A kind of carbonitriding heat treatment process method

Abstract

The invention discloses a carbonitriding heat treatment technique under a new atmosphere. The technique comprises the following steps that (a), a multi-purpose chamber furnace suitable for carburizing treatment is selected; (b), a nitrogen, methyl alcohol, ammonia gas and dimethylmethane carburizing medium is adopted, and an oxygen probe is adopted to control the carbon potential, so that control over the carbon potential of the atmosphere in the furnace is achieved; (c), according to a charging mode, charging layers are chosen according to the heights of workpieces, and gaps are kept between the workpieces of each layer to guarantee the uniformity of infiltration layers; (d), according to technological parameters, the carbonitriding temperature is 815 DEG C-825 DEG C, the carbon potential is 1.20%-1.30%, and strong infiltration is conducted for 3 h-3.5 h; in the diffusion period, the temperature is 815 DEG C-825 DEG C, the carbon potential is 1.10%-1.20%, and diffusion is conducted for 3 h-3.5 h; KR-218 fast bright quenching oil is used for quenching, and cooling is conducted for 8 min-15min; and air cooling is conducted after tempering; and (e), steel foil is used for carbon determination during strong infiltration of each furnace. According to the carbonitriding heat treatment technique under the new atmosphere, a carbonitriding layer with a certain depth can be obtained in a relatively short time, and higher hardness is achieved.

Description

technical field [0001] The invention belongs to the technical field of heat treatment, and relates to a carbonitriding heat treatment process, in particular to a carbonitriding heat treatment process for a high-carbon chromium bearing steel GCr15 bearing ring. The present invention is only applicable to the carbonitriding heat treatment process of the inner and outer rings of the bearing with the diameter of the bearing ring not greater than 120 mm and the effective wall thickness not less than 2.0 mm. The invention is applicable to a box-type multipurpose furnace, and carries out carbonitriding treatment on bearing parts. Background technique [0002] As we all know, GCr15 is the most widely used high-carbon chromium bearing steel in the bearing industry. Some domestic and foreign well-known brands of small and medium-sized precision bearings or bearings used in special working conditions mostly use this material and adopt special heat treatment processes. For example, car...

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Problems solved by technology

[0003] In order to give full play to the potential of the existing high-carbon chromium bearing steel GCr15, solve the problems of long cycle and poor economy of the conventional carbonitriding heat treatment process, and the defects of non-horse structure, network structure and coarse carbide, The invention provides a carbonitriding heat treatment process, which makes the treated bearing ring have higher hardness, higher wear resistance and longer life, and improves the reliability of the bearing operation.

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