A forging process for thin-walled titanium alloy disc-shaped parts and a die therefor

Abstract

The application discloses a kind of thin-walled titanium alloy disc-shaped piece forging process and its mould, process includes the following steps: step one: breakdown forging, two times of fire forging is carried out to raw material bar, first time is upset, second time is punched;Step two: ring rolling, after breakdown, the forged piece is heated to below 35℃-40℃ of phase transition point, then ring rolling is carried out;Step three: die forging, after ring rolling, the forged piece is heated again to below 35℃-40℃ of phase transition point, then, blank is accurately placed in special forging die, then, blank is placed in mould cavity along the shape of cavity, first hammer light knock is positioned, then, using gasket control under pressure amount is 10±1mm and carries out preliminary forging, finally, using 2mm gasket control under pressure amount and carries out full load forging, ensure that one time is completed die forging.Step four: heat treatment, after die forging, the forged piece is immediately sent to heat treatment furnace, then, air cooling is used to carry out rapid cooling.The application realizes the efficient, low-loss production of thin-walled titanium alloy disc-shaped piece by optimizing forging process, accurately controlling deformation and temperature parameters, combined with special forging die.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal processing, and particularly relates to a forging process and die for a thin-walled titanium alloy disc-shaped piece. BACKGROUND

[0002] The thin-walled titanium alloy disc-shaped piece is widely used in many fields such as military products and civilian products due to excellent mechanical properties and wide application prospects. However, the traditional free forging process has many deficiencies when producing such products, such as serious raw material loss, multiple forging to avoid overburning, long production cycle and high cost. Therefore, it is of great significance to develop a new forging process and its matching die for improving production efficiency and reducing production cost. SUMMARY

[0003] To solve the above problems, the present application provides a forging process and die for a thin-walled titanium alloy disc-shaped piece, which realizes efficient and low-loss production of the thin-walled titanium alloy disc-shaped piece by optimizing the forging process, accurately controlling the deformation amount and temperature parameters, and combining the specially-made forging die.

[0004] TECHNICAL SCHEME

[0005] A forging process for a thin-walled titanium alloy disc-shaped piece, comprising the following steps:

[0006] Step one: cogging forging (upsetting + piercing)

[0007] The raw material bar is forged twice, the first time is upsetting, and the second time is piercing; the heating temperature of each fire is controlled below 35-40 DEG C of the phase transition point of titanium alloy, and the heating holding time is 120-240 minutes; the deformation amount of each fire is controlled below 20% during upsetting forging, and the uniform speed is pressed by the hammer, and the pressing speed is controlled at 5-15 mm / s; the punch is needed for rounding treatment after piercing, and the pressing amount is not more than 20 mm each time, the uniform speed is pressed, and the pressing speed is less than 10 mm / s, so as to eliminate the large R angle and ensure that the piercing and rounding are completed in one fire.

[0008] Step two: ring rolling

[0009] The forged piece after cogging is heated to below 35-40 DEG C of the phase transition point, the heating holding time is 50-170 minutes, and then ring rolling is carried out, and the deformation amount of each pass is strictly controlled to ensure that the deformation amount is less than 20%.

[0010] Step three: die forging

[0011] The forged piece after ring rolling is heated again to 35-40 DEG C below the phase transition point, and the heating and holding time is 48-138 minutes; then, the blank is accurately placed in a specially designed forging die, the die is composed of upper and lower dies, and because the forging die is annular, an inner resistance platform is designed, the height of the resistance platform is 3mm, the inner side slope angle is 155 DEG, and the outer side slope angle is 97 DEG, so as to prevent the metal from flowing to the inside; during die forging, first, compressed air is used to blow away the dirt in the die cavity, and the die lubricant is uniformly sprayed; then, the blank is placed in the die cavity along the shape of the cavity, the first hammer is lightly hit to position, then a 10mm pad is used to control the under-pressure amount to 10+ / -1mm for preliminary forging, finally, a 2mm pad is used to control the under-pressure amount for full-load forging, so as to ensure that the die forging is completed in one heating.

[0012] Step four: heat treatment

[0013] The forged piece after die forging is immediately sent to a heat treatment furnace, heated to 840 DEG C and held for 90-100 minutes, and then rapidly cooled by air cooling, at least 8 fans are provided, and the fan rotating speed is set to 1200r / min.

[0014] Forging die design:

[0015] A die for forging a thin-walled titanium alloy disc-shaped piece, comprising upper and lower dies, and an inner resistance platform is designed in the upper die or the lower die, the height of the inner resistance platform is 3mm, the inner side slope angle is 155 DEG, and the outer side slope angle is 97 DEG.

