the furnace and cooled in air.

4. The molding method according to claim 1, wherein: It also includes physical and chemical testing, machining, corrosion and flaw detection; the physical and chemical testing is used to evaluate the chemical and physical properties of the rod; the machining is used to accurately measure the size and surface finish of the rod; the corrosion and flaw detection is used to evaluate the corrosion resistance and integrity of the rod in a specific environment.

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