Forging method of TC9 titanium alloy large-specification bar

Abstract

According to the forging method for the TC9 titanium alloy large-specification bar, even deformation of forging of the bar with the diameter phi ranging from 130 mm to 200 mm is achieved, and the good mechanical property is obtained. A cast ingot is subjected to upsetting and drawing forging through a high-speed forging machine in a beta single-phase region and then subjected to combined forging through the high-speed forging machine and a precision forging machine in an alpha + beta two-phase region, and by controlling the heating temperature, the heating number, the upsetting / drawing rolling reduction of the high-speed forging machine, the diameter reducing amount of the precision forging machine, the finish forging temperature and the deformation amount, it can be guaranteed that a bar deforms evenly, and good mechanical performance is obtained. The method has the following advantages that the process is simple, wherein a cast ingot is subjected to upsetting and drawing forging in a beta single-phase region by adopting a high-speed forging machine, and then is subjected to combined forging in an alpha + beta two-phase region by adopting the high-speed forging machine and a precision forging machine; by controlling the heating temperature, the heating number, the upsetting / drawing reduction of the fast forging machine, the reducing amount of the precision forging machine, the finish forging temperature and the deformation amount, uniform deformation of the bar is guaranteed, good mechanical performance is obtained, and the method is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention belongs to a method for manufacturing alloy bars, and in particular relates to a method for forging large-size TC9 titanium alloy bars. Background Art

[0002] The high-temperature titanium alloy successfully developed by the Soviet Union in 1958 is BT9 alloy, the main components are: titanium: 6.5%, aluminum: 3.5%, molybdenum: 2.5%, tin: 0.3%, silicon, mainly used to make parts that work for a long time at 500℃, such as compressor disks and blades on aircraft engines; the Soviet Union replaced the tin element in BT9 alloy with zirconium in 1966. my country began to develop TC9 titanium alloy in 1966, which is the same alloy as the Soviet high-temperature titanium alloy BT9, with exactly the same nominal chemical composition. TC9 belongs to the α+β type heat-resistant titanium alloy, containing α-stabilizing element aluminum, neutral element tin, isomorphous β-stabilizing element molybdenum and eutectoid β-stabilizing element silicon; later, my country also replaced the tin element in TC9 alloy with zirconium, evolving into the current TC11 alloy. The main products of TC9 titanium alloy are cakes and bars. Relevant data show that the maximum bar size Φ65mm is difficult to meet the application requirements of large-size bars. Summary of the invention

[0003] The invention discloses a forging method for a large-size TC9 titanium alloy bar, which can achieve uniform forging deformation of the bar with a diameter of Φ130 mm to Φ200 mm and obtain good mechanical properties.

[0004] The present invention adopts the following forging process:

[0005] ⑴Φ508mm / Φ610mm ingot in T β Above 140℃~170℃(T β The ingot is heated at a temperature of 400°C (600°F) and a 3150T fast forging machine is used to complete 2-3 times of upsetting and drawing forging. The downstroke of each upsetting is 280mm-300mm, the downstroke of the drawing pass is 60mm-70mm, the final forging temperature is not less than 900°C, and the cumulative deformation is not less than 90%, to obtain an octagonal forging blank.

[0006] ⑵ Octagonal forging billet in T β The above heating is performed at 20℃~40℃, and 3150T fast forging machine is used to complete 1~2 times of upsetting and drawing forging. The downstroke of each upsetting is 250mm~270mm, and the downstroke of the drawing pass is 50mm~60mm. The final forging temperature is not lower than 850℃, and the cumulative deformation is not less than 80%, so as to obtain a square forging billet.

[0007] ⑶ The square forging billet is cooled to room temperature and then surface ground. βThe forging process is heated at 30-50°C, and a 3150T fast forging machine is used to complete one-pass drawing forging, with a pass reduction of 40mm-50mm and a final forging temperature of not less than 800°C to obtain an octagonal forging billet.

[0008] ⑷ Octagonal forging billet in T β Heat at 30℃~50℃ below, use 1800T precision forging machine for 1 fire forging to finished product, the pass reduction is 20mm~40mm, the last pass is 5mm~10mm for surface shaping, the feed speed is 2m / min~4m / min, and the final forging temperature is not less than 750℃.

