提高渗碳淬火齿轮硬度的后处理工艺  

Post-treatment process for improving hardness of carburized and quenched gears

作　　者：赵少甫 许鸿翔 王红伟 李子岩 陈岩 李纪强 陈生超 戎泽玉 Zhao Shaofu;Xu Hongxiang;Wang Hongwei;Li Ziyan;Chen Yan;Li Jiqiang;Chen Shengchao;Rong Zeyu(Zhengzhou Research Institute of Mechanical Engineering Co.,Ltd,Zhengzhou Henan 450001,China)

机构地区：[1]郑州机械研究所有限公司,河南郑州450001

出　　处：《金属热处理》2022年第10期129-134,共6页Heat Treatment of Metals

基　　金：国家重点研发计划(2018YFB2001900)。

摘　　要：研究了20Cr2Ni4A钢渗碳淬火齿轮在低温回火后硬度较低时进行后冷处理和后低温回火处理对表面硬度、有效硬化层深度及心部硬度的影响。结果表明,20Cr2Ni4A钢在渗碳淬火低温回火后的残留奥氏体稳定化现象并不明显,此时进行冷处理仍能提高工件硬度,而当残留奥氏体较多时具有低温回火二次硬化现象,提高低温回火温度也能提高表面硬度。据此可采用后冷处理和后低温回火工艺提高硬度,代替常规的重新高温回火+渗碳淬火+低温回火的返工工艺。后冷处理温度可根据Mf点确定,对于渗碳后高温回火并重新加热淬火和低温回火工艺,Ms和Mf点不能按常规方法计算,可根据残留奥氏体含量进行估算。Effect of post-subzero treatment and post-low temperature tempering on surface hardness, CHD and core hardness of 20 Cr2 Ni4 A steel gear when the hardness was low after carburizing and quenching and low temperature tempering was studied. The results show that the stabilization of retained austenite in the 20 Cr2 Ni4 A steel after carburizing, quenching and low temperature tempering is not obvious, thus subzero treatment can still improve the hardness of the workpiece. A secondary hardening phenomenon after low temperture tempering appears when the 20 Cr2 Ni4 A steel contains more retained austenite, thus increasing the low temperature tempering temperature can also increase the surface hardness. Therefore, the post-subzero and post-low temperature tempering treatment process can be used to improve the hardness, instead of the conventional rework process of re-high temperature tempering, carburizing and quenching and low temperature tempering. The post-subzero treatment temperature shall be determined according to the Mf point. For the process of carburizing, high temperature tempering, re-heating and quenching and low temperature tempering, the Ms and Mf cannot be calculated according to the traditional method, however, it can be estimated by the retained austenite content.

关 键 词：渗碳淬火 硬度 残留奥氏体 MF 冷处理 二次硬化 

分 类 号：TG156.8[金属学及工艺—热处理]