A method for manufacturing a titanium alloy large-size bar

Abstract

The application belongs to the technical field of non-ferrous metal processing, and particularly relates to a preparation method of titanium alloy large-size rod. The application increases the nucleation rate of a blank by water cooling, improves the nucleation quantity and uniform distribution of the material, and can improve the uniformity of the overall structure and performance of the material. The small press machine reduces the economic cost, and compared with the 80MN and 100MN press machines for preparing the rod, the application can realize the same mechanical properties and surpass the structure uniformity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous metal processing, and particularly relates to a preparation method of titanium alloy large-size rod. BACKGROUND

[0002] Currently, the preparation of high-quality large-size titanium alloy rod mainly relies on fast forging machine forging, wherein the grain nucleation and growth of titanium alloy is a key factor affecting the uniformity of the titanium alloy rod. In the past preparation scheme, mainly relies on improving the capacity of the forging equipment, providing higher pressure, to improve the nucleation rate of titanium alloy, and then improve the uniformity of the titanium alloy rod organization; this method can realize the production of high-quality large-size titanium alloy rod, but it needs to invest a large amount of funds, site, equipment and other costs. SUMMARY

[0003] The technical problem to be solved by the present application is to overcome the shortcomings of the prior art and provide a preparation method of large-size high-quality titanium alloy rod with good uniformity. The present application utilizes the reasonable matching of forging temperature and cooling speed, utilizes the internal driving force of the material, improves the nucleation rate in the preparation process of titanium alloy rod, and realizes the preparation of large-size titanium alloy rod with uniform organization and performance without investing large-scale forging equipment.

[0004] To achieve the above purpose, the present application adopts the following technical scheme:

[0005] A preparation method of titanium alloy large-size rod, the preparation method comprises the following steps:

[0006] Step 1: heat and keep the titanium alloy ingot at 850℃, keep for 3h after heating, then heat and keep at 140-180℃ above the beta transformation temperature, keep for 3-5h, and use fast forging machine for forging;

[0007] Step 2: heat and keep the blank obtained in step 1 at 900℃, keep for 3h after heating, then heat and keep at 50-100℃ above the beta transformation temperature, keep for 3-4h, and use fast forging machine for forging;

[0008] Step 3: heat and keep the blank obtained in step 2 at 30-60℃ below the beta phase transition point, keep for 6-7h after heating, and use fast forging machine for forging.

[0009] In some embodiments, the preparation method further comprises the following steps:

[0010] Step 4: heat and keep the blank obtained in step 3 at 40-90℃ above the beta phase transition point, keep for 6-7h after heating, use fast forging machine for forging, and then cool the blank in water;

[0011] Step 5: the blank obtained in step 4 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 8-10 hours after heating, and then forged by using a quick forging machine.

[0012] In some embodiments, the preparation method further comprises the following steps:

[0013] Step 6: the blank obtained in step 5 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 5-8 hours after heating, and then forged by using a quick forging machine, and the diagonal elongation is used.

[0014] Step 7: the blank obtained in step 6 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 5-8 hours after heating, and then forged by using a quick forging machine.

[0015] In the present application, the diagonal elongation is performed according to the schematic diagram of the cross section of the rod blank, and specifically, the corners A, B, C and D of the original rod blank are changed to the midlines of the side surfaces of the rod blank, and A, B, C and D are the corners of the original rod blank, and a, b, c and d are the corners of the new rod blank.

[0016]

[0017] In some embodiments, the preparation method further comprises the following steps:

[0018] Step 8: the blank obtained in step 7 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 5-8 hours after heating, and then forged by using a quick forging machine, and the diagonal elongation is used.

[0019] In some embodiments, the preparation method further comprises the following steps:

[0020] Step 9: the blank obtained in step 8 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 5-8 hours after heating, and then forged by using a quick forging machine.

[0021] Step 10: the blank obtained in step 9 is heated and kept at 20-80 DEG C below the beta transus point, and kept for 5-8 hours after heating, and then forged by using a quick forging machine, to obtain the large-size rod material.