[0009] ⑸ The cumulative forging deformation in steps ⑶ and ⑷ is not less than 100%.

[0010] The invention points:

[0011] The ingot is forged by upsetting and drawing with a fast forging machine in the β single-phase region, and then forged by a fast forging machine + a fine forging machine in the α+β two-phase region. By controlling the heating temperature, the number of fires, the upsetting / drawing reduction of the fast forging machine, the diameter reduction of the fine forging machine, the final forging temperature and the deformation, the uniform deformation of the bar can be ensured to obtain good mechanical properties.

[0012] The present invention has the following advantages:

[0013] The process is simple: the ingot is forged by upsetting and drawing with a fast forging machine in the β single-phase region, and then forged by a fast forging machine + a fine forging machine in the α+β two-phase region; by controlling the heating temperature, the number of fires, the upsetting / drawing reduction of the fast forging machine, the diameter reduction of the fine forging machine, the final forging temperature and the deformation, the uniform deformation of the bar is ensured, and good mechanical properties are obtained, which is suitable for large-scale industrial production.

[0014] Mechanical properties: room temperature tensile strength (R m ) is not less than 1100MPa, yield strength (R p0.2 ) is not less than 1000MPa, the elongation (A) is not less than 12%, and the cross-sectional shrinkage (Z) is not less than 30%. DETAILED DESCRIPTION

[0015] Example 1

[0016] Φ165mm finished product.

[0017] ⑴Φ508mm ingot at 1150℃(T β The forging process was heated at 1010°C and a 3150T fast forging machine was used to complete three upsetting and drawing forgings. The downstroke for each upsetting was 280mm, the downstroke for the drawing was 60mm-70mm, the final forging temperature was 946°C, the cumulative deformation was 138%, and a Φ460mm octagonal forging blank was obtained.

[0018] (2) The Φ460mm octagonal forging billet is heated at 1040℃ and 3150T fast forging machine is used to complete 2-pass upsetting and drawing forging. The downstroke for each upsetting is 250mm, the downstroke for the drawing pass is 50mm-60mm, the final forging temperature is 880℃, the cumulative deformation is 83%, and a 400mm square forging billet is obtained.

[0019] ⑶ The 400mm square forging billet is cooled to room temperature for surface grinding, then heated at 980℃, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40mm-50mm and a final forging temperature of 825℃ to obtain a Φ300mm octagonal forging billet.

[0020] (4) The Φ300mm octagonal forging billet is heated at 960℃ and forged to Φ165mm finished product by 1800T precision forging machine in one pass. The diameter reduction is 20mm~40mm. The last pass is 5mm~10mm for surface shaping. The feed speed is 2m / min~4m / min and the final forging temperature is 784℃.

[0021] ⑸ Steps ⑶ and ⑷ forging cumulative forging deformation is 119%.

[0022] D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1159MPa, and the yield strength (R p0.2 ) is 1048MPa, the elongation (A) is 18.0%, and the cross-sectional shrinkage (Z) is 38%.

[0023] Example 2

[0024] Φ130mm finished product.

[0025] ⑴Φ610mm ingot at 1170℃(T β The forging process was heated at 1000°C and a 3150T fast forging machine was used to complete two upsetting and drawing forgings. The downstroke for each upsetting was 300mm, the downstroke for the drawing was 60mm-70mm, the final forging temperature was 954°C, the cumulative deformation was 102%, and a Φ560mm octagonal forging blank was obtained.

[0026] (2) The Φ560mm octagonal forging billet is heated at 1030℃ and a 3150T fast forging machine is used to complete one-pass upsetting and drawing forging. The upsetting reduction is 270mm, the drawing reduction is 50mm-60mm, the final forging temperature is 870℃, the cumulative deformation is 85%, and a 350mm square forging billet is obtained.

[0027] (3) The 350mm square forging billet is cooled to room temperature for surface grinding, and then heated at 970°C, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40mm to 50mm and a final forging temperature of 836°C to obtain a Φ280mm octagonal forging billet.

[0028] (4) The Φ280mm octagonal forging billet is heated at 950℃ and forged to Φ130mm finished product by 1800T precision forging machine. The diameter reduction is 20mm~40mm. The last pass is 5mm~10mm for surface shaping. The feed speed is 2m / min~4m / min and the final forging temperature is 775℃.

