低碳硅锰钢I&Q&P处理中C,Mn元素配分综合作用EI北大核心CSCD

采用EMPA,SEM和XRD等手段,研究低碳硅锰钢在双相区保温淬火(I&Q)、双相区保温+奥氏体化+盐浴配分(I&Q&P)和奥氏体化+盐浴配分(Q&P)工艺中的C,Mn元素配分行为及对残余奥氏体的综合作用。结果表明:经I&Q工艺处理后,得到马氏体、铁素体加少量残余奥氏体混合组织,C,Mn在马氏体中出现了富集,并且C富集程度高于Mn;经I&Q&P工艺处理后,C,Mn在板条马氏体中呈现不均匀分布,C的局部富集现象更明显,按C,Mn含量的不同,马氏体可分为"高C高Mn"、"高C低Mn"和"低C低Mn"3种;相比较Q&P工艺中只有C配分作用稳定残余奥氏体,I&Q&P工艺在C,Mn配分综合作用下,能得到更多的残余奥氏体。

Comprehensive Effect of C,Mn Partitioning Behavior on Retained Austenite of Low Carbon Si-Mn Steel in I&Q&P Process

Low carbon Si-Mn steel was processed through the processes of intercritical annealing, quenching (I&Q),or the intercritical annealing,subsequent austenitizing,then quenching partition (I&Q&P)and the austenitizing,quenching partition (Q&P).The C,Mn partitioning behavior and their comprehensive effect on retained austenite were studied by means of electron microprobe analysis (EMPA),field emission scanning electron microscopy (SEM)and X-ray diffraction (XRD).The results show that the microstructure of low carbon Si-Mn steel is composed of martensite,ferrite and some retained austenite after treated by I&Q process.C,Mn in martensite of low carbon Si-Mn steel is enriched,and C enrichment level is higher than Mn level.After treated by I&Q&P process,C,Mn of steel exhibits nonuniform distribution in lath martensite,and the local enrichment of C is more obvious.The martensite can be divided into three forms of "high C high Mn","high C low Mn"and"low C low Mn"according to the different C and Mn contents .The content of retained austenite of the steel treated by I&Q&P process is higher under the comprehensive effect of C,Mn partitioning than that of Q&P process which is stabilized only by C partitioning.