Preparation method of large beta forged titanium alloy blisk forging

Abstract

A preparation method of a large beta forged titanium alloy blisk forge piece comprises the process of designing a pre-forged blank, the process of manufacturing a pre-forged die and the process of forging the blisk forge piece, and the pre-forged blank is provided with a concentric annular groove and a boss; the process of forging the blade disc forge piece comprises the steps that a bar blank is heated to 60-80 DEG C below the beta phase transformation point; forging and pressing the bar blank at the deformation rate of 10-30mm / s to obtain a pre-forged blank; the pre-forged blank is subjected to finishing after water cooling; the pre-forged blank is heated to 30-40 DEG C above the beta phase transformation point; forging and pressing the pre-forged blank according to the deformation rate of 0.1-0.5 mm / s to obtain a forged piece; and the forge piece is exposed in air to be cooled. By means of the molded surface structure with the grooves and the bosses, metal originally extending in the single direction flows in a staggered mode in the forging forming process of the large blisk forged piece, so that the grain orientation is changed, the size of a texture macro area is reduced, and the yield of the large blisk forged piece is improved. And the atomic diffusivity in the pre-forging stage is reduced through the modes of low-temperature deformation in the pre-forging blank manufacturing process and water cooling after forging, the effect of inhibiting grain growth is achieved, and the flaw detection index is improved.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, in particular to titanium alloy processing, and in particular to a method for preparing a large-scale beta-forged titanium alloy integral blade disk forging. Background Art

[0002] Titanium alloys are widely used in cutting-edge fields such as aerospace, military industry, etc. due to their high specific strength, good corrosion resistance, non-magnetic properties, good welding properties, as well as superconductivity, hydrogen storage and memory. In the aerospace field in particular, the application of titanium alloy forgings is particularly prominent, and they are usually used to manufacture various key components.

[0003] With the development of a new generation of fighters and large aircraft, in order to reduce the number of parts and the added mass of the connection between parts, avoid stress concentration at the joints of components caused by the connection, thereby improving the safety and reliability of aircraft and their engines, reducing structural weight and increasing service life, large-scale and integrated titanium alloy forgings have become an important research direction. The integral blade is a typical lightweight and efficient structure of the compressor system of advanced aircraft engines. It makes the blades and hub into a whole, with the advantages of light weight and avoiding tenon airflow loss, which can significantly improve the thrust-to-weight ratio and fuel efficiency of the engine.

[0004] β forging is the process of heating and forging titanium alloy billets at a temperature above the β phase transformation point. This forging method can significantly reduce the deformation resistance of the metal, improve process plasticity, and thus reduce costs. At the same time, it can significantly improve creep strength and fracture toughness, and reduce fatigue crack growth rate. It has become an important production method for titanium alloy forgings and is used for forging discs for aircraft engines.

[0005] The existing large-scale β-forged titanium alloy integral blade disc forgings are manufactured by isothermal die forging. First, the rod is heated to 30~40℃ below the β phase transformation point, and then forged into a round pre-forged cake by flat die forging. The pre-forged cake is then heated to 30~40℃ above the β phase transformation point, placed in the die, and forged into a forging. The deformation rate of the two fires is about 1mm / s. Although the existing process scheme can manufacture high-strength and high-toughness products, there is a phenomenon that grains with the same or similar orientation form large-sized texture macro-regions, which leads to technical problems such as large bottom wave changes and high noise levels in ultrasonic testing. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing a large-scale beta-forged titanium alloy integral blade disk forging, which solves the technical problem of the blade disk forging grains forming larger size texture macro-regions in the prior art.

[0007] The method for preparing the large-scale β-forged titanium alloy integral blade disk forging of the present invention comprises a process of designing a pre-forging blank and preparing a pre-forging die and a process of forging the blade disk forging. The process of designing the pre-forging blank and preparing the pre-forging die comprises the following steps: Step D1: the pre-forged blank is designed to be cylindrical in shape, the pre-forged blank is the raw material for manufacturing the forging, the forging is the finished titanium alloy blisk forging, and a plurality of annular grooves are designed at the metal extension position of one end face of the pre-forged blank, and the plurality of grooves are distributed in concentric circles; Step D2: designing a plurality of annular bosses on the other end surface of the pre-forged billet, wherein the number of the bosses is the same as the number of the grooves, and the bosses and the grooves are arranged relative to each other; Step D3: designing and preparing a pre-forging die that is compatible with the pre-forging blank designed in steps D1 to D2; The process of forging a blisk forging comprises the following steps: Step S1: Cut the rod material into a rod blank, heat the rod blank and the pre-forging die described in step D3 to 60-80° C. below the β phase transformation point and keep the temperature constant; Step S2: placing the bar blank processed in step S1 into a pre-forging die, and forging at a deformation rate of 10-30 mm / s to obtain a pre-forging blank; Step S3: taking the pre-forged blank obtained in step S2 out of the pre-forging die, and placing it in water to cool to room temperature; Step S4: cleaning and finishing the pre-forged billet after water cooling in step S3; Step S5: heating the pre-forged billet after finishing in step S4 to 30-40° C. above the β phase transformation point and keeping the temperature, and heating the final forging die to 30-50° C. below the β phase transformation point and keeping the temperature; Step S6: placing the pre-forged blank processed in step S5 into a final forging die, and forging at a deformation rate of 0.1-0.5 mm / s to obtain a forging; Step S7: The forging obtained in step S6 is taken out from the final forging die, and is exposed to air to cool to room temperature.