[0022] The preparation of the titanium alloy rod material relies on the cumulative deformation below the beta transus point to realize the uniformity of the microstructure and performance, but the single deformation amount is far from enough to achieve the necessary deformation amount, so in actual operation, multiple deformation operations are required, the processing time is long, and the cost is high. The present application realizes the acceleration of the preparation of the titanium alloy rod material through the above-mentioned 10 steps, and can achieve the same quality forging in a shorter time as the prior art.

[0023] In some embodiments, the upsetting deformation amount in step 1 is 40%-50%.

[0024] In some embodiments, the upsetting deformation amount in steps 2-3 is 45% to 55%.

[0025] In some embodiments, the upsetting deformation amount in steps 6-9 is 35% to 45%.

[0026] In some embodiments, the reduction rate in steps 1-10 is 0.5 mm / s to 2.5 mm / s.

[0027] In some embodiments, the final forging temperature in steps 1-10 is not lower than 750 DEG C.

[0028] Compared with the prior art, the present application has the following beneficial effects:

[0029] 1. The present application increases the nucleation rate of the blank by water cooling, improves the nucleation quantity and uniform distribution of the material, and can improve the uniformity of the overall structure and performance of the material. The use of a small press reduces the economic cost, and compared with the preparation of rods by 80MN and 100MN presses, the present application can achieve the same mechanical properties and surpass the uniformity of the structure.

[0030] 2. The present application uses innovative technology to produce large-specification titanium alloy rods, which has low requirements for the preparation equipment, can effectively utilize the existing equipment to realize the preparation of large-specification high-quality titanium alloy rods, and can reduce the equipment capacity requirement from greater than or equal to 60MN to greater than or equal to 20MN, filling the technical gap that the prior art cannot prepare such rods on a 20MN equipment.

[0031] 3. In the prior art, the preparation cost of titanium alloy rods is determined by the number of upsetting and drawing, which is basically linear, and the reduction of the number of upsetting and drawing can be equal to the amount of cost reduction. High-quality, large-size titanium alloy rods generally require 15-17 times of deformation when prepared on a 45MN equipment, while the present application uses innovative technology and only needs 9-13 times of deformation, which can effectively improve the uniformity of the structure and performance of the rods and reduce the number of upsetting and drawing by 20-30%, thereby improving the production efficiency and reducing the production cost.

[0032] 4. Each heating and deformation of the rod has a corresponding loss. Taking a 3000kg ingot as an example, the actual output of the processed ingot after forging is about 2700kg, the weight of the oxidation loss is about 15kg per heating, and the amount of surface damage after each deformation needs to be removed, which is about 15kg. The reduction of the number of upsetting and drawing in the present application can effectively reduce the loss in the preparation process. For example, 4 times of heating and deformation can increase the rod by 120kg, about 4.5%, and 5 times can increase the yield by 5.5% (statistical data, each batch will have fluctuations). BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 a: Edge map of microstructure of TA15 rod of specification.

[0034] Figure 1 b D / 4 site map of microstructure of TA15 rod of specification.

[0035] Figure 1 c: Core map of microstructure of TA15 rod of specification.

[0036] Figure 2 a: Edge map of microstructure of TC4 rod of specification.

[0037] Figure 2 b: D / 4 site map of microstructure of TC4 rod of specification.

[0038] Figure 2 c: Core map of microstructure of TC4 rod of specification.

[0039] Figure 3 a: Edge map of microstructure of TC4 rod of specification.

[0040] Figure 3 b: D / 4 site map of microstructure of TC4 rod of specification.

[0041] Figure 3 c: Core map of microstructure of TC4 rod of specification.

[0042] Figure 4 a: Core map of microstructure of TA15 rod of specification of 300mm.

[0043] Figure 4 b: D / 4 site map of microstructure of TA15 rod of specification of 300mm.

