A method for solving the problem of punching cracking of In718plus

Abstract

The present invention provides a method for solving the problem of punching cracking of In718plus, which includes a rolling step after the blanking and punching steps. The rolling step includes three ring rolling steps and a sizing step. By controlling the forging temperature and the corresponding forging deformation amount during the three ring rolling processes, the present invention enables the ring forgings to avoid cracking defects even with a low number of heating passes under high temperature and large deformation. It can not only meet the requirements of mechanical properties and grain size simultaneously, but also reduce the forging cost.

Description

Technical Field

[0001] The present invention relates to the field of processing of ring forgings, and particularly to a method for solving the problem of punching cracking of In718plus. Background Art

[0002] In718 Plus is developed on the basis of Inconel 718. Compared with Inconel 718, the iron content is reduced from 18% to 10%, 9% of cobalt and 1% of tungsten are added, and at the same time, Al+Ti and Al / Ti are adjusted, and the niobium content is appropriately increased. In718plus combines the good comprehensive mechanical properties, hot working and welding properties of In718 alloy and the advantage of higher service temperature of Waspaloy alloy (GH4738), and at the same time overcomes the deficiencies of these two alloys and can be used for a long time at 700°C.

[0003] The forging process for In718 material is not applicable to In718plus material, and some forging defects that are not common in In718 will occur. Especially, a large number of cracking defects occur during the punching process, the amount of product grinding is large, and the defects are difficult to eliminate, which affects the product quality. Summary of the Invention

[0004] To solve the above problems, the present invention proposes a method for solving the punching cracking of In718plus.

[0005] The main content of the present invention includes:

[0006] A method for solving the punching cracking of In718plus, including a rolling step after the blanking and punching steps, and the rolling step includes:

[0007] S1. Heating the punched blank to 1040°C, holding for 50 to 130 minutes and then performing ring rolling. The rolling amount in this heat is 25%-30%, and the operation time is within 120 seconds to obtain a primary ring forging;

[0008] S2. Heating the primary ring forging to 996°C, holding for 30 to 130 minutes and then performing ring rolling. The rolling amount in this heat is 25-30%, and the operation time is within 120 seconds to obtain a secondary ring forging;

[0009] S3. Heating the secondary ring forging to 1010°C, holding for 30 to 130 minutes and then performing ring rolling. The rolling amount in this heat is less than 20%, and the operation time is within 120 seconds to obtain a tertiary ring forging;

[0010] S4. Heating the tertiary ring forging to 955°C, holding for 30 to 120 minutes and then performing full-rounding. The shaping amount is within 1%, and the operation time is within 120 seconds to obtain a final forging.

[0011] Preferably, the blanking and punching step includes: heating the blank to 1100 °C in a high-temperature gas furnace and holding for 90 to 180 minutes; then taking out the blank from the high-temperature gas furnace and transferring it to a 3000T press to upset and punch round holes in the blank to obtain a blank part.

[0012] Preferably, after the rolling step, a solution heat treatment step and an aging heat treatment step are further included.

[0013] Preferably, the solution heat treatment step includes: heating the final forging to 968 °C in a gas-side tilting furnace and holding for 1 hour, and after the holding ends, using a rotary forklift to transfer the final forging to an aqueous quenching liquid within 60 seconds.

[0014] Preferably, the aging heat treatment step includes: transferring the solution heat-treated final forging to a gas-side tilting furnace and heating to 788 °C, holding for 8 hours, cooling to room temperature, and then heating to 704 °C and holding for 8 hours; after the holding ends, using a rotary forklift to transfer the final forging to the air above the rack and air-cooling to room temperature within 60 seconds.

[0015] Preferably, in steps S1, S2, and S3, heating and temperature rise are carried out using a high-temperature gas furnace, and ring rolling is carried out using an R350 ring rolling mill.

[0016] The beneficial effects of the present invention are as follows: The present invention proposes a method for solving the punching cracking of In718plus. By controlling the forging temperature and the corresponding forging deformation amount during the three-ring rolling process, the ring forging can be made not to have cracking defects under high temperature and large deformation using a low-fire process. It can not only meet the requirements of mechanical properties and grain size at the same time, but also reduce the forging cost. Specific Embodiments

[0017] The following will specifically describe the technical solutions protected by the present invention.

[0018] The present invention proposes a method for solving the punching cracking of In718plus, which sequentially includes a blanking and punching step, ring rolling, sizing, solution heat treatment, and aging heat treatment steps. For In718 material, when punching at 1040 °C, a large number of cracking defects will occur. And through the metallographic observation of the cracks, it is found that all cracks start from the surface and then develop along the grain boundaries. At the same time, through metallographic and scanning electron microscope analysis, no distribution of carbides, carbonitrides, or non-metallic inclusions is found at the cracks, nor is there any precipitation of Ni3Nb or Laves phase along the grain boundaries. Therefore, the promoting effect of grain boundary precipitation on intergranular oxidation can be excluded.