[0016] Beneficial effects:

[0017] The forging process and die design of the present application significantly reduce the raw material loss in the production process of the thin-walled titanium alloy disc-shaped piece, reduce the need for multiple forging, thereby avoiding overburning and reducing the product scrap rate. At the same time, by optimizing the forging process and heat treatment process, the production cycle is shortened, the production cost is reduced, and the production efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the process flowchart of the present application;

[0019] Figure 2 is the structure diagram of the forging die of the present application. DETAILED DESCRIPTION

[0020] The present application will be further described below in conjunction with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application. EXAMPLE

[0021] As Figure 1 shown, a forging process for a thin-walled titanium alloy disc-shaped piece comprises the following steps:

[0022] Step one: cogging (upsetting + piercing)

[0023] The raw material bar is forged twice, the first time is upsetting, and the second time is piercing; the heating temperature of each heating is controlled below 35℃-40℃ of the phase transition point of titanium alloy, and the heating holding time is 120-240 minutes; during upsetting, the deformation of each heating is controlled below 20%, and the uniform speed is pressed by separate hammer, and the pressing speed is controlled at 5-15mm / s; after piercing, the punch is needed for rounding treatment, the pressing amount of each time is not more than 20mm, the uniform speed is pressed, and the pressing speed is less than 10mm / s, so as to eliminate the large R angle and ensure that the piercing and rounding are completed in one heating.

[0024] Step two: ring rolling

[0025] The forged piece after cogging is heated to below 35℃-40℃ of the phase transition point, the heating holding time is 50-170 minutes, and then ring rolling is carried out, and the deformation of each pass is strictly controlled to ensure that the deformation is less than 20%.

[0026] Step three: die forging

[0027] The forged piece after ring rolling is heated again to below 35℃-40℃ of the phase transition point, and the heating holding time is 48-138 minutes; then, the blank is accurately placed in the specially designed forging die, the die is composed of upper and lower dies, and because the forging die is ring-shaped, an internal resistance table is designed, the height of the resistance table is 3mm, the internal slope angle is 155°, and the external slope angle is 97°, so as to prevent the metal from flowing inward; during die forging, the dirt in the die cavity is blown clean by using compressed air, and the die lubricant is uniformly sprayed; then, the blank is placed in the die cavity along the shape of the cavity, positioned by the first hammer, then the preliminary forging is carried out by using a 10mm pad to control the underpressure amount to 10±1mm, and finally the full-load forging is carried out by using a 2mm pad to control the underpressure amount, so as to complete the die forging in one heating.

[0028] Step four: heat treatment

[0029] The forged piece after die forging is immediately sent to the heat treatment furnace, heated to 840℃ and held for 90-100 minutes, and then rapidly cooled by air cooling, at least 8 fans are provided, and the fan rotating speed is set to 1200r / min.

[0030] According to the thin-walled titanium alloy disc-shaped product developed in Example 1, the minimum wall thickness is 14mm, the forming effect is good, there is no scrap, and the raw material utilization rate is increased from 44% to 66%. Example

[0031] As Figure 2As shown, a die for forging thin-walled titanium alloy disc-shaped piece includes an upper die 1 and a lower die, and an inner resistance platform 3 is designed in the upper die or the lower die. Figure 2 In the middle partial enlarged view A), the inner resistance platform 3 has a height of 3 mm, an inner side slope angle of 155°, and an outer side slope angle of 97°.

[0032] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A forging process for thin-walled titanium alloy disk-shaped pieces, characterized in that Comprise the following steps: a. Upsetting forging: two times of fire forging on the raw material bar, upsetting in the first fire, punching in the second fire, the heating temperature is controlled below 35-40℃ of the phase transition point, the heating holding time is 120-240 minutes, the deformation amount of upsetting forging is controlled below 20% per fire, after punching, round the punch, the downward pressure is less than 20mm per time, uniform speed, the downward speed is less than 10mm / s, to eliminate the big R angle, ensure the completion of punching and rounding in the first fire; b. Ring rolling: the heating temperature is controlled below 40℃ of the phase transition point, the heating holding time is 50-170 minutes, the deformation amount is less than 20% per pass in ring rolling; c. Die forging: the forged piece after ring rolling is heated to 35-40℃ below the phase transition point, the heating holding time is 48-138 minutes; then, the blank is accurately placed in the special forging die, in die forging, first, blow off the dirt in the die cavity with compressed air, and evenly spray the die lubricant; then, the blank is placed in the die cavity along the shape of the cavity, the first hammer is used for positioning, then the gasket is used to control the under pressure amount of 10±1mm for preliminary forging, finally, the gasket is used to control the under pressure amount for full load forging, to ensure the completion of die forging in the first fire; d. Heat treatment: the forged piece is put into the warm furnace, 840℃ for 90-100 minutes, air cooling to room temperature; The die in the die forging step is composed of upper and lower dies, and because the forging die is ring-shaped, an internal resistance platform is designed, the resistance platform height is 3mm, the internal slope angle is 155°, and the external slope angle is 97°, to prevent the metal from flowing to the inside.

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