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渗碳钢20X2H4渗碳后渗碳层中存在着大量残留奥氏体,淬火(800℃)后奥氏体仍很多,因此具有较低的硬度及疲劳极限。А.Н.Жиронкин提出淬火前在640°—670℃回火3—8小时以改进这种缺点,这一规程目前仍为国内外很多工厂所采用。本文研究了淬火及回火时渗碳层中的组织转变过程,提出利用残留奥氏体分解时C曲线的特性在其最大转变速度进行回火的新规程(20X2H4经测定为600℃,在此温度透烧1—1.5小时)。本文结果曾在某厂通过生产试验得到了良好的结果。
Carburizing 20X2H4 carburizing carburizing layer there is a large number of retained austenite, austenite after quenching (800 ° C) is still a lot, so has a lower hardness and fatigue limit. А.Н.Жиронкин proposes tempering at 640 ° -670 ° C for 3-8 hours prior to quenching to improve this shortcoming, which is still used by many plants at home and abroad. In this paper, the microstructural transformation in carburized layer during quenching and tempering was studied. A new procedure was proposed to utilize the characteristics of C-curve when tempering retained austenite to be tempered at its maximum transformation rate (20X2H4 was determined to be 600 ° C, Troubby temperature 1-1.5 hours). The results of this paper have been in a factory production test obtained good results.