A forging method for refining grain size of GH4169 ring forgings by 1T electro-hydraulic hammer

Abstract

The application discloses a forging method for refining grain size of GH4169 ring forgings by 1T electro-hydraulic hammer, which is used for producing compression nuts on an aero-engine and comprises the following steps: blanking, machining, turning an inner hole, rounding a corner, heating, 1st fire forging, heating of a hot blank, 2nd fire forging, heating of a hot blank, 3rd fire forging, heating of a hot blank, final forging forming and physical and chemical detection. The forging technology of the ring forgings solves the problems of (1) refining the average grain size of the forgings and (2) improving the qualified rate of the ring forgings.

Description

Technical Field

[0001] This invention discloses a forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer, belonging to the field of high-temperature alloy forging technology. Background Technology

[0002] Typically, ring forgings made of GH4169 high-temperature alloy are free forged, mainly used in the production of clamping nuts for aero engines. These forgings have high performance requirements, including an average grain size of grade 5 or higher to meet design specifications. Forging GH4169 high-temperature alloy forgings using small equipment like a 1T electro-hydraulic hammer and achieving an average grain size of grade 5 has always been quite challenging. Because the microstructure of this alloy is particularly sensitive to temperature, forgings produced using previous methods often had an average grain size of only grade 4 or lower, resulting in performance indicators far below design requirements.

[0003] The shortcomings of existing technology include: 1. Direct forging from bar stock results in forgings with an average grain size of only grade 4 or lower, and performance indicators are far below design requirements.

[0004] 2. The hot working properties of GH4169 bar stock are not ideal. It is difficult to forge and deform it using a small device such as a 1T electro-hydraulic hammer, making the processing quite difficult.

[0005] 3. The original forging process is as follows: raw material procurement, blanking, heating, upsetting, punching, hot billet reheating, 2-fire forging, hot billet reheating, 3-fire forging, hot billet reheating, 4-fire forging, hot billet reheating, final forging, sampling, and testing. However, this material is difficult to punch and is prone to cracking when forged in the range of 980℃ to 1010℃. Summary of the Invention

[0006] To overcome the aforementioned shortcomings, a new process route was adopted through technological innovation, and the forging temperature and deformation amount per forging pass were controlled, thereby enabling the forged ring forgings to obtain a uniform fine-grained structure. This invention, through technological innovation, improves the average grain size of this series of forgings to level 7-8, meeting the design requirements.

[0007] The technical solution of the present invention is as follows: A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer, for producing clamping nuts for aero engines, includes the following steps: Raw material procurement; Material feeding; Machining, hole turning; Machining, chamfering; Heating: The bar stock with chamfered holes is heated to 980℃~1010℃ in a box furnace and held for 15min~75min. The shortest holding time is calculated as: effective thickness mm × 0.4min / mm; the longest holding time is calculated as: effective thickness mm × 0.4 (min / mm) + 60min. 1. Fire forging: After processing in step (5), the bar stock is placed on the 1T electro-hydraulic hammer workbench and the hole is enlarged using a frame. The hot billet is reheated in a box furnace. The bar stock after the first forging in step (6) is heated to 980℃~1010℃ in a box furnace and held for 7min~67min. The shortest holding time is calculated as: effective thickness mm×0.2min / mm. The longest holding time is calculated as: effective thickness mm×0.2min / mm+60min. 2. Fire forging: After processing in step (7), the bar stock is placed on the 1T electro-hydraulic hammer workbench and the hole is enlarged for the second time using a frame. The hot billet is reheated in a box furnace. The bar stock after the second forging in step (8) is heated to 980℃~1010℃ in a box furnace and held for 7min~67min. The shortest holding time is calculated as: effective thickness mm×0.2min / mm. The longest holding time is calculated as: effective thickness mm×0.2min / mm+60min. 3. Fire forging: Place the bar material processed in step (9) onto the 1T electro-hydraulic hammer workbench and perform three hole enlargements using a frame. The hot billet is reheated in a box furnace. The bar stock after the 3-fire forging in step (10) is heated to 980℃~1010℃ in a box furnace and held for 7min~67min. The shortest holding time is calculated as: effective thickness mm×0.2min / mm. The longest holding time is calculated as: effective thickness mm×0.2min / mm+60min. For final forging, the bar material processed in step (11) is placed on the 1T electro-hydraulic hammer workbench to flatten both end faces.

