汽车用Q&P钢中的残留奥氏体

Retained austenite in Q&P steel for automobile

研究了在两相区加热与完全奥氏体区加热Q&P工艺下0.2C-1.51Si-1.84Mn钢中的残留奥氏体。结果表明:两相区加热得到的残留奥氏体量最高达13.39%,完全奥氏体化得到的残留奥氏体量最高达5.23%,配分时间为10 s时,两种加热方式的试样都完成碳配分;两相区加热得到的残留奥氏体以两种形态存在:处于马氏体板条间的薄膜状和位于原奥氏体晶界处的块状,而完全奥氏体化后得到的残留奥氏体以薄膜状存在于马氏体板条间;通过电子背散射衍射(EBSD)发现,残留奥氏体的分布与晶界多少有关。

Retained austemte of Q＆P （Quenching and Partitioning） processed 0.2C-1.51Si-1.84Mn steel heated in dual-phase region and full austenite region were investigated. The results show that the maximum volume fraction of retained austenite is 13.39% when heated in dual-phase region and 5.23% in austenite region. Carbon partitioning completed within 10 s for both heating modes. There are two forms of existence of retained austenite in dual-phase region, the film between lath martensites and the bulk located in original austenite grain boundaries. Retained austenite heated in full austenite region can be acquired in the shape of films distributed within lath martensite. The distribution of retained austenite is related to the mount of grain boundaries by electron backscattered diffraction method.