[0008] Furthermore, in the step D1, the diameter of the pre-forged blank is 2-10 mm smaller than the maximum diameter of the forging, the maximum radial width of the groove and the distance between any two adjacent grooves are both 1 / 10-1 / 20 of the maximum extension distance of the pre-forged blank, the depth of the groove is 40-70% of the height of the pre-forged blank, and a first draft angle of 3-10° is designed on the inner and outer side walls of the groove; In the step D2, the maximum width of the boss is the same as the maximum width of the groove, a second draft angle of 3 to 10° is set on the inner and outer side walls of the boss, and the method for calculating the height of any boss includes a process of calculating the material mass in the first annular cylindrical region of the pre-forged billet and a process of calculating the material mass in the second annular cylindrical region of the forging, The process of calculating the material mass in the first annular cylindrical region of the pre-forged billet is as follows: A first annular cylindrical region is divided in the pre-forged billet, the major diameter of the first annular cylindrical region is equal to the major diameter of the boss, and the minor diameter of the first annular cylindrical region is equal to the minor diameter of the boss. The material mass in the first annular cylindrical region is calculated using the following formula: m1=m 环 -m 槽 =V 环 ×ρ-V 槽 ×ρ =π×(R 2 -r 2 )×H×ρ-(V 槽圆台1 -V 槽圆台2 )×ρ =π×(R 2 -r 2 )×H×ρ-{1 / 3×π×h 槽 ×[R 2 +(Rh 槽 ×tanθ1) 2 +R×(Rh 槽 ×tanθ1)] -1 / 3×π×h 槽 ×[r 2 +(r+h 槽 ×tanθ1) 2 +r×(r+h 槽 ×tanθ1)]}×ρ Where m1 is the material mass in the first annular cylindrical area, m 环 is the material mass of the first annular cylinder region in the annular cylinder of the pre-forged billet, m 槽 is the mass of material removed from the groove, m1, m 环 、m 槽 The unit is kg, H is the height of the pre-forged billet, h 槽 is the depth of the groove, R is the maximum radius of the outer side of the groove, r is the minimum radius of the inner side of the groove, H and h 槽 The units of , R and r are mm, V 槽圆台1 is the volume of the truncated cone formed by the outer surface of the groove, V 槽圆台2 is the volume of the truncated cone formed by the inner surface of the groove, V槽圆台1 、V 槽圆台2 The unit is mm 3 , θ1 is the first draft angle, ρ is the density of titanium alloy, and the unit of ρ is kg / mm 3 ; The process of calculating the material mass in the second annular cylindrical region of the forging is as follows: A second annular cylindrical region is divided on the forging, the major diameter of the second annular cylindrical region is equal to the major diameter of the first annular cylindrical region, and the minor diameter of the second annular cylindrical region is equal to the minor diameter of the first annular cylindrical region, and the material mass of the second annular cylindrical region is calculated; Then, the difference between the material mass of the second annular cylindrical region and the material mass of the corresponding first annular cylindrical region is calculated, and the material mass of the boss is set according to ±5% of the difference. The volume of the boss is calculated based on the material mass and density of the boss. The calculation formula is: V 台 =m 台 / ρ Among them, V 台 is the volume of the boss, V 台 The unit is mm 3 , m 台 is the material mass of the boss, m 台 The unit is kg, ρ is the density of titanium alloy, and the unit of ρ is kg / mm 3 ; Then, the height h of the boss is calculated according to the volume formula of the boss. The calculation formula is: V 台 =V 凸圆台1 -V 凸圆台2 V 台 =1 / 3×π×h×R 2 +(Rh×tanθ2) 2 +R×(Rh×tanθ2)] -1 / 3×π×h×[r 2 +(r+h×tanθ2) 2 + r×(r+h×tanθ2)]; Among them, h is the height of the boss, R is the maximum radius of the outer side of the groove, r is the minimum radius of the inner side of the groove, and the units of h, R, and r are mm. θ2 is the second draft angle, V 台 is the volume of the boss, V 凸圆台1 is the volume of the truncated cone formed by the outer surface of the boss, V 凸圆台2is the volume of the truncated cone formed by the inner side of the boss, V 台 、V 凸圆台1 、V 凸圆台2 The unit is mm 3 ; And the ratio of the height to the width of any boss is less than or equal to 3:1. The calculation formula is: h / L≤3; Wherein, h is the height of the boss, L is the width of the boss, and the units of h and L are mm.

[0009] Furthermore, in step D2, the edges of the groove and boss of the pre-forged blank are provided with transition fillets of R5-10 mm.

[0010] Furthermore, in step D1, a third draft angle of 3 to 5° is set on the side of the pre-forged billet.

[0011] Furthermore, the pre-forging die in step D3 includes a pre-forging upper die and a pre-forging lower die, and the parting position of the pre-forging upper die and the pre-forging lower die is the cylindrical edge of the pre-forging blank.

[0012] Furthermore, in step S2, the load during the pre-forging process is 50-95 MN.