[0008] Sampling and testing: Samples were taken from the ring forging for grain size testing.

[0009] Preferably, in step (1) above, the raw materials are purchased in accordance with the Q / S10-0313-2004 standard, with Φ120 rods and a grain size greater than grade 5.

[0010] Preferably, the blanking size in step (2) above is Φ120×50, in mm.

[0011] Preferably, the size of the machine hole in step (3) above is Φ50, in mm.

[0012] Preferably, in step (4) above, the fillet radius of the bar stock after drilling is R5 to R10, in mm.

[0013] Preferably, the size of the hole after expansion in step (6) is Φ120±5×Φ60±5×50±3 mm.

[0014] Preferably, the size of the expanded hole after 2-fire forging in step (8) above is Φ130±5×Φ80±5×50±3, in mm.

[0015] Preferably, the size of the expanded hole after three-fire forging in step (10) is Φ140±5×Φ95±5×50±3, in mm.

[0016] Preferably, the dimensions after flattening both ends in step (12) above are Φ150±5×Φ950-5×38+50, in mm.

[0017] The beneficial effects of this invention are: The forging technology for ring forgings of this invention solves the following problems: (1) Refine the average grain size of the forgings.

[0018] (2) Improve the finished product qualification rate of ring forgings.

[0019] (3) The upsetting and punching steps were replaced by machining on the original forging steps, thereby reducing the number of forging passes and avoiding the difficulty of punching the material. Attached Figure Description

[0020] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is a schematic diagram of a forging; Figure 3 It optimizes the grain size of the forgings before processing; Figure 4 It refers to the optimized grain size of the forging. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example

[0022] like Figure 1 As shown, a forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer is described. The ring forging is as follows: Figure 2 As shown, the production of clamping nuts for aircraft engines includes the following steps: Raw material procurement and control: Φ120 bars are procured from designated qualified suppliers in accordance with the Q / S10-0313-2004 standard. The bars are re-tested for chemical composition, mechanical properties, low magnification structure, grain size (required to be greater than level 5), and flaw detection (inspection of internal quality level A).

[0023] Cut the material; the dimensions are Φ120×50.

[0024] Machining, drilling (machine a Φ50 hole in the center of a Φ120×50 bar stock).

[0025] Machining, chamfering (rounding the bar stock after turning holes to R5~R10). Heating: The bar stock with the chamfered bore is heated to 1010℃ in a box furnace and held for 15 to 75 minutes.

[0026] For the first heat forging, the bar stock is placed on a 1T electro-hydraulic hammer workbench and enlarged using a frame. The enlarged dimensions are Φ120±5×Φ60±5×50±3.

[0027] The hot billet is reheated in a box furnace to 1010°C and held for 7 to 67 minutes.

[0028] For the second forging, the bar stock is placed on a 1T electro-hydraulic hammer workbench and enlarged using a frame. The enlarged dimensions are Φ130±5×Φ80±5×50±3.

[0029] The hot billet is reheated in a box furnace to 1010℃, and the holding time is 7min to 67min.

[0030] Forging is performed using a 3-fire method. The bar stock is placed on a 1T electro-hydraulic hammer workbench and enlarged using a frame. The enlarged dimensions are Φ140±5×Φ95±5×50±3.

[0031] The hot billet is reheated in a box furnace to 1010°C and held for 7 to 67 minutes.

[0032] For final forging, the bar stock is placed on a 1T electro-hydraulic hammer workbench to flatten both end faces. The dimensions after flattening the end faces are Φ150±5×Φ95. 0 -5 ×38 +5 0.

