配分工艺对低碳Q&P钢中残余奥氏体的影响

Effect of partitioning parameters on the retained austenite in low-carbon Q&P Steel

为提高钢的塑性,在马氏体钢基础上通过Q&P工艺得到一定量的残余奥氏体,达到高强度与高塑性的良好结合.利用扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)和拉伸实验等方法研究了低碳Q&P钢微观组织,在此基础上讨论了配分工艺对残余奥氏体的影响以及残余奥氏体对Q&P钢延伸率的影响.研究结果表明:Q&P钢室温组织主要由马氏体与残余奥氏体组成,其中残余奥氏体形态主要有马氏体板条间薄膜状和晶界处块状两种类型;Q&P钢中残余奥氏体的含量及稳定性与配分温度和配分时间紧密相关.残余奥氏体的存在,是提高Q&P钢塑性的关键.

In order to enhance the plasticity, a certain amount of retained austenite was obtained treated by Q＆P process in martensitic steel, and the combination of excellent strength and plasticity was accomplished. The micro- structure and mechanical properties of the low carbon Q＆P steel were investigated by scan electron microscope （SEM）, transmission electron microscope （TEM）, X-ray diffraction （XRD） and tensile test. The effects of partition process on retained austenite and the effect of retained austenite on elongation of the steel were discussed. The results show that the mierostructure of steel mainly consists of martensite and retained austenite at room tempera- ture, the retained austenite exists in the shape of thin film between lath martensite and lump along grain boundaries, and the stability and content of retained anstenite are largely depended on the partition temperature and partition time. The retained austenite plays a crucial role in enhancing plasticity.