材料期刊网

利用Formastor-FⅡ全自动相变仪模拟研究了一种Fe-0.24C-0.3Si-1.0Mn-0.56Cr-0.17Mo（质量分数，%）钢在冷却过程中的碳配分行为及其对马氏体和残余奥氏体的影响，用扫描电镜、透射电镜进行微观组织表征，用X射线衍射法和电子背散射衍射法测定残余奥氏体体积分数。结果表明，试验钢分别经末段慢冷和直接快冷工艺冷却后均获得马氏体＋残余奥氏体两相组织，其中直接快冷工艺所得马氏体相对杂乱，尺寸较小，残余奥氏体体积分数较少；而末段慢冷工艺所得马氏体板条较长，且发生了碳的配分，残余奥氏体体积分数较多，以薄膜状分布在马氏体板条间，板条内部含有高密度位错。

The carbon partitioning behavior and its effect on martensite and retained austenite of Fe-0.24C-0.3Si-1.0Mn-0.56Cr-0.17Mo(mass prcent,%)steel during coolling processes after hot punching were investigated by using fully auto-dilatometer Formastor-FⅡ. The microstructure characterization was carried out by means of scanning electron microsco-py and transmission electron microscopy,and the austenite fraction measurement was determined by X-ray diffraction and electron back scattered diffraction. The results show that martensite and retained austenite were obtained in different cooling processes after hot punching. Using direct fast cooling process after hot punching,the martensite lath was rela-tively confused and shorter and the amount of retained austenite was less. While using slow cooling process in the end, the martensite lath was longer. It’s found that the carbon partition occurred in the slow cooling process. More retained austenite distributed among the martensite lath and formed thin films. High density dislocation distributed within mar-tensite lath.