奥氏体动态再结晶组织对马氏体相变的影响

Effect of Dynamically Recrystallized Austenite on Martensitic Transformation

采用电阻测量和Ｘ射线衍射分析方法，研究了Ｆｅ－３２Ｎｉ合金高温变形奥氏体动态再结晶组织对马氏体相变开始温度Ｍｓ点和一定深冷处理温度下马氏体生成量的影响。与静态再结晶组织相比，动态再结晶晶粒组织不均匀，其位错亚结构也不均匀。具有位错密度梯度分布的成长中的动态再结晶晶粒晶界附近含有少量的易移动位错，促进马氏体的形核，提高Ｍｓ点及其Ｍｓ点以下较高温度区域转变初期的马氏体生成量，但是对于较低温度区域转变后期的马氏体生成量则无甚影响。

The effects of dynamically recrystallized austenite on the martensite starting temperature, M s, and the volume fraction of mattensite at a given subzero treatment temperature in hot deformed Fe-32Ni alloy was studied by means on measuring of electrical resistance and X-rays diffraction. Deffering from static recrystallization structure, the dynamic recrystallization grains have heterogeneous dynamic substructure. The growing dynamic recrystallization grain contains a few mobile dislocations near the boundary. The mobile dislocations contribute to the nucleation of martensite, and increase the M s temperature and the volume fraction of martensite under higher subzero treatment temperature. But the effect of dynamic recrystallization structure on the volume fraction of martensite under lower subzero treatment temperature has been unobserved.