[0013] Furthermore, in step S3, the time for taking the pre-forged billet out of water is ≤1 min, and the water temperature is 20-45°C.

[0014] Furthermore, in step S6, the load during the forming process of the large titanium alloy blisk forging is 60-120 MN.

[0015] The pre-forged blank of the present invention has a profile with concentric circular grooves and bosses, which can control the grain orientation during the forging process to reduce the size of the texture macro-region. The principle is that the grain orientation during the thermal deformation process is mainly determined by the metal flow direction, and a continuous long extension distance in a single direction is prone to cause the phenomenon of concentrated distribution of grains with the same orientation or similar orientation. The concave and convex profile structure causes the metal that originally extends in a single direction to flow in a dislocated manner during the forging process of the large integral blade forging, thereby changing the grain orientation and reducing the size of the texture macro-region.

[0016] The present invention describes a process of manufacturing a pre-forged billet under conditions of low temperature and high deformation rate, and then manufacturing forgings under conditions of high temperature and low deformation rate, which can inhibit the growth of dynamic recrystallization grains, thereby preventing the occurrence of large texture macro-regions caused by large grains. The principle is that when the material undergoes dynamic recrystallization, new grains will be generated. Under long-term high temperature conditions, these grains will continue to grow due to the strong atomic diffusion ability, especially when they are in the β zone, the growth rate is faster. The present invention reduces the atomic diffusion ability at this stage by low-temperature deformation during the manufacturing of the pre-forged billet and water cooling after forging. At the same time, the high deformation rate can effectively shorten the growth time of the grains in the hot state, thereby achieving the effect of inhibiting the growth of recrystallized grains.

[0017] By reducing the size of the texture macro-region, the bottom wave change and noise level in the ultrasonic inspection of large β-forged titanium alloy integral blade disk forgings are finally reduced. The principle is: the detection of bottom wave changes in ultrasonic flaw detection is carried out by detecting the difference in reflected energy in an area, and the generation of noise is mainly due to the scattering and diffraction when it encounters an uneven medium or interface during propagation. When more grains of the same orientation or similar orientation are concentrated, a larger texture macro-region will be formed. The different angles between it and the incident wave will cause differences in reflected energy, and even energy loss and severe attenuation of the bottom wave. This is the main reason for the large bottom wave change; the larger texture macro-region can also be regarded as a large grain. The large grain will increase the scattering of ultrasonic waves, thereby increasing the noise level of the product.

[0018] Compared with the prior art, the present invention has a positive and obvious effect. The present invention designs the profile structure of concentric annular grooves and bosses, so that the metal that originally extends in a single direction during the forging process of the large integral blade disk forging undergoes dislocation flow, thereby changing the grain orientation and reducing the size of the texture macro-region. The atomic diffusion capacity in the pre-forging stage is reduced by low-temperature deformation in the process of manufacturing the pre-forging billet and water cooling after forging. At the same time, the high deformation rate can effectively shorten the growth time of the grains in the hot state, thereby achieving the effect of inhibiting grain growth, reducing the size of the texture macro-region to ≤20μm, thereby reducing the bottom wave change in the ultrasonic flaw detection of the large β-forged titanium alloy integral blade disk forging to 1~1.5dB, and reducing the noise level to ≤5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a top view of the large β-forged titanium alloy integral blisk forging of the present invention.

[0020] Figure 2 It is a cross-sectional view of a large β-forged titanium alloy integral blisk forging of the present invention.

[0021] Figure 3 It is a top view of the pre-forged billet of the present invention.

[0022] Figure 4 It is a cross-sectional view of the pre-forged billet of the present invention.

[0023] Figure 5 It is a cross-sectional view of the pre-forging die of the present invention.

[0024] Figure 6 It is a schematic diagram of calculating the boss height of the present invention.

[0025] Markings in the figure: 1, forging; 101, second annular cylindrical area; 2, pre-forged blank; 201, groove; 202, boss; 203, first draft angle; 204, second draft angle; 205, transition radius; 206, third draft angle; 207, first annular cylindrical area; 3, pre-forging upper die; 4, pre-forging lower die. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited thereto.

[0027] Example 1

[0028] A β-forged titanium alloy integral blade forging has an outer diameter of Φ980mm, a maximum thickness of 315mm, a single piece weight of 360kg, a β phase transition point of 910℃, a bar specification of Φ360mm, and a density of ρ=4.51×10 -6 kg / mm 3 .

