热处理工艺对40Cr组织和性能的影响

The Influence of Heat Treatment Process on the Micro-structure and Mechanical Properties of 40Cr

研究40Cr钢在不同热处理工艺下的组织和耐磨性。结果表明:40Cr最佳的热处理工艺为经850℃保温60 min正火,试样硬度约为200 HBS,正火后组织为索氏体;再经780℃淬火保温30 min后水冷,试样硬度约为52 HRC,淬火所得组织为板条状马氏体和针状马氏体;最后经200℃低温回火后,试样硬度维持在50 HRC以上,所得组织为回火马氏体;经淬火及回火后,试样耐磨性得到显著提高。

This article introduces the micro-structure and wear resistance of 40Cr steel under different heat treatment processes. The optimal procedures of heat treatment is as follows, after air-cooled normalizing at 850 ℃ for 60 minutes, the hardness value of the sample is approximately 200HBS with the micro-structure of sorbite. Then the sample reaches the hardness of 52 HRC with the micro-structure of lath and needle-type martensite after quenching at 780 ℃ for 30 minutes. Final heat-treatment of low tempering at 200℃ for 60 minutes ended in the micro-structure of tempered martensite while the sample＇s hardness remains above 50 HRC. Moreover, the wear resistance of 40Cr steel increases dramatically after quenching and tempering.