Nitridation loosening layer heat treatment method capable of controlling ion nitriding formation effectively

Abstract

The invention relates to a nitridation loosening layer heat treatment method capable of controlling ion nitriding formation effectively. The nitridation loosening layer heat treatment method capable of controlling ion nitriding formation effectively comprises the following steps: placing a 42CrMo gear in an ion nitriding furnace, feeding hydrogen to carry out ion sputtering, and continuing feeding nitrogen; after the temperature rises to an oxidizing temperature, closing a nitrogen valve and a hydrogen valve, and feeding air; closing an air valve, opening the nitrogen valve and the hydrogen valve, and carrying out ion nitriding; and after cooling to the room temperature, taking out a sample. The nitridation loosening layer heat treatment method capable of controlling ion nitriding formation effectively has the beneficial effects that an oxidizing treatment process is added before ion nitridation, a compact oxidizing layer is generated on the surface of a material, the surface free energy is increased, loosening is eliminated, the surface hardness and the wear resistance of 42CrMo and the grade accuracy of workpieces of 42CrMo are improved, and nitridation loosening grade is increased to be grade 1 from the original grade 4; the method is simple to operate; a pre-oxidizing medium is air; moreover, the oxidizing temperature is low; and consumption of energy is reduced.

Description

technical field [0001] The invention belongs to metal surface chemical heat treatment technology, and relates to a heat treatment method for efficiently controlling a nitrided loose layer formed by ion nitriding. Background technique [0002] Gears have good comprehensive properties. In order to meet their surface wear resistance, nitriding methods are usually used, mainly including: (1) ion nitriding; (2) salt bath nitriding; (3) gas nitriding, etc. Ion nitriding chemical heat treatment is the earliest developed technology with the widest application range. It has the advantages of uniform nitriding layer, high efficiency, less pollution, short processing time, and small workpiece deformation. It has become an indispensable part of many products. Missing surface strengthening process. [0003] In order to improve the hardness and wear resistance of the gear surface, ion nitriding is usually used as an effective heat treatment method to improve the surface performance of ge...

AI Technical Summary

Problems solved by technology

[0003] In order to improve the hardness and wear resistance of the gear surface, ion nitriding is usually used as an effective heat treatment method to improve the surface performance of gears in China at this stage. The surface hardness and wear resistance of the nitride layer also reduce the surface roughness, which affects the contact fatigue strength of 42CrMo during use

In order to overcome the above defects, multiple rework methods are generally adopted in actual production, but the rework pass rate is low and the processing cost is high.

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