[0029] The process of designing pre-forging billets and preparing pre-forging dies includes the following steps: Step D1: Design a cylindrical pre-forging blank 2 with an outer diameter of Φ970mm and a thickness of H=110mm. According to the specifications of the bar blank, the maximum extension distance of the pre-forging is 315mm. According to 1 / 10 of the maximum extension distance, three annular grooves 201 are added at the extension position of the upper end surface of the pre-forging blank 2. The radial width of each groove 201 and the interval between any two adjacent grooves 201 are both 32mm. The specific dimensions of the grooves 201 are: the inner radius r1=196mm and the outer radius R1=228mm of the first groove, the inner radius r2=260mm and the outer radius R2=292mm of the second groove, the inner radius r3=324mm and the outer radius R3=356mm of the third groove, and the depth of the groove 201 is designed to be h according to 60% of the thickness of the pre-forging blank. 槽 =66mm, a first draft angle 203 of θ1=5° is set on the inner and outer walls of the groove 201; Step D2: On the other end face of the pre-forged billet 2, three annular bosses 202 of the same width are added according to the position of the groove 201, and a second draft angle 204 of θ2 = 5° is set on the inner and outer side walls of the bosses, such as Figure 6 As shown, L is the width of the boss 202 and the groove 201. The material mass m1 of the first annular column region 207 of the pre-forged billet 2 is calculated by first calculating the mass m of the annular column where the groove is located. 环 , minus the material mass m of the groove 201 槽 , the material mass m1 of the first annular cylindrical region 207 is obtained; the mass m of the annular cylindrical region where the groove 201 is located is obtained. 环 The calculation method is to calculate the volume V according to the volume formula of the annular cylinder 环 Then multiply it by the density ρ of the material to get m1; the material mass m of the groove 201 part 槽 The calculation method is to calculate the volume V of the truncated cone formed by the outer wall of the groove 201 according to the calculation formula of the truncated cone. 槽圆台1 Then subtract the volume V of the truncated cone formed by the inner wall of the groove 201 槽圆台2 The volume V of the groove 201 is obtained 槽 , the volume V of the groove 201 槽 Multiply by the density ρ of the groove to get the mass m of the groove 201 part 槽 , taking the first annular column area 207 as an example, the calculation process is: m 环 =V 环 ×ρ =π×(R1 2 -r1 2 )×H×ρ =π×(228 2 -196 2 )×110×4.51×10 -6 ≈21.15kg m 槽 =V 槽 ×ρ =(V 槽圆台1 -V 槽圆台2 )×ρ ={1 / 3×π×h 槽 ×[R1 2 +(R1-h 槽 ×tanθ1) 2 +R1×(R1-h 槽 ×tanθ1)] -1 / 3×π×h 槽 ×[r1 2 +(r1+h 槽 ×tanθ1)2 +r1×(r1+h 槽 ×tanθ1)]}×ρ ={1 / 3×π×66×[228 2 +(228-66×tan5°) 2 +228×(228-66×tan5°)] -1 / 3×π×66×[196 2 +(196+66×tan5°) 2 +196×(196+66×tan5°)]}×4.51×10 -6 ≈10.4kg m1=m 环 -m 槽 =21.15-10.4=10.75kg The same method as above is used to calculate the material mass of the other two first annular cylindrical regions 207. The material mass of the three first annular cylindrical regions 207 along the diameter direction from inside to outside is 10.75 kg, 14 kg, and 17.2 kg respectively; Subsequently, the material mass m2 of the second annular cylindrical region 101 of the forging 1 is calculated. From the inside to the outside along the diameter direction, they are 24 kg, 28.9 kg, and 30.6 kg respectively. The difference between the material mass of the second annular cylindrical region 101 and the first annular cylindrical region 207 is calculated, that is, 24-10.75=13.25 kg, 28.9-14=14.9 kg, and 30.6-17.2=13.4 kg. The material mass of the boss 202 is set within the range of ±5% of the difference, which is 12.59~13.91 kg, 14.155~15.645 kg, and 12.73~14.07 kg respectively. The boss mass m 台 Set to 13.1kg, 14.7kg, 13.1kg, according to the boss mass m 台 The volume V of the boss 202 is calculated by using the density ρ 台 , and then take the height h of the boss 202 as an unknown number, according to the volume V of the truncated cone formed by the outer wall of the boss 202 凸圆台1 Subtract the volume V of the truncated cone formed by the inner wall of the boss 202 凸圆台2 Get V 台 Expression, establish equations and solve to get the height of boss 202. Taking the first boss as an example, the calculation process is: m 台 / ρ=(V 凸圆台1 -V 凸圆台2 ) 13.1 / (4.51×10 -6 )={1 / 3×π×h×[R12 +(R1-h×tanθ2) 2 +R1×(R1-h×tanθ2)] -1 / 3×π×h×[r1 2 +(r1+h×tanθ2) 2 +r1×(r1+h×tanθ2)]} 13.1 / (4.51×10 -6 )=1 / 3×π×h×{[228 2 +(228-h×tan5°) 2 +228×(228-h×tan5°)] -[196 2 +(196+h×tan5°) 2 +196×(196+h×tan5°)]} Solving the equation, we get h = 91 mm; The same method as above is used to calculate the heights of the other two bosses 202. Finally, the heights of the three bosses 202 are calculated to be 91 mm, 74 mm, and 50 mm, respectively. Then, the ratio of the height to the width of the boss 202 is calculated based on the width of the boss 202, which is 32 mm. The obtained results are all less than 3. Therefore, the height of the boss 202 is set to 91 mm, 74 mm, and 50 mm. If the ratio is greater than 3, the width of the boss in step D1 is enlarged and the height of the boss is recalculated. Add a transition radius 205 of R10 to the edges of the groove 201 and the boss 202 of the pre-forged billet 2; Step D3: designing and preparing a pre-forging die that matches the pre-forging blank designed in steps D1 to D2, the diameter of the pre-forging upper die 3 and the pre-forging lower die 4 at the parting point in the die cavity is Φ970 mm, and the third draft angle 206 is 3°; The process of forging blisk forgings includes the following steps: Step S1: Cut the titanium alloy bar into a bar blank, heat the bar blank to 850° C. and keep it warm for 5 hours, and at the same time heat the pre-forging die described in step D4 at 850° C. and keep it warm for 10 hours; Step S2: placing the bar into the cavity of the pre-forging die, and completing the manufacturing of the pre-forging blank at a forging load of 60 MN and a deformation rate of 10 mm / s; Step S3: Open the pre-forging die, take out the pre-forging billet 2 and immediately put it into 20° C. water to cool to room temperature.