[0029] ⑸ Steps ⑶ and ⑷ The cumulative forging deformation is 124%.

[0030] D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1177MPa, and the yield strength (R p0.2 ) is 1083MPa, the elongation (A) is 19.5%, and the cross-sectional shrinkage (Z) is 40%.

[0031] Example 3

[0032] Φ200mm finished product.

[0033] ⑴Φ610mm ingot at 1180℃(T β The forging process was heated at 1020°C and a 3150T fast forging machine was used to complete three upsetting and drawing forgings. The downstroke for each upsetting was 300mm, the downstroke for the drawing was 60mm-70mm, the final forging temperature was 962°C, the cumulative deformation was 150%, and a Φ560mm octagonal forging blank was obtained.

[0034] (2) The Φ560mm octagonal forging billet is heated at 1050℃ and 3150T fast forging machine is used to complete 2-pass upsetting and drawing forging. The downstroke for each upsetting is 250mm, the downstroke for the drawing pass is 50mm-60mm, the final forging temperature is 878℃, the cumulative deformation is 89%, and a 480mm square forging billet is obtained.

[0035] ⑶ The 480mm square forging billet is cooled to room temperature for surface grinding, then heated at 990℃, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40mm-50mm and a final forging temperature of 830℃ to obtain a Φ360mm octagonal forging billet.

[0036] (4) The Φ360mm octagonal forging billet is heated at 970℃ and forged to Φ200mm finished product by 1 pass of 1800T precision forging machine. The diameter reduction is 20mm~40mm per pass. The last pass is 5mm~10mm for surface shaping. The feed speed is 2m / min~4m / min and the final forging temperature is 780℃.

[0037] ⑸ Steps ⑶ and ⑷ The cumulative forging deformation is 121%.

[0038] D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1192MPa, and the yield strength (R p0.2) is 1089MPa, the elongation (A) is 17.0%, and the cross-sectional shrinkage (Z) is 37%.

Claims

1. A forging method for large-size TC9 titanium alloy bars, characterized in that: The forging method: ⑴Φ508mm / Φ610mm ingot in T β Above 140℃~170℃(T β The ingot is heated to a temperature of 10000 ℃ (phase transformation point), and a 3150T fast forging machine is used to complete 2-3 times of upsetting and drawing forging, with each upsetting reduction of 280mm-300mm, and the drawing reduction of 60mm-70mm. The final forging temperature is not less than 900℃, and the cumulative deformation is not less than 90%, to obtain an octagonal forging blank; ⑵ Octagonal forging billet in T β The above heating is performed at 20℃~40℃, and 3150T fast forging machine is used to complete 1~2 times of upsetting and drawing forging, each upsetting reduction is 250mm~270mm, and the drawing reduction is 50mm~60mm. The final forging temperature is not less than 850℃, and the cumulative deformation is not less than 80%, to obtain a square forging billet; ⑶ The square forging blank is cooled to room temperature and then surface ground. β After heating at 30℃~50℃, 3150T fast forging machine is used to complete one-pass drawing forging, with a pass reduction of 40mm~50mm and a final forging temperature of not less than 800℃ to obtain an octagonal forging billet; ⑷ Octagonal forging billet in T β Heat at 30℃~50℃, use 1800T precision forging machine to forge to finished product, the pass diameter reduction is 20mm~40mm, the last pass is 5mm~10mm for surface shaping, the feed speed is 2m / min~4m / min, and the final forging temperature is not less than 750℃; ⑸ The cumulative forging deformation in steps ⑶ and ⑷ is not less than 100%.