[0044] Figure 4 c: Edge map of microstructure of TA15 rod of specification of 300mm. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0046] Embodiment 1:

[0047] TA15 alloy bar with Φ450mm and length 1200mm is taken as an example, the preparation method steps include:

[0048] Step 1

[0049] TA15 titanium alloy ingot with diameter 650mm is heated at 850℃ and kept for 3h, then heated at 180℃ above the β phase transition point and kept for 3h, and then forged by using a fast forging machine with maximum pressure 20MN, to complete one upsetting and drawing, upsetting deformation is 55%, the pressing speed is 2.5mm / s, and the final forging temperature is 950℃;

[0050] Step 2

[0051] The blank obtained in step 1 is heated at 900℃ and kept for 3h, then heated at 100℃ above the β phase transition point and kept for 3h, and then forged by using a fast forging machine, to complete one upsetting and drawing, upsetting deformation is 50%, the pressing speed is 2.5mm / s, and the final forging temperature is 800℃;

[0052] Step 3

[0053] The blank obtained in step 2 is heated at 50℃ below the β phase transition point and kept for 7h, and then forged by using a fast forging machine, to complete one upsetting and drawing, upsetting deformation is 50%, the pressing speed is 1.5mm / s, and the final forging temperature is 800℃;

[0054] Step 4

[0055] The blank obtained in step 3 is heated at 90℃ above the β phase transition point and kept for 6h, and then forged by using a fast forging machine, to complete one upsetting quickly, upsetting deformation is 010%, and then the blank is cooled by water;

[0056] Step 5

[0057] The blank obtained in step 4 is heated at 70℃ below the β phase transition point and kept for 8h, and then forged by using a fast forging machine, to complete one drawing, and the final forging temperature is 750℃;

[0058] Step 6

[0059] The blank obtained in step 5 is heated at 70℃ below the β phase transition point and kept for 5h, and then forged by using a fast forging machine, to complete one upsetting and drawing, upsetting deformation is 45%, the pressing speed is 1.5mm / s, the drawing adopts "diagonal drawing", and the final forging temperature is 750℃;

[0060] Step 7

[0061] The blank obtained in step 6 is heated and kept at 70 DEG C below the beta transus point for 5 hours, and then forged by using a quick forging machine, to complete two upsetting and drawing, the upsetting deformation is 40%, the pressing speed is 1.5 mm / s, the final forging temperature is 750 DEG C;

[0062] Step 8

[0063] The blank obtained in step 7 is heated and kept at 80 DEG C below the beta transus point for 5 hours, and then forged by using a quick forging machine, to complete one upsetting and drawing, the upsetting deformation is 40%, the pressing speed is 1.5 mm / s, the drawing is diagonal drawing, and the final forging temperature is 750 DEG C;

[0064] Step 9

[0065] The blank obtained in step 8 is heated and kept at 80 DEG C below the beta transus point for 5 hours, and then forged by using a quick forging machine, to complete two upsetting and drawing, the upsetting deformation is 35% each time, the pressing speed is 2 mm / s, and the final forging temperature is 750 DEG C;

[0066] Step 10

[0067] The blank obtained in step 9 is heated and kept at 60 DEG C below the beta transus point for 5 hours, and then forged by using a quick forging machine, the upsetting deformation is 40%, and a Φ450 mm length 1200 mm large-scale rod is obtained.

[0068] By using the method, a Φ450 mm TA15 rod is prepared by 13 times of deformation. The microstructure is shown in Figure 1 After solid solution and aging heat treatment, the mechanical properties are tested according to GB / T 228, and are shown in Table 1. The results show that the method can realize preparation of the Φ450 mm large-scale TA15 rod with uniform microstructure and excellent performance by using a 20 MN free forging press.

[0069] Table 1: Mechanical properties of Φ450 mm TA15 rod

[0070]

[0071]

[0072] Example 2:

[0073] For example, the preparation method steps for preparing a Φ300 mm, length 2000 mm TC4 alloy rod include:

[0074] Step 1

[0075] A TC4 titanium alloy ingot with a diameter of 650 mm is heated at 850 °C for 3 h, then heated at 180 °C above the β phase transition point for 4 h, and then forged by using a fast forging machine to complete one upsetting and drawing, the upsetting deformation is 50%, the pressing speed is 2.5 mm / s, and the final forging temperature is 900 °C;

[0076] Step 2

[0077] The blank obtained in step 1 is heated at 900 °C for 3 h, then heated at 50 °C above the β phase transition point for 4 h, and then forged by using a fast forging machine to complete one upsetting and drawing, the upsetting deformation is 50%, the pressing speed is 2.5 mm / s, and the final forging temperature is not lower than 850 °C;