[0030] Step S4: cleaning and finishing the pre-forged billet 2, specifically cleaning the flash and surface impurities; Step S5: heating the pre-forged billet 2 to 940° C. and keeping the temperature for 2.5 hours, and simultaneously heating the die used in the forming forging process at 870° C. and keeping the temperature for 10 hours; Step S6: placing the pre-forged blank 2 into the cavity of the final forging die, and completing the manufacture of the forging 1 at a forging load of 75 MN and a deformation rate of 0.1 mm / s; Step S7: Take out the forging 1 from the final forging die and expose it to air to cool to room temperature.

[0031] Example 2 A β-forged titanium alloy integral blade forging has an outer diameter of Φ1200mm, a maximum thickness of 276mm, a single piece weight of 300kg, a β phase transition point of 900℃, a bar specification of Φ320mm, and a density of ρ=4.51×10 -6 kg / mm 3 .

[0032] The process of designing pre-forging billets and manufacturing pre-forging dies includes the following steps: Step D1: Design a cylindrical pre-forging blank 2 with an outer diameter of Φ1195 mm and a thickness of H=53 mm. According to the specifications of the bar blank, the maximum extension distance of the pre-forging is 437.5 mm. According to 1 / 15 of the maximum extension distance, five annular grooves 201 are added to the upper end surface of the extension position of the upper end surface of the pre-forging blank 2. The radial width of each groove 201 and the interval between any two adjacent grooves 201 are both 30 mm. The specific dimensions of the grooves 201 are: the inner radius of the first groove r1=237.5 mm, The outer radius R1 = 267.5mm, the inner radius r2 = 297.5mm and the outer radius R2 = 327.5mm of the second groove, the inner radius r3 = 357.5mm and the outer radius R3 = 387.5mm of the third groove, the inner radius r4 = 417.5mm and the outer radius R4 = 447.5mm of the fourth groove, the inner radius r5 = 477.5mm and the outer radius R5 = 507.5mm of the fifth groove, and the depth of groove 201 is designed to be 40% of the thickness of the pre-forged billet as h 槽 =22mm, and a first draft angle 203 of θ1=10° is set on the inner and outer walls of the groove 201; Step D2: On the other end face of the pre-forged billet 2, five annular bosses 202 of the same width are added according to the position of the groove 201, and a second draft angle 204 of θ2 = 10° is set on the inner and outer walls of the bosses. The material mass m1 of the first annular column region 207 of the pre-forged billet 2 is calculated by first calculating the mass m1 of the annular column where the groove is located. 环 , minus the material mass m of the groove 201 槽 , the material mass m1 of the first annular cylindrical region 207 is obtained; the mass m of the annular cylinder where the groove 201 is located is obtained. 环 The calculation method is to calculate the volume V according to the volume formula of the annular cylinder 环Multiply it by the density ρ of the material to get m1; the mass of the material removed from the groove 201 is m 槽 The calculation method is to first calculate the volume V of the truncated cone formed by the outer wall of the groove 201 according to the calculation formula of the truncated cone. 槽圆台1 Then subtract the volume V of the truncated cone formed by the inner wall of the groove 201 槽圆台2 The volume V of the groove 201 is obtained 槽 , the volume V of the groove 201 槽 Multiplying by the density of the groove ρ gives the mass m of material removed by the groove 201 槽 , taking the first annular column area 207 as an example, the calculation process is: m 环 =V 环 ×ρ =π×(R1 2 -r1 2 )×H×ρ =π×(267.5 2 -237.5 2 )×53×4.51×10 -6 ≈11.4kg m 槽 =V 槽 ×ρ =(V 槽圆台1 -V 槽圆台2 )×ρ ={1 / 3×π×h 槽 ×[R1 2 +(R1-h 槽 ×tanθ1) 2 +R1×(R1-h 槽 ×tanθ1)] -1 / 3×π×h 槽 ×[r1 2 +(r1+h 槽 ×tanθ1) 2 +r1×(r1+h 槽 ×tanθ1)]}×ρ ={1 / 3×π×22×[267.5 2 +(267.5-22×tan10°) 2 +267.5×(267.5-22×tan10°)] -1 / 3×π×22×[237.5 2 +(237.5+22×tan10°) 2 +237.5×(237.5+22×tan10°)]}×4.51×10 -6 ≈4.1kg m1=m 环 -m 槽 =11.4-4.1=7.3kg The same method as above is used to calculate the material mass of the other four first annular column regions 207. The material mass of the five first annular column regions 207 is calculated to be 7.3 kg, 9 kg, 10.7 kg, 12.4 kg, and 14.1 kg from the inside to the outside along the diameter direction. Subsequently, the material mass of the second annular cylindrical region 101 of the forging 1 is calculated, and the values ​​are 12.1 kg, 13.8 kg, 15 kg, 15.7 kg, and 16 kg from the inside to the outside along the diameter direction. Subsequently, the difference between the material mass of the second annular cylindrical region 101 and the first annular