2. The forging method of a large-size TC9 titanium alloy bar according to claim 1 is characterized in that: Φ165mm finished product forging method: ⑴Φ508mm ingot at 1150℃(T β The forging process was heated to 1010°C, and a 3150T fast forging machine was used to complete three upsetting and drawing forgings, with each upsetting reduction of 280mm, the drawing reduction of 60mm-70mm, the final forging temperature of 946°C, and the cumulative deformation of 138%, to obtain a Φ460mm octagonal forging blank; (2) The Φ460mm octagonal forging billet is heated at 1040℃ and 3150T fast forging machine is used to complete two-pass upsetting and drawing forging. The downstroke of each upsetting is 250mm, the downstroke of each drawing pass is 50mm-60mm, the final forging temperature is 880℃, the cumulative deformation is 83%, and a 400mm square forging billet is obtained; (3) The 400mm square forging billet is cooled to room temperature for surface grinding, and then heated at 980°C, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40mm-50mm and a final forging temperature of 825°C to obtain a Φ300mm octagonal forging billet; (4) Φ300mm octagonal forging billet is heated at 960℃, and forged to Φ165mm finished product by 1800T precision forging machine, with pass diameter reduction of 20mm~40mm, and the last pass is 5mm~10mm for surface shaping, feed speed of 2m / min~4m / min, and final forging temperature of 784℃; ⑸ Steps ⑶ and ⑷ forging cumulative forging deformation is 119%. ⑹D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1159MPa, and the yield strength (R p0.2 ) is 1048MPa, the elongation (A) is 18.0%, and the cross-sectional shrinkage (Z) is 38%.

3. The forging method of a large-size TC9 titanium alloy bar according to claim 1 is characterized in that: Φ165mm finished product forging method: ⑴Φ610mm ingot at 1170℃(T β The forging process is carried out by heating the forging machine at 1000°C for 2 times, and the forging process is carried out by using a 3150T fast forging machine. The forging process is performed by 300mm for each upsetting process, 60mm to 70mm for each drawing process, the final forging temperature is 954°C, and the cumulative deformation is 102%, so as to obtain a Φ560mm octagonal forging blank. (2) The Φ560mm octagonal forging billet is heated at 1030℃ and a 3150T fast forging machine is used to complete one-pass upsetting and drawing forging, with a roughing reduction of 270mm, a long drawing reduction of 50mm-60mm, a final forging temperature of 870℃, and a cumulative deformation of 85%, to obtain a 350mm square forging billet; (3) The 350mm square forging billet is cooled to room temperature for surface grinding, and then heated at 970°C, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40mm-50mm and a final forging temperature of 836°C to obtain a Φ280mm octagonal forging billet; (4) Φ280mm octagonal forging billet is heated at 950℃, and forged to Φ130mm finished product by 1800T fine forging machine, with pass diameter reduction of 20mm~40mm, and the last pass is 5mm~10mm for surface shaping, feed speed of 2m / min~4m / min, and final forging temperature of 775℃; (5) The cumulative forging deformation of steps (3) and (4) is 124%; ⑹D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1177MPa, and the yield strength (R p0.2 ) is 1083MPa, the elongation (A) is 19.5%, and the cross-sectional shrinkage (Z) is 40%.

4. The forging method of a large-size TC9 titanium alloy bar according to claim 1 is characterized in that: Φ200mm finished product forging method: ⑴Φ610mm ingot at 1180℃(T β The forging process is carried out by heating the forging process at 1020°C, and a 3150T fast forging machine is used to complete three times of upsetting and drawing forging, with each upsetting reduction of 300mm, the drawing reduction of 60mm-70mm, the final forging temperature of 962°C, and the cumulative deformation of 150%, to obtain a Φ560mm octagonal forging blank; (2) The Φ560mm octagonal forging billet is heated at 1050℃ and 3150T fast forging machine is used to complete two-pass upsetting and drawing forging. The downstroke of each upsetting is 250mm, the downstroke of each drawing pass is 50mm-60mm, the final forging temperature is 878℃, the cumulative deformation is 89%, and a 480mm square forging billet is obtained; (3) The 480 mm square forging billet is cooled to room temperature for surface grinding, and then heated at 990°C, and a 3150T fast forging machine is used to complete the first fire drawing forging, with a pass reduction of 40 mm to 50 mm and a final forging temperature of 830°C to obtain a Φ360 mm octagonal forging billet; (4) Φ360mm octagonal forging billet is heated at 970℃, and forged to Φ200mm finished product by 1800T fine forging machine, with pass diameter reduction of 20mm~40mm, and the last pass is 5mm~10mm for surface shaping, feed speed of 2m / min~4m / min, and final forging temperature of 780℃; (5) The cumulative forging deformation of steps (3) and (4) is 121%; ⑹D / 4 chord direction, room temperature mechanical properties: tensile strength (R m ) is 1192MPa, and the yield strength (R p0.2 ) is 1089MPa, the elongation (A) is 17.0%, and the cross-sectional shrinkage (Z) is 37%.