[0078] Step 3

[0079] The blank obtained in step 2 is heated at 60 °C below the β phase transition point for 6 h, and then forged by using a fast forging machine to complete one upsetting and drawing, the upsetting deformation is 50%, the pressing speed is 2 mm / s, and the final forging temperature is 800 °C;

[0080] Step 4

[0081] The blank obtained in step 3 is heated at 40 °C above the β phase transition point for 6 h, and then forged by using a fast forging machine to complete one upsetting, the upsetting deformation is 10%, and then the blank is cooled by water;

[0082] Step 5

[0083] The blank obtained in step 4 is heated at 60 °C below the β phase transition point for 8 h, and then forged by using a fast forging machine to complete one drawing, and the final forging temperature is 750 °C;

[0084] Step 6

[0085] The blank obtained in step 5 is heated at 60 °C below the β phase transition point for 6 h, and then forged by using a fast forging machine to complete one upsetting and drawing, the upsetting deformation is 45%, the pressing speed is 2.5 mm / s, the drawing is performed by using “diagonal drawing”, and the final forging temperature is 750 °C;

[0086] Step 7

[0087] The blank obtained in step 6 is heated at 80 °C below the β phase transition point for 5 h, and then forged by using a fast forging machine to complete two upsets and drawings, the upsetting deformation is 40% each time, the pressing speed is 2 mm / s, and the final forging temperature is 750 °C;

[0088] Step 8

[0089] The blank obtained in step 7 is heated at 70 DEG C below the beta transus point and kept for 5 hours, and then is forged by using a quick forging machine, with a upsetting deformation of 40%, to obtain a large-size rod of Φ300 mm in length of 2000 mm.

[0090] By using the method, a Φ300 mm TC4 rod is prepared through 9 deformations. The microstructures of different parts are as shown in Figure 2 Table 2, and the mechanical properties tested according to GB / T 228 after common annealing heat treatment are as shown in Table 2. The results show that the Φ300 mm TC4 rod prepared by the method can realize uniform microstructure and excellent performance.

[0091] Table 2: Mechanical properties of Φ300 mm TC4 rod

[0092]

[0093] Example 3:

[0094] Taking preparation of a Φ450 mm TC4 alloy rod with length of 1500 mm as an example, the preparation method steps include:

[0095] Step 1

[0096] The TC4 titanium alloy ingot with diameter of 650 mm is heated at 850 DEG C and kept for 3 hours, then is heated at 180 DEG C above the beta transus point and kept for 4 hours, and then is forged by using a quick forging machine, with one upsetting and drawing, a upsetting deformation of 50%, a pressing rate of 2.5 mm / s, and a final forging temperature of 900 DEG C;

[0097] Step 2

[0098] The blank obtained in step 1 is heated at 900 DEG C and kept for 3 hours, then is heated at 50 DEG C above the beta transus point and kept for 4 hours, and then is forged by using a quick forging machine, with one upsetting and drawing, a upsetting deformation of 50%, a pressing rate of 2.5 mm / s, and a final forging temperature of 850 DEG C;

[0099] Step 3

[0100] The blank obtained in step 2 is heated at 60 DEG C below the beta transus point and kept for 6 hours, and then is forged by using a quick forging machine, with one upsetting and drawing, a upsetting deformation of 50%, a pressing rate of 2 mm / s, and a final forging temperature of 800 DEG C;

[0101] Step 4

[0102] The blank obtained in step 3 is heated at 40 DEG C above the beta transus point and kept for 6 hours, and then is forged by using a quick forging machine, with one fast upsetting, a upsetting deformation of 10%, and then the blank is cooled by water;

[0103] Step 5

[0104] The blank obtained in Step 4 is heated and kept at 60°C below the beta transus point, and after being heated and kept for 8h, forging is performed using a quick forging machine to complete one lengthening, and the final forging temperature is 750°C;

[0105] Step 6

[0106] The blank obtained in Step 5 is heated and kept at 60°C below the beta transus point, and after being heated and kept for 6h, forging is performed using a quick forging machine to complete one upsetting and lengthening, the upsetting deformation is 40%, the pressing speed is 2.5mm / s, the lengthening is performed using “diagonal lengthening”, and the final forging temperature is 750°C;