cylindrical region 207 is calculated, namely, 12.1-7.3=4.8 kg, 13.8-9=4.8 kg, 15-10.7=4.3 kg, 15.7-12.4=3.3 kg, and 16-14.1=1.9 kg. The material mass of the boss 202 is set within the range of ±5% of the difference, and the ranges are: 4.56~5.04 kg, 4.56~5.04 kg, 4.085~4.515 kg, 3.135~3.465 kg, and 1.805~1.995 kg, respectively. The boss mass m 台 Set to 4.8kg, 4.8kg, 4.3kg, 3.3kg, 1.9kg, according to the boss mass m 台 The volume V of the boss 202 is calculated by using the density ρ 台 , and then take the height h of the boss 202 as an unknown number, according to the volume V of the truncated cone formed by the outer wall of the boss 202 凸圆台1 Subtract the volume V of the truncated cone formed by the inner wall of the boss 202 凸圆台2 Get V 台 Expression, establish equations and solve to get the height of boss 202. Taking the first boss as an example, the calculation process is: m 台 / ρ=(V 凸圆台1 -V 凸圆台2 ) 13.1 / (4.51×10 -6 )={1 / 3×π×h×[R1 2 +(R1-h×tanθ2) 2 +R1×(R1-h×tanθ2)] -1 / 3×π×h×[r1 2 +(r1+h×tanθ2) 2 +r1×(r1+h×tanθ2)]} 13.1 / (4.51×10 -6)=1 / 3×π×h×{[267.5 2 +(267.5-h×tan10°) 2 +267.5×(267.5-h×tan10°)] -[237.5 2 +(237.5+h×tan10°) 2 +237.5×(237.5+h×tan10°)]} Solving the equation, we get h = 27 mm; The same method as above is used to calculate the heights of the other four bosses 202. Finally, the heights of the five bosses 202 are calculated to be 27 mm, 21 mm, 15 mm, 10 mm and 5 mm, respectively. Then, the ratio of the height to the width of the boss 202 is calculated based on the width of the boss 202, which is 30 mm. The obtained results are all less than 3. Therefore, the heights of the boss 202 are set to 27 mm, 21 mm, 15 mm, 10 mm and 5 mm. If the ratio is greater than 3, the width of the boss in step D1 is enlarged and the height of the boss is recalculated. Step D3: designing and preparing a pre-forging die that matches the pre-forging blank designed in steps D1 to D2, the diameter of the middle parting point of the pre-forging upper die 3 and the pre-forging lower die 4 is Φ1195 mm, and the third draft angle 206 is 5°; The process of forging blisk forgings includes the following steps: Step S1: Cut the titanium alloy bar into a bar blank, heat the bar blank to 840° C. and keep it warm for 6 hours, and at the same time heat the pre-forging die described in step D4 at 840° C. and keep it warm for 10 hours; Step S2: placing the rod blank into the cavity of the pre-forging die, and completing the manufacturing of the pre-forging blank at a forging load of 90 MN and a deformation rate of 10 mm / s; Step S3: Open the pre-forging die, take out the pre-forging blank 2 and immediately put it into 20°C water to cool to room temperature; Step S4: cleaning and finishing the pre-forged blank 2, specifically cleaning the flash and surface impurities; Step S5: heating the pre-forged billet 2 to 930° C. and keeping the temperature for 2 hours, and simultaneously heating the die used in the forming forging process to 860° C. and keeping the temperature for 10 hours; Step S6: placing the pre-forged blank 2 into the cavity of the terminal die, and completing the manufacture of the forging 1 at a forging load of 115 MN and a deformation rate of 0.1 mm / s; Step S7: Take out the forging 1 from the cavity of the terminal die and expose it to air to cool to room temperature.

[0033] Comparative Example 1 A beta forged titanium alloy integral blade disk forging has an outer diameter of about Φ980mm, a maximum thickness of about 315mm, a single piece weight of about 360kg, a beta phase transition point of 910℃, and a bar specification of Φ340mm. The manufacturing method includes the following steps: Step S1: heating the titanium alloy rod to 880° C. and keeping the temperature for 5 hours, and simultaneously heating the flat die at 880° C. and keeping the temperature for 10 hours; Step S2: placing the bar into a flat die, and completing the manufacture of a pancake-shaped pre-forged blank at a forging load of 45 MN and a deformation rate of 1 mm / s; Step S3: opening the die used for pre-forging, taking out the pre-forged billet and exposing it to air to cool to room temperature; Step S4: cleaning and finishing the pre-forged billet; Step S5: heating the pancake-shaped pre-forged blank to 940° C. and keeping the temperature for 2.5 hours, and at the same time heating the die used in the forming forging process at 870° C. of the titanium alloy material used and keeping the temperature for 10 hours; Step S6: placing the pre-forged blank into the die cavity, and completing the manufacture of the forging at a forging load of 75 MN and a deformation rate of 1 mm / s; Step S7: Open the die, take out the forging and expose it to air to cool to room temperature.

