Backward extrusion blank making method for high-temperature alloy casing ring piece

Abstract

The invention discloses a backward extrusion blank making method for a high-temperature alloy casing ring piece, which is characterized in that an upset cake blank is placed in a special forming die, and a special punch is used for performing backward extrusion upsetting punching in the forming die, so that a blank which is free of large bulging degree, free of large R angle at the sharp corner of the end surface and good in surface quality is prepared. A foundation is laid for subsequent preparation of good-quality annular forgings, when conventional free upsetting and punching are adopted, the thickness of a punching bottom sheet is large, the material utilization rate is low, when closed backward extrusion punching is adopted, the thickness of the punching bottom sheet is small, the weight is light, the material utilization rate is greatly increased, and especially for expensive materials such as high-temperature alloy and titanium alloy, the cost is low. And the raw material cost is effectively saved. The method is suitable for production of the thin-wall high-cylinder annular forgings.

Description

Technical Field

[0001] The present invention relates to a method for blank making of a ring part, and particularly to a method for backward extrusion blank making of a high-temperature alloy casing ring part. Background Art

[0002] The current upsetting and punching method for thin-walled ring forgings is as follows: After heating the bar stock to the deformation temperature and holding it for a period of time, use the upper anvil of a press or a forging hammer to press the height of the bar stock to a solid cake blank of a certain height. Select a suitable punch according to the diameter of the mandrel of the ring rolling mill. Place the small end of the punch on the upper end face of the cake blank, use the upper anvil of the press to press the punch down by a certain height, take out the punch, turn the cake blank 180°, and select a matching shear punch to shear and punch the bottom film; for ring forgings with a short ring blank height and a relatively thick wall thickness, using this method of free upsetting and punching for blank preparation is easy to operate and has high production efficiency; for ring forgings with a high ring blank height and a thin wall thickness, using the conventional free upsetting and punching preparation method, it is easy to pull the material in the height direction during the punching process, and the height of the prepared blank does not meet the requirements of the process design. Moreover, the R angle of the prepared blank is relatively large. For ring forgings with a small deformation amount, due to the lack of a large deformation amount, the R angle remains after rolling and cannot meet the drawing requirements during the rolling process; the currently commonly used improvement method is to use mandrel drawing to increase the height of the shortened blank. This blank making method has a complex operation process, requires multiple heating passes, and cracks and folds are likely to occur in the blank during the mandrel drawing process, and even out-of-tolerance products may appear in severe cases. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a method for manufacturing a blank by closed backward extrusion punching, which uses a special punch to perform backward extrusion upsetting and punching in a die to realize the closed backward extrusion punching blank making of a thin-walled high-cylinder ring forging. The blank prepared by this method has no large bulges, no large R angle at the end face sharp corners, good surface quality, and high material utilization rate.

[0004] To solve the above problems, the technical solution of the method for backward extrusion blank making of the high-temperature alloy casing ring part of the present invention includes the following steps:

[0005] Die upsetting: Cut the material according to the specifications, apply a special glass lubricant to the upper and lower end faces and the circumferential surface of the bar stock, and place the bar stock in a forging heating furnace for heating; take out the heated bar stock and perform upsetting; evenly place the bar stock at the center of the upsetting die, and under the action of a press, upset the bar stock into a cake blank;

[0006] Pre-punching: Perform pre-punching on the cake blank. Place a special pre-punching punch on the upper end of the cake blank, and under the action of a press, press the special pre-punching punch into the cake blank, and then take out the special pre-punching punch;

[0007] Backward extrusion punching: Perform backward extrusion punching on the cake blank. Place the cake blank evenly at the center of the backward extrusion die set, and place a special cushion plate below the cake blank; Remove the backward extrusion punch, apply graphite lubricant to the lower end face and circumferential surface of the backward extrusion punch, and place the backward extrusion punch on the pre-punched blind hole at the upper end of the cake blank. Use the upper anvil of the press to press the punch until the upper hammer anvil contacts the upper end face of the backward extrusion die set, and then remove the blind hole blank;

[0008] Punching through hole: Punch through the blind hole blank. Place the punching end of the blind hole blank on the upper end face of the leakage basin, and use a special shear punch to shear the punching bottom film to obtain a backward extrusion punching blank.

