Fe-13Cr-5Ni马氏体不锈钢在连续加热过程中两相区的奥氏体生长行为

通过光学显微镜、透射电子显微镜、X射线衍射仪以及显微硬度仪研究Fe-13Cr-5Ni马氏体不锈钢在加热过程中的组织转变行为.结果表明,Fe-13Cr-5Ni钢在10℃·s-1的加热速率下,加热至奥氏体单相区,冷却至室温后具有明显的“组织遗传”现象.奥氏体以“针状”形式在马氏体板条界处形核并沿着马氏体板条界长大,与母相间保持Kurdjumov-Sachs(K-S)位向关系.加热至两相区不同温度然后淬火至室温,奥氏体的量随两相区保温温度的升高先增加再减少,650℃时对应室温下残余奥氏体的极大值,并且这一变化趋势与试样显微硬度测试结果所得结论一致.

Austenite growth behavior of Fe-13 Cr-5 Ni martensitic stainless steel under continuous heating

Microstructure transformation of Fe-13Cr-5Ni martensitic stainless steel during continuous heating was investigated by optical microscopy,transmission electronic microscopy,X-ray diffraction,and microhardness testing.Experimental results show that at the heating rate of 10 ℃ · s-1,there is an austenite memory phenomenon after heating to the austenite phase region and quenching to room temperature.Austenite tends to nucleate and grow at lath boundaries in an acicular shape,which has Kurdjumov-Sachs (K-S) orientation relationships with the parent phase.Furthermore,heating to different temperatures in the dual-phase region and quenching to room temperature,the amount of retained austenite in samples firstly increases,gets to the peak at 650 ℃,and then decreases with the increasing of annealing temperature.This trend is coincident with the trend of micro-hardness of the same samples.