[0019] Example 1

[0020] Blank cutting and punching steps: Use a high-temperature gas furnace to heat the blank to 1100°C and hold for 90 minutes; then take the blank out of the high-temperature gas furnace and transfer it to a 3000T press to upset and punch round holes in the blank to obtain a blank part, where the upsetting height ratio is 1.74; through metallographic observation, in this embodiment, the punching process at 1100°C high temperature is adopted, and no cracking defect appears in the blank part.

[0021] Ring rolling steps: The ring rolling steps include a total of three rolling processes and one roundness correction step, and the specific steps are as follows:

[0022] S1. Heat the punched blank part to 1040°C using a high-temperature gas furnace, hold for 50 minutes, and then transfer it to an R350 ring rolling mill for ring rolling. The rolling amount in this heat is 30%, and the operation time is within 120 seconds to obtain a primary ring forging.

[0023] S2. Heat the primary ring forging to 996°C using a high-temperature gas furnace, hold for 30 minutes, and then transfer it to an R350 ring rolling mill for ring rolling. The rolling amount in this heat is 30%, and the operation time is within 120 seconds to obtain a secondary ring forging.

[0024] S3. Heat the secondary ring forging to 1010°C using a high-temperature gas furnace, hold for 30 minutes, and then transfer it to an R350 ring rolling mill for ring rolling. The rolling amount in this heat is 15%, and the operation time is within 120 seconds to obtain a tertiary ring forging.

[0025] S4. Heat the tertiary ring forging to 955°C using a high-temperature gas furnace, hold for 30 minutes, and then transfer it to a 400T sizing machine for roundness correction. The sizing amount is 0.5%, and the operation time is within 120 seconds to obtain a final forging.

[0026] Solution heat treatment step: Heat the final forging to 968°C in a gas-side tilting furnace, hold for 1 hour, and after the holding is completed, use a rotary forklift to transfer the final forging to a water-based quenching liquid, such as AQ3699 of Houghton, and the transfer time is within 60 seconds.

[0027] Ageing heat treatment step: Transfer the final forging after solution heat treatment to a gas-side tilting furnace and heat it to 788°C, hold for 8 hours, cool to room temperature, and then heat it to 704°C and hold for 8 hours; after the holding is completed, use a rotary forklift to transfer the final forging to the material rack and air-cool it to room temperature, and the transfer time is within 60 seconds.

[0028] Example 2

[0029] Blank cutting and punching steps: Use a high-temperature gas furnace to heat the blank to 1100°C and hold for 180 minutes; then take the blank out of the high-temperature gas furnace and transfer it to a 3000T press to upset and punch round holes in the blank to obtain a blank part, where the upsetting height ratio is 1.74.

[0030] Ring rolling steps: The specific steps are as follows:

[0031] S1. Heat the punched blank to 1040°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling reduction in this heat treatment is 25%, and the operation time is within 120 seconds to obtain the primary ring forging.

[0032] S2. Heat the primary ring forging to 996°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling reduction in this heat treatment is 25%, and the operation time is within 120 seconds to obtain the secondary ring forging.

[0033] S3. Heat the secondary ring forging to 1010°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling reduction in this heat treatment is 10%, and the operation time is within 120 seconds to obtain the tertiary ring forging.

[0034] S4. Heat the tertiary ring forging to 955°C using a high-temperature gas furnace, hold for 120 minutes, then transfer it to a 400T sizing press for sizing. The sizing reduction is 0.5%, and the operation time is within 120 seconds to obtain the final forging.

[0035] Solution heat treatment step: Heat the final forging to 968°C in a gas-side tilting furnace, hold for 1 hour. After the holding is completed, use a rotary forklift to transfer the final forging to a water-based quenching liquid, and the transfer time is within 60 seconds.

[0036] Ageing heat treatment step: Transfer the solution heat-treated final forging to a gas-side tilting furnace and heat it to 788°C, hold for 8 hours, cool to room temperature, then heat it to 704°C and hold for 8 hours. After the holding is completed, use a rotary forklift to transfer the final forging to the rack and air-cool it to room temperature, and the transfer time is within 60 seconds.

[0037] Example 3

[0038] Blank cutting and punching steps: Heat the blank to 1100°C using a high-temperature gas furnace and hold for 180 minutes. 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 in the blank to obtain the blank part, where the upsetting height ratio is 2.32.

[0039] Ring rolling steps: The specific steps are as follows:

[0040] S1. Heat the punched blank to 1040°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling reduction in this heat treatment is 30%, and the operation time is within 120 seconds to obtain the primary ring forging.

[0041] S2. Heat the primary ring forging to 996°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling amount for this heat is 30%, and the operation time is within 120 seconds to obtain the secondary ring forging.

[0042] S3. Heat the secondary ring forging to 1010°C using a high-temperature gas furnace, hold for 130 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling amount for this heat is 15%, and the operation time is within 120 seconds to obtain the tertiary ring forging.

[0043] S4. Heat the tertiary ring forging to 955°C using a high-temperature gas furnace, hold for 120 minutes, then transfer it to a 400T sizing press for sizing. The sizing amount is 0.5%, and the operation time is within 120 seconds to obtain the final forging.