[0009] Preferably, the punching depth of the pre-punched hole is 15% - 20% of the height of the cake blank.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0011] For the method for preparing a high-temperature alloy casing ring blank by backward extrusion of the present invention, the blank prepared by closed backward extrusion has no large bulges, no large R corners at the end face sharp corners, and good surface quality, laying a foundation for the subsequent preparation of a ring forging with good quality; The hole type punched by the pre-punched hole is beneficial to improving the material flow uniformity during the backward extrusion punching of the blank; And when using conventional free upsetting and punching, the thickness of the punching bottom film is large and the material utilization rate is low, while using closed backward extrusion punching, the thickness of the punching bottom film is thin and the weight is light, greatly improving the material utilization rate. Especially for very expensive materials such as high-temperature alloys and titanium alloys, the raw material cost is effectively saved. Brief Description of the Drawings

[0012] The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0013] Figure 1 is a schematic diagram of die set upsetting;

[0014] Figure 2 is a schematic diagram of pre-punching;

[0015] Figure 3 is a schematic diagram of backward extrusion punching;

[0016] Figure 4 is a schematic diagram of shearing and punching through the hole;

[0017] Figure 5 is a schematic diagram of the structure of a thin-walled high-cylinder ring blank. Detailed Description of the Embodiments

[0018] To implement the method for preparing a high-temperature alloy casing ring blank by backward extrusion of the present invention, equipment such as a forging press, a high-temperature electric furnace, and an operating machine need to be provided. The specific implementation of this method is as follows:

[0019] Cut the material according to the specifications, apply special glass lubricant to the upper and lower end faces and the circumferential surface of the bar stock, and place the bar stock in a forging heating furnace for heating; take out the heated bar stock and perform upsetting; as Figure 1 shown, evenly place the bar stock 10 at the center of the upsetting die 20, and under the action of a press, upset the bar stock 10 into a cake blank 11;

[0020] Perform pre-punching on the cake blank 11. As Figure 2 shown, place a special pre-punching punch 21 on the upper end of the cake blank 11, and under the action of a press, press the special pre-punching punch 21 into the cake blank 11 to a depth of 20% of the height of the cake blank 11, and then take out the special pre-punching punch 21;

[0021] Perform backward extrusion punching on the cake blank 11. As Figure 3 shown, evenly place the cake blank 11 at the center of the backward extrusion die 22, and place a special cushion plate 24 under the cake blank 11; take out the backward extrusion punch 25, apply graphite lubricant to the lower end face and the circumferential surface of the backward extrusion punch 25, and place the backward extrusion punch 25 on the pre-punched blind hole at the upper end of the cake blank 11. Use the upper anvil of the press to press the punch until the upper hammer anvil contacts the upper end face of the backward extrusion die 22, and take out the blind hole blank 12;

[0022] Perform through-hole punching on the blind hole blank. As Figure 4 shown, place the punching end of the blind hole blank 12 on the upper end face of the drain pan 26, and use a special shearing punch 27 to shear the punching bottom sheet to obtain a backward extrusion punched blank 13, as Figure 5 shown.

Claims

1. A method for preparing a blank of a high-temperature alloy casing ring by backward extrusion, characterized in that: The steps are as follows: Blank upsetting of the diaphragm: Cut the material according to the specifications, apply special glass lubricant on the upper and lower end faces and the circumferential surface of the bar stock, and place the bar stock in a forging heating furnace for heating; Take out the heated bar stock and perform upsetting; Place the bar stock evenly at the center of the upsetting diaphragm, and under the action of a press, upset the bar stock into a cake blank; Pre-punching: Perform pre-punching on the cake blank. Place a special pre-punching punch on the upper end of the cake blank, and under the action of a press, press the special pre-punching punch into the cake blank, and then take out the special pre-punching punch; Reverse extrusion punching: Perform reverse extrusion punching on the cake blank. Place the cake blank evenly at the center of the reverse extrusion diaphragm, and place a special cushion plate under the cake blank; Take out the reverse extrusion punch, apply graphite lubricant on the lower end face and the circumferential surface of the reverse extrusion punch, and place the reverse extrusion punch on the pre-punched blind hole at the upper end of the cake blank. Use the upper anvil of the press to press the punch until the upper hammer anvil contacts the upper end face of the reverse extrusion diaphragm, and take out the blind hole blank; Punching through hole: Punch through the hole of the blind hole blank. Place the punching end of the blind hole blank on the upper end face of the drain pan, and use a special shear punch to shear the punching bottom sheet to obtain a reverse extrusion punching blank.

2. The method for preparing a blank by backward extrusion of a superalloy casing ring according to claim 1, characterized in that: The punching depth of the pre-punching is 15% - 20% of the height of the cake blank.

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