[0107] Step 7

[0108] The blank obtained in Step 6 is heated and kept at 60°C below the beta transus point, and after being heated and kept for 5h, forging is performed using a quick forging machine to complete two upsetting and lengthenings, the upsetting deformation is 40% each time, the pressing speed is 2mm / s, and the final forging temperature is 750°C;

[0109] Step 8

[0110] The blank obtained in Step 7 is heated and kept at 70°C below the beta transus point, and after being heated and kept for 5h, forging is performed using a quick forging machine to complete one upsetting and lengthening, the upsetting deformation is 40%, the pressing speed is 2mm / s, the lengthening is performed using “diagonal lengthening”, and the final forging temperature is 750°C;

[0111] Step 9

[0112] The blank obtained in Step 8 is heated and kept at 80°C below the beta transus point, and after being heated and kept for 5h, forging is performed using a quick forging machine to complete two upsetting and lengthenings, the upsetting deformation is 35% each time, the pressing speed is 2mm / s, and the final forging temperature is 750°C;

[0113] Step 10

[0114] The blank obtained in Step 9 is heated and kept at 50°C below the beta transus point, and after being heated and kept for 5h, forging is performed using a quick forging machine, the upsetting deformation is 30%, and a Φ450mm length 1500mm large-size rod is obtained.

[0115] Using the method, a Φ450mm TC4 rod is prepared through 13 deformations. The microstructure is as shown in Figure 3 Table 3: Mechanical properties of the Φ450mm TC4 rod

[0116] Table 3: Mechanical properties of the Φ450mm TC4 rod

[0117]

[0118] Example 4:

[0119] Taking the preparation of Φ300mm, 2000mm long TA15 alloy bar as an example, the preparation method steps include:

[0120] Step 1

[0121] The TC4 titanium alloy ingot with a diameter of 650mm is heated and kept at 850℃, and after being kept warm for 3h, it is heated and kept at 180℃ above the β phase transition point, and kept warm for 3h. The fast forging machine is used for forging, and 1 time upsetting and drawing is completed, the upsetting deformation is 55%, the pressing speed is 2.5mm / s, and the final forging temperature is 950℃;

[0122] Step 2

[0123] The blank obtained in step 1 is heated and kept at 900℃, and after being kept warm for 3h, it is heated and kept at 100℃ above the β phase transition point, and kept warm for 4h. The fast forging machine is used for forging, and 1 time upsetting and drawing is completed, the upsetting deformation is 50%, the pressing speed is 2.5mm / s, and the final forging temperature is 900℃;

[0124] Step 3

[0125] The blank obtained in step 2 is heated and kept at 50℃ below the β phase transition point, and after being kept warm for 7h, the fast forging machine is used for forging, and 1 time upsetting and drawing is completed, the upsetting deformation is 50%, the pressing speed is 1.5mm / s, and the final forging temperature is 800℃;

[0126] Step 4

[0127] The blank obtained in step 3 is heated and kept at 90℃ above the β phase transition point, and after being kept warm for 6h, the fast forging machine is used for forging, and 1 time upsetting is quickly completed, the upsetting deformation is 10%, and then the blank is cooled in water;

[0128] Step 5

[0129] The blank obtained in step 4 is heated and kept at 70℃ below the β phase transition point, and after being kept warm for 8h, the fast forging machine is used for forging, and 1 time drawing is completed, and the final forging temperature is 750℃;

[0130] Step 6

[0131] The blank obtained in step 5 is heated and kept at 70℃ below the β phase transition point, and after being kept warm for 58h, the fast forging machine is used for forging, and 1 time upsetting and drawing is completed, the upsetting deformation is 45%, the pressing speed is 1.5mm / s, the drawing adopts "diagonal drawing", and the final forging temperature is 750℃;

[0132] Step 7

[0133] The billet obtained in step 6 is heated and held at 70°C below the β phase transformation point. After reaching the temperature, it is held for 5 hours and then forged using a high-speed forging machine. Two upsetting and drawing processes are completed, with an upsetting deformation of 40% each time, a reduction rate of 1.5 mm / s, and a final forging temperature of 750°C.