[0044] Solution heat treatment step: Heat the final forging to 968°C in a gas-side tilting furnace, hold for 1 hour. After the holding is completed, use a rotary forklift to transfer the final forging to the water-based quenching liquid, and the transfer time is within 60 seconds.

[0045] Aging heat treatment step: Transfer the solution heat-treated final forging to a gas-side tilting furnace and heat it to 788°C, hold for 8 hours, cool to room temperature, then heat it to 704°C and hold for 8 hours. After the holding is completed, use a rotary forklift to transfer the final forging to the rack and air-cool it to room temperature, and the transfer time is within 60 seconds.

[0046] Example 4

[0047] Blanking and punching step: Heat the blank to 1100°C using a high-temperature gas furnace and hold for 90 minutes. Then, after taking the blank out of the high-temperature gas furnace, transfer it to a 3000T press to upset and punch a round hole in the blank to obtain a blank part, where the upsetting height ratio is 2.32.

[0048] Ring rolling step: The specific steps are as follows:

[0049] S1. Heat the punched blank part to 1040°C using a high-temperature gas furnace, hold for 50 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling amount for this heat is 25%, and the operation time is within 120 seconds to obtain the primary ring forging.

[0050] S2. Heat the primary ring forging to 996°C using a high-temperature gas furnace, hold for 30 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling amount for this heat is 25%, and the operation time is within 120 seconds to obtain the secondary ring forging.

[0051] S3. Heat the secondary ring forging to 1010°C in a high-temperature gas furnace, hold for 30 minutes, then transfer it to the R350 ring rolling mill for ring rolling. The rolling amount for this heat treatment is 10%, and the operation time is within 120 seconds to obtain the tertiary ring forging.

[0052] S4. Heat the tertiary ring forging to 955°C in a high-temperature gas furnace, hold for 30 minutes, then transfer it to a 400T shaping machine for circular shaping. The shaping amount is 0.5%, and the operation time is within 120 seconds to obtain the final forging.

[0053] Solution heat treatment step: Heat the final forging to 968°C in a gas-side tilting furnace, hold for 1 hour. After the holding is completed, use a rotary forklift to transfer the final forging to the water-based quenching liquid, and the transfer time is within 60 seconds.

[0054] Aging heat treatment step: Transfer the final forging after solution heat treatment to a gas-side tilting furnace, heat to 788°C, hold for 8 hours, cool to room temperature, then heat to 704°C and hold for 8 hours. After the holding is completed, use a rotary forklift to transfer the final forging to the rack and air-cool it to room temperature, and the transfer time is within 60 seconds.

[0055] In the forging process of the present invention after heat treatment, not only no cracking defects occur during forging, but also the grain size of the product does not increase significantly, and its mechanical properties can meet the standard requirements.

[0056] The above are only embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A method for solving the problem of punching cracking of In718plus, characterized in that, Including a rolling step after the blanking and punching steps, the rolling step includes: S1. Heating the blank after punching to 1040 °C, holding for 50 to 130 minutes, and then performing ring rolling. The rolling amount in this heat treatment is 25%-30%, and the operation time is within 120 seconds to obtain a primary ring forging; S2. Heating the primary ring forging to 996 °C, holding for 30 to 130 minutes, and then performing ring rolling. The rolling amount in this heat treatment is 25-30%, and the operation time is within 120 seconds to obtain a secondary ring forging; S3. Heating the secondary ring forging to 1010 °C, holding for 30 to 130 minutes, and then performing ring rolling. The rolling amount in this heat treatment is less than 20%, and the operation time is within 120 seconds to obtain a tertiary ring forging; S4. Heating the tertiary ring forging to 955 °C, holding for 30 to 120 minutes, and then performing full-round shaping. The shaping amount is within 1%, and the operation time is within 120 seconds to obtain a final forging. Wherein after the rolling step, there are also a solution heat treatment step and an aging heat treatment step. The aging heat treatment step includes: Transferring the final forging after solution heat treatment to a gas-side tilting furnace, heating it to 788 °C, holding for 8 hours, cooling to room temperature, and then heating it to 704 °C and holding for 8 hours; after the holding is completed, using a rotary forklift to transfer the final forging to a rack and air-cooling it to room temperature. The transfer time is within 60 seconds.

2. A method for solving the punching cracking of In718plus according to claim 1, characterized in that The blanking and punching steps include: heating the blank to 1100 °C in a high-temperature gas furnace and holding for 90 to 180 minutes; then taking the blank out of the high-temperature gas furnace and transferring it to a 3000T press to upset and punch a round hole in the blank to obtain a blank.

3. A method for solving the punching cracking of In718plus according to claim 1, characterized in that, The solution heat treatment step includes: heating the final forging to 968 °C in a gas-side tilting furnace and holding for 1 hour. After the holding is completed, using a rotary forklift to transfer the final forging to an aqueous quenching liquid. The transfer time is within 60 seconds.

4. A method for solving the punching cracking of In718plus according to claim 1, characterized in that In steps S1, S2, and S3, heating is carried out using a high-temperature gas furnace, and ring rolling is carried out using an R350 ring rolling mill.