研究了低碳钢奥氏体氮碳共渗及时效后的渗层组织和相结构。结果表明;经时效后在化合物层的ε母相中析出了γ~1 相,它与母相存在着一定的取向关系:奥氏体淬火层在回火时发生了残余奥氏体的转变及含氮马氏体的分解。据此初步讨论了低碳钢奥氏体氮碳共渗经人工时效后化合物层的时效强化机制及奥氏体淬火层相变对硬度的影响。 The microstructure and phase structure of nitrided carburized austenite and its aging after low carbon steel were studied. The results show that γ ~ 1 phase precipitates in the ε phase of the compound layer after aging, and there is a certain orientation relationship with the parent phase: the retained austenite quenching layer changes during the tempering and Decomposition of nitrogen-containing martensite. Based on this, the mechanism of aging strengthening and the phase transformation of austenite quenched layer on the hardness of low carbon steel after austenitizing nitrocarburizing were preliminarily discussed.