[0034] Comparative Example 2 A β-forged titanium alloy integral blade disk forging has an outer diameter of about Φ1200mm, a maximum thickness of about 276mm, a single piece weight of about 300kg, a β phase transition point of 900℃, and a bar specification of Φ320mm. The manufacturing method includes the following steps: Step S1: heating the titanium alloy rod to 870° C. and keeping the temperature for 4.5 hours, and simultaneously heating the flat die at 870° C. and keeping the temperature for 10 hours; Step S2: placing the bar into a flat die, and completing the manufacture of a pancake-shaped pre-forged blank at a forging load of 68 MN and a deformation rate of 1 mm / s; Step S3: opening the die used for pre-forging, taking out the pre-forged billet and exposing it to air to cool to room temperature; Step S4: cleaning and finishing the pre-forged billet; Step S5: heating the cake-shaped pre-forged blank to 930° C. and keeping the temperature for 2 hours, and at the same time heating the die used in the forming forging process at 870° C. of the titanium alloy material used and keeping the temperature for 10 hours; Step S6: placing the pre-forged blank into the die cavity, and completing the manufacture of the forging at a forging load of 115 MN and a deformation rate of 1 mm / s; Step S7: Open the die, take out the forging and expose it to air to cool to room temperature.

[0035] Table 1 Forging process parameters

[0036] Table 2 Analysis and test results

[0037] From the above-mentioned embodiments and comparative examples combined with Table 1, it can be seen that the weight, size, material β phase transition point and basic process route of the integral blade disks of "Comparative Example 1 and Example 1" and "Comparative Example 2 and Example 2" are exactly the same, but the pre-forging blanks used in Comparative Example 1 and Example 2 are in the shape of a cake, while Examples 1 and Example 2 are cylindrical pre-forging blank structures with concentric annular grooves and bosses; in the process of manufacturing the pre-forging blanks in Comparative Example 1 and Example 2, the heating and insulation temperature of the bar is 30°C below the β phase transition point, the deformation rate is 1mm / s, and the cooling method is air cooling, while in Examples 1 and Example 2, the heating and insulation temperature of the bar is 60°C below the β phase transition point, the deformation rate is 10mm / s, and the cooling method is water cooling.

[0038] After analyzing and testing the forgings manufactured in all comparative examples and embodiments, the forgings manufactured in comparative example 1 have a maximum size of a texture macro-region of about 100 μm, a bottom wave change of about 5 dB, and a measured noise level of 18% to 21% (Φ1.2 flat-bottom hole); the forgings manufactured in comparative example 2 have a maximum size of a texture macro-region of about 120 μm, a bottom wave change of 5 dB to 6 dB, and a measured noise level of 20% to 23% (Φ1.2 flat-bottom hole), while the forgings manufactured in embodiment 1 have a maximum size of a texture macro-region of 10 μm, a bottom wave change of about 1 dB, and a measured noise level of 2% to 3% (Φ1.2 flat-bottom hole); the forgings manufactured in embodiment 2 have a maximum size of a texture macro-region of about 20 μm, a bottom wave change of 1 dB to 1.5 dB, and a measured noise level of 2% to 5% (Φ1.2 flat-bottom hole).

Claims

1. A method for preparing a large β-forged titanium alloy blisk forging, characterized in that: It includes a process of designing a pre-forging blank, preparing a pre-forging die, and a process of forging a blade disk forging. The process of designing the pre-forging blank and preparing the pre-forging die comprises the following steps: Step D1: the pre-forged blank is designed to be cylindrical in shape, the pre-forged blank is the raw material for manufacturing the forging, the forging is the finished titanium alloy blisk forging, and a plurality of annular grooves are designed at the metal extension position of one end face of the pre-forged blank, and the plurality of grooves are distributed in concentric circles; Step D2: designing a plurality of annular bosses on the other end surface of the pre-forged billet, wherein the number of the bosses is the same as the number of the grooves, and the bosses and the grooves are arranged relative to each other; Step D3: designing and preparing a pre-forging die that is compatible with the pre-forging blank designed in steps D1 to D2; The process of forging a blisk forging comprises the following steps: Step S1: Cut the rod material into a rod blank, heat the rod blank and the pre-forging die described in step D3 to 60-80° C. below the β phase transformation point and keep the temperature constant; Step S2: placing the bar blank processed in step S1 into a pre-forging die, and forging at a deformation rate of 10-30 mm / s to obtain a pre-forging blank; Step S3: taking the pre-forged blank obtained in step S2 out of the pre-forging die, and placing it in water to cool to room temperature; Step S4: cleaning and finishing the pre-forged billet after water cooling in step S3; Step S5: heating the pre-forged billet after finishing in step S4 to 30-40° C. above the β phase transformation point and keeping the temperature, and heating the final forging die to 30-50° C. below the β phase transformation point and keeping the temperature; Step S6: placing the pre-forged blank processed in step S5 into a final forging die, and forging at a deformation rate of 0.1-0.5 mm / s to obtain a forging; Step S7: The forging obtained in step S6 is taken out from the final forging die, and is exposed to air to cool to room temperature.

2. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In the step D1, the diameter of the pre-forged blank is 2-10 mm smaller than the maximum diameter of the forging, the maximum radial width of the groove and the distance between any two adjacent grooves are both 1 / 10-1 / 20 of the maximum extension distance of the pre-forged blank, the depth of the groove is 40-70% of the height of the pre-forged blank, and a first draft angle of 3-10° is designed on the inner and outer side walls of the groove; In the step D2, the maximum width of the boss is the same as the maximum width of the groove, a second draft angle of 3 to 10° is set on the inner and outer side walls of the boss, and the method for calculating the height of any boss includes a process of calculating the material mass in the first annular cylindrical region of the pre-forged billet and a process of calculating the material mass in the second annular cylindrical region of the forging, The process of calculating the material mass in the first annular cylindrical region of the pre-forged billet is as follows: A first annular cylindrical region is divided in the pre-forged billet, the major diameter of the first annular cylindrical region is equal to the major diameter of the boss, and the minor diameter of the first annular cylindrical region is equal to the minor diameter of the boss. The material mass in the first annular cylindrical region is calculated using the following formula: m1=m 环 -m 槽 =V 环 ×ρ-V 槽 ×ρ =π×(R 2 -r 2 )×H×ρ-(V 槽圆台1 -V 槽圆台2 )×ρ =π×(R 2 -r 2 )×H×ρ-{1 / 3×π×h 槽 ×[R 2 +(R-h 槽 ×tanθ1) 2 +R×(R-h 槽 ×tanθ1)] -1 / 3×π×h 槽 ×[r 2 +(r+h 槽 ×tanθ1) 2 +r×(r+h 槽 ×tanθ1)]}×ρ Where m1 is the material mass in the first annular cylindrical area, m 环 is the material mass of the first annular cylinder region in the annular cylinder of the pre-forged billet, m 槽 is the mass of material removed from the groove, m1, m 环 、m 槽 The unit is kg, H is the height of the pre-forged billet, h 槽 is the depth of the groove, R is the maximum radius of the outer side of the groove, r is the minimum radius of the inner side of the groove, H and h 槽 The units of , R and r are mm, V 槽圆台1 is the volume of the truncated cone formed by the outer wall of the groove, V 槽圆台2 is the volume of the truncated cone formed by the inner wall of the groove, V 槽圆台1 、V 槽圆台2 The unit is mm 3 , θ1 is the first draft angle, ρ is the density of titanium alloy, and the unit of ρ is kg / mm 3 ; The process of calculating the material mass in the second annular cylindrical region of the forging is as follows: A second annular cylindrical region is divided on the forging, the major diameter of the second annular cylindrical region is equal to the major diameter of the first annular cylindrical region, and the minor diameter of the second annular cylindrical region is equal to the minor diameter of the first annular cylindrical region, and the material mass of the second annular cylindrical region is calculated; Then, the difference between the material mass of the second annular cylindrical region and the material mass of the corresponding first annular cylindrical region is calculated, and the material mass of the boss is set according to ±5% of the difference. The volume of the boss is calculated based on the material mass and density of the boss. The calculation formula is: V 台 =m 台 / r Among them, V 台 is the volume of the boss, V 台 The unit is mm 3 , m 台 is the material mass of the boss, m 台 The unit is kg, ρ is the density of titanium alloy, and the unit of ρ is kg / mm 3 ; Then, the height h of the boss is calculated according to the volume formula of the boss. The calculation formula is: V 台 =V 凸圆台1 -V 凸圆台2 V 台 =1 / 3×π×h×[R 2 +(R-h×tanθ2) 2 +R×(R-h×tanθ2)] -1 / 3×π×h×[r 2 +(r+h×tanθ2) 2 + r×(r+h×tanθ2)]; Among them, h is the height of the boss, R is the maximum radius of the outer side of the groove, r is the minimum radius of the inner side of the groove, and the units of h, R, and r are mm. θ2 is the second draft angle, V 台 is the volume of the boss, V 凸圆台1 is the volume of the truncated cone formed by the outer wall of the boss, V 凸圆台2 is the volume of the truncated cone formed by the inner wall of the boss, V 台 、V 凸圆台1 、V 凸圆台2 The unit is mm 3 ; And the ratio of the height to the width of any boss is less than or equal to 3:

1. The calculation formula is: h / L≤3; Wherein, h is the height of the boss, L is the width of the boss, and the units of h and L are mm.

3. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In the step D2, the edges of the groove and the boss of the pre-forged blank are provided with transition fillets of R5-10 mm.

4. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In the step D1, a third draft angle of 3 to 5° is set on the side of the pre-forged billet.

5. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: The pre-forging die in step D3 comprises a pre-forging upper die and a pre-forging lower die, and the parting position of the pre-forging upper die and the pre-forging lower die is the cylindrical edge of the pre-forging blank.

6. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In the step S2, the load during the pre-forging process is 50-95 MN.

7. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In step S3, the time for taking the pre-forged billet out of the water is ≤1 min, and the water temperature is 20-45°C.

8. The method for preparing a large β-forged titanium alloy blisk forging according to claim 1, characterized in that: In step S6, the load during the forming process of the large titanium alloy blisk forging is 60-120 MN.

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