Hot working process for improving mechanical property of 718plus alloy forge piece

Abstract

The invention provides a hot working process for improving the mechanical property of a 718plus alloy forge piece. The hot working process comprises the steps of blanking, punching, rolling, solid solution heat treatment and rapid cooling. According to the method, the forging temperature and the heat treatment cooling mode are reasonably controlled, and the content of a precipitated phase eta is controlled, so that the mechanical property of the alloy is improved, the cracking risk of the 718plus alloy is reduced, and the possibility of scrapping or reworking is reduced.

Description

Technical Field

[0001] The invention relates to the field of aviation parts manufacturing, and in particular to a hot working process for improving the mechanical properties of 718plus alloy forgings. Background Art

[0002] Traditional 718 alloy is widely used in aircraft engine turbine disk materials due to its excellent performance and low price. However, with the upgrading of aircraft engines, the operating temperature of turbine disks has exceeded the upper limit of the use temperature of 718 alloy. Although the existing WASPALOY alloy has a higher temperature bearing capacity than 718 alloy, it is difficult to form and has poor welding performance.

[0003] 718plus alloy combines the good forming performance and low cost of 718 alloy with the strong temperature bearing capacity of WASPALOY alloy, making it an ideal material for current aircraft engines.

[0004] However, 781plus alloy is a high-temperature alloy that is very easy to crack. In order to reduce the scrapping or rework caused by cracking, the ring forgings are currently heated and kept at a temperature above 900°C, and after a ring rolling process with multiple fires and small deformation, they are subjected to solid solution and aging heat treatment according to the material standards. The mechanical properties of the ring forgings obtained fluctuate greatly, especially the plasticity, which is very easy to fail. In particular, the ring rolling process with multiple fires and small deformation further increases the risk of mechanical properties failing. In addition, the existing material specifications do not specify the solid solution cooling method. Summary of the invention

[0005] To solve the above problems, the present invention proposes a hot working process for improving the mechanical properties of 718plus alloy forgings, which can improve the mechanical properties of 718plus alloy, meet the product performance requirements of different customers, and reduce scrapping or rework caused by unqualified mechanical properties.

[0006] The main contents of the present invention include: a hot working process for improving the mechanical properties of 718plus alloy forgings, comprising the following steps:

[0007] A hot working process for improving the mechanical properties of 718plus alloy forgings comprises the following steps:

[0008] S1. Cutting: cutting according to process requirements;

[0009] S2, punching step: heating the blank to 980-1270°C in a heating furnace, keeping the temperature for 0.5 to 5 hours, then taking the blank out of the heating furnace and transferring it to a press to perform upsetting and punching on the blank;

[0010] S3, rolling step: heating the blank after punching to 950-1100°C in a heating furnace, keeping the temperature for 0.5 to 5 hours, then taking the ring forging out of the heating furnace and transferring it to a ring rolling mill, performing multiple heat direct rolling on the ring forging, and controlling the deformation amount to 15%-30%;

[0011] S4. Solution heat treatment: The forgings are subjected to solution heat treatment in a heat treatment furnace;

[0012] S5. Cooling: Use quenching liquid to quickly cool the forging.

[0013] Preferably, the heating furnace in steps S2 and S3 uses a high-temperature gas furnace for heating.

[0014] Preferably, the press in step S2 is a 3000T press.

[0015] Preferably, the operation time in step S2 is controlled to be completed within 180 seconds.

[0016] Preferably, the ring rolling mill in step S3 is an R350 ring rolling mill.

[0017] Preferably, step S5 further includes a step of performing dimensional inspection on the forging according to the drawing requirements.

[0018] The beneficial effects of the present invention are as follows: a hot working process for improving the mechanical properties of 718plus alloy forgings proposed by the present invention controls the content of the precipitated phase η by reasonably controlling the forging temperature and the heat treatment cooling method, thereby improving the mechanical properties of the alloy, reducing the risk of cracking of the 718plus alloy, and reducing the possibility of scrapping or rework. DETAILED DESCRIPTION

[0019] The technical solution protected by the present invention is described in detail below.

