A sub-temperature carburizing heat treatment method for reducing heat treatment deformation of thin-walled gears

A technology of heat treatment deformation and heat treatment method, applied in the field of heat treatment, can solve the problems of large heat treatment deformation of thin-walled gears, and achieve the effects of shortening carburizing time, reducing thermal stress deformation, and reducing energy consumption

Active Publication Date: 2021-09-14
WUHAN UNIV OF TECH
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Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a sub-temperature carburizing heat treatment method for reducing heat treatment deformation of thin-walled gears, which can solve the problem of existing thin-walled gears while satisfying the high surface hardness and high wear resistance of thin-walled gears. The problem of large heat treatment deformation of gears

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  • A sub-temperature carburizing heat treatment method for reducing heat treatment deformation of thin-walled gears
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[0023] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] like figure 1 As shown, this embodiment takes a certain type of gear made of 20CrMnTiH as an example. The forging adopts a hot forging forming process, and its carburizing heat treatment method is realized according to the following steps:

[0025] (1) Sub-temperature normalizing in advance: Gradiently heat the thin-walled gear forgings to 550°C for 0.5h, then heat to 860-880°C, keep warm for 2-3h, then take out the furnace and air-cool to room temperature, according to the size of the thin-walled gear forgings , reasonably control the cooling rate at 5°C / s~10°C / s.

[0026] (2) Slow-speed shot peening: The thin-walled gear forgings that have been pre-treated by sub-temperature normalizing are subjected to slow-s...

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Abstract

The invention relates to a sub-temperature carburizing heat treatment method for reducing heat treatment deformation of thin-walled gears, comprising the following steps: S1, sub-temperature normalizing in advance; S2, slow shot peening; S3, sub-temperature carburizing: adopting gradient heating to sub-temperature Warm carburizing temperature, sub-temperature carburizing process adopts two-stage carburizing method, the first stage is the strong infiltration stage, and the second stage is the diffusion stage; S4, gradient slow cooling and quenching: first, the thin-walled gear forgings that have completed carburizing treatment Gradient slow cooling to 840-860°C, and keep warm for about 1h; then continue to cool slowly to 815-825°C, and keep warm for about 1h, during which the carbon potential in the furnace is controlled at 0.5±0.05%, and then quenched in polyvinyl alcohol solution; S5, low temperature tempering. The invention can greatly reduce the degree of deformation of the gear workpiece, significantly improve the production pass rate, and at the same time can effectively refine the grains, improve the hardness and strength of the gears, and significantly increase the service life of the gears. In addition, the refined grains can significantly improve The speed of carburizing reduces process time and reduces energy consumption.

Description

technical field [0001] The invention relates to the field of heat treatment, in particular to a sub-temperature carburizing heat treatment method for reducing heat treatment deformation of thin-walled gears. Background technique [0002] High-performance thin-walled gears are common transmission parts in machinery and are widely used in fields such as ships and aerospace vehicles. Due to its complex working environment and long-term exposure to large contact stress, alternating loads and impact loads, the precision and performance requirements of high-performance thin-walled gears are very high. At present, high-performance thin-walled gears mostly adopt the heat treatment method of direct quenching after carburizing with ordinary gas or secondary quenching after carburizing to meet the high hardness and high wear resistance of the surface of thin-walled gears. However, due to the large difference in thickness of various parts of the thin-walled gear, it is very sensitive t...

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C23C8/20C23C8/80C21D1/18C21D1/60C21D9/32C23C8/02
CPCC21D1/18C21D1/60C21D9/32C21D2211/00C23C8/02C23C8/20C23C8/80
Inventor 华林韩星会胡轩庄武豪
Owner WUHAN UNIV OF TECH
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