[0134] Step 8

[0135] The billet obtained in step 7 is heated and held at 80°C below the β phase transformation point. After reaching the temperature, it is held for 5 hours and then forged using a high-speed forging machine. The upsetting deformation is 30%, resulting in a large-diameter bar with a diameter of 300mm and a length of 2000mm.

[0136] Using this method, TA15 bars with a diameter of 300 mm were prepared through nine deformation processes. Their microstructure is as follows: Figure 4 As shown in the figure, the bar stock forged using this process exhibits minimal microstructure variation from the center to the edge in the tangential direction. For the Φ300mm bar stock, the microstructure variation from the center to the edge is almost negligible. The mechanical properties, tested according to GB / T228 after high-temperature annealing heat treatment, are shown in Table 4. The results demonstrate that this method can achieve the production of large-diameter TA15 bars with uniform microstructure and excellent properties (Φ300mm) using a 20MN free forging press.

[0137] Table 4: Mechanical properties of TA15 bars with a diameter of 300mm

[0138]

[0139] The above description represents a preferred embodiment of the present invention. It can be seen that the present invention enables the preparation of high-quality, large-size titanium alloy bars using small presses such as 20MN with minimal deformation. Compared with publicly available information, the microstructure and properties of the titanium alloy bars prepared by the present invention using a 20MN press are no less than those of bars produced by other technologies using 80MN and 100MN presses, and are superior to those of bars prepared using 45MN presses.

[0140] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method of producing a titanium alloy large-size bar, characterized by, The preparation method comprises the following steps: Step 1: heat and keep the titanium alloy ingot at 850 DEG C, keep for 3 hours after heating, then heat and keep at 140-180 DEG C above the beta phase transition temperature, keep for 3-5 hours, and then forge by using a quick forging machine; Step 2: heat and keep the blank obtained in step 1 at 900 DEG C, keep for 3 hours after heating, then heat and keep at 50-100 DEG C above the beta phase transition temperature, keep for 3-4 hours, and then forge by using a quick forging machine; Step 3: heat and keep the blank obtained in step 2 at 30-60 DEG C below the beta phase transition point, keep for 6-7 hours after heating, and then forge by using a quick forging machine; Step 4: heat and keep the blank obtained in step 3 at 40-90 DEG C above the beta phase transition point, keep for 6-7 hours after heating, and then forge by using a quick forging machine, and then cool the blank in water; Step 5: heat and keep the blank obtained in step 4 at 20-80 DEG C below the beta phase transition point, keep for 8-10 hours after heating, and then forge by using a quick forging machine; Step 6: heat and keep the blank obtained in step 5 at 20-80 DEG C below the beta phase transition point, keep for 5-8 hours after heating, and then forge by using a quick forging machine and adopting diagonal elongation; Step 7: heat and keep the blank obtained in step 6 at 20-80 DEG C below the beta phase transition point, keep for 5-8 hours after heating, and then forge by using a quick forging machine; Step 8: heat and keep the blank obtained in step 7 at 20-80 DEG C below the beta phase transition point, keep for 5-8 hours after heating, and then forge by using a quick forging machine and adopting diagonal elongation; Step 9: heat and keep the blank obtained in step 8 at 20-80 DEG C below the beta phase transition point, keep for 5-8 hours after heating, and then forge by using a quick forging machine; Step 10: heat and keep the blank obtained in step 9 at 20-80 DEG C below the beta phase transition point, keep for 5-8 hours after heating, and then forge by using a quick forging machine, so as to obtain the large-size rod; The titanium alloy ingot is a TA14 titanium alloy ingot or a TA15 titanium alloy ingot.

2. The method of producing titanium alloy large-size bar according to claim 1, characterized in that, The upsetting deformation in step 1 is 40%-50%.

3. The method of producing titanium alloy large-size bar according to claim 2, characterized in that, The upsetting deformation in steps 2-3 is 45%-55%.

4. The method of producing titanium alloy large-size bar according to claim 3, characterized in that, The upsetting deformation in steps 6-9 is 35%-45%.

5. The method of producing titanium alloy large-size bar according to claim 4, characterized in that, The reduction rate in steps 1-10 is 0.5-2.5 mm / s.

6. The method of producing titanium alloy large-size bar according to claim 5, characterized in that, The final forging temperature in steps 1-10 is not lower than 750 DEG C.

Images