[0020] Example 1

[0021] A hot working process for improving the mechanical properties of 718plus alloy forgings comprises the following steps:

[0022] S1. Cutting: cutting according to process requirements;

[0023] S2, punching step: using a high-temperature gas furnace to heat the blank to 980°C, keeping the temperature for 3 hours, then taking the blank out of the high-temperature gas furnace and transferring it to a press, upsetting the blank and punching a round hole, the operation time is controlled to be completed within 180 seconds;

[0024] S3, rolling step: using a high-temperature gas furnace to heat the blank after punching to 950°C, keeping the temperature for 2 hours, then taking the ring forging out of the high-temperature gas furnace and transferring it to a ring rolling mill, performing multiple rounds of direct rolling on the ring forging, the rolling amount of each round should be controlled at 15%, and the operation time should be controlled within 180 seconds;

[0025] S4. Solution heat treatment: Heat the forging to 960°C in a gas-fired side-lift furnace and keep it warm for 1 hour. After the insulation is completed, use quenching liquid to quickly cool the forging.

[0026] Example 2

[0027] A hot working process for improving the mechanical properties of 718plus alloy forgings comprises the following steps:

[0028] S1. Cutting: cutting according to process requirements;

[0029] S2, punching step: use a high-temperature gas furnace to heat the blank to 1270°C, keep it warm for 1.5 hours, then take the blank out of the high-temperature gas furnace and transfer it to a 3000T press to upset and punch a round hole on the blank. The operation time is controlled to be completed within 180 seconds;

[0030] S3, rolling step: using a high-temperature gas furnace to heat the blank after punching to 1100°C, keeping the temperature for 0.5 hours, then taking the ring forging out of the high-temperature gas furnace and transferring it to the R350 ring rolling mill, performing multiple rounds of direct rolling on the ring forging, the rolling amount of each round should be controlled at 30%, and the operation time should be controlled within 120 seconds;

[0031] S4. Solution heat treatment: Heat the forging to 960°C in a gas-fired side-lift furnace and keep it warm for 1 hour. After the insulation is completed, use quenching liquid to quickly cool the forging.

[0032] Example 3

[0033] A hot working process for improving the mechanical properties of 718plus alloy forgings comprises the following steps:

[0034] S1. Cutting: cutting according to process requirements;

[0035] S2, punching step: using a high-temperature gas furnace to heat the blank to 1100°C, keeping the temperature for 1.5 hours, then taking the blank out of the high-temperature gas furnace and transferring it to a press, upsetting the blank and punching a round hole, the operation time is controlled to be completed within 180 seconds;

[0036] S3, rolling step: using a high-temperature gas furnace to heat the blank after punching to 1040°C, keeping the temperature for 0.5 hours, then taking the ring forging out of the high-temperature gas furnace and transferring it to the R350 ring rolling mill, performing multiple rounds of direct rolling on the ring forging, the rolling amount of each round should be controlled at 15%, and the operation time should be controlled within 120 seconds;

[0037] S4. Solution heat treatment: Heat the forging to 960°C in a gas-fired side-lift furnace and keep it warm for 1 hour. After the insulation is completed, use quenching liquid to quickly cool the forging.

[0038] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A hot working process for improving the mechanical properties of 718plus alloy forgings, characterized in that: The steps include: S1. Cutting: cutting according to process requirements; S2, punching step: heating the blank to 980-1270°C in a heating furnace, keeping the temperature for 0.5 to 5 hours, then taking the blank out of the heating furnace and transferring it to a press, upsetting the blank and punching a round hole; S3, rolling step: heating the blank after punching to 950-1100°C in a heating furnace, keeping the temperature for 0.5 to 5 hours, then taking the ring forging out of the heating furnace and transferring it to a ring rolling mill, performing multiple heat direct rolling on the ring forging, and controlling the deformation amount to 15%-30%; S4. Solution heat treatment: The forgings are subjected to solution heat treatment in a heat treatment furnace; S5. Cooling: Use quenching liquid to quickly cool the forging.

2. A hot working process for improving the mechanical properties of 718plus alloy forgings according to claim 1, characterized in that: The heating furnace in steps S2 and S3 uses a high-temperature gas furnace for heating.

3. A hot working process for improving the mechanical properties of 718plus alloy forgings according to claim 1, characterized in that: The press in step S2 is a 3000T press.

4. A hot working process for improving the mechanical properties of 718plus alloy forgings according to claim 1, characterized in that: The operation time in step S2 is controlled to be completed within 180 seconds.

5. A hot working process for improving the mechanical properties of 718plus alloy forgings according to claim 1, characterized in that: The ring rolling mill in step S3 is a R350 ring rolling mill.

6. A hot working process for improving the mechanical properties of 718plus alloy forgings according to claim 1, characterized in that: After step S5, the process also includes the step of inspecting the dimensions of the forging according to the drawing requirements.