[0033] Sampling and testing: Samples were taken from the ring forging for grain size testing, such as... Figure 4 As shown, the average grain size of this forging is grade 8, as... Figure 3 The image shows the grain size of the forging before optimization, with an average grain size of 3.5.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical 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 forging method for refining grain size of GH4169 ring forgings with 1T electro-hydraulic hammer for producing compression nuts on aero-engine, characterized in that Includes the following steps: (1) Raw material procurement; (2) Feeding; (3) Machining, hole turning; (4) Machining, chamfering; (5) Heating: Heat the bar stock after chamfering the machined holes to 980°C to 1010°C in a box furnace and hold for 15 min to 75 min. The shortest insulation time is calculated as: effective thickness (mm) × 0.4 min / mm; the longest insulation time is calculated as: effective thickness (mm) × 0.4 min / mm + 60 min. (6) 1. Fire forging: Place the bar stock processed in step (5) onto the 1T electro-hydraulic hammer workbench and enlarge the hole using a frame. (7) Hot billet reheating: The bar stock after the first heat forging in step (6) is heated to 980°C to 1010°C in a box furnace and held for 7 min to 67 min. The shortest holding time is calculated as: effective thickness mm × 0.2 min / mm. The longest holding time is calculated as: effective thickness mm × 0.2 min / mm + 60 min. (8) 2. Fire forging: After processing in step (7), the bar stock is placed on the 1T electro-hydraulic hammer workbench and the hole is enlarged for the second time using a frame. (9) Hot billet reheating: The bar stock after the second forging in step (8) is heated to 980°C to 1010°C in a box furnace and held for 7 min to 67 min. The shortest holding time is calculated as: effective thickness mm × 0.2 min / mm. The longest holding time is calculated as: effective thickness mm × 0.2 min / mm + 60 min. (10) 3 Fire forging: Place the bar material processed in step (9) onto the 1T electro-hydraulic hammer workbench and perform three-stage hole enlargement using a frame; (11) Hot billet reheating: The bar stock after the 3-fire forging in step (10) is heated to 980°C to 1010°C in a box furnace and held for 7 min to 67 min. The shortest holding time is calculated as: effective thickness mm × 0.2 min / mm. The longest holding time is calculated as: effective thickness mm × 0.2 min / mm + 60 min. (12) Final forging: Place the bar stock processed in step (11) onto the 1T electro-hydraulic hammer workbench to flatten both end faces; (13) Sampling and testing: Take a sample from the ring forging for grain size testing.

2. The method of claim 1, wherein the method is characterized by In step (1), the raw materials are purchased in accordance with the Q / S10-0313-2004 standard, with Φ120 bars and a grain size greater than grade 5.

3. The method of claim 2, wherein the method is characterized by The blanking size in step (2) is Φ120×50, in mm.

4. The method of claim 3, wherein the method is characterized by The size of the machine hole in step (3) is Φ50, in mm.

5. A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer according to claim 4, characterized in that... In step (4), the fillet radius of the bar stock after drilling is R5 to R10, in mm.

6. A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer according to claim 5, characterized in that... The dimensions of the expanded hole after the first forging in step (6) are Φ120±5×Φ60±5×50±3, in mm.

7. A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer according to claim 6, characterized in that... The dimensions of the expanded hole after the 2-fire forging in step (8) are Φ130±5×Φ80±5×50±3, in mm.

8. A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer according to claim 7, characterized in that... The dimensions of the expanded hole after the 3-fire forging in step (10) are Φ140±5×Φ95±5×50±3, in mm.

9. A forging method for refining the grain size of GH4169 ring forgings using a 1T electro-hydraulic hammer according to claim 8, characterized in that... The size of the step (12) after the two end faces are flattened is Φ150±5xΦ95 0 -5 x 38 +5 0, unit: mm.

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