Fe-3%Si合金热变形过程中的组织演变

Microstructural evolution of Fe-3%Si alloy during hot deformation

利用Gleeble-1500热模拟实验机对Fe-3%Si合金进行1173K、0.01s-1条件下的压缩变形,借助EBSD分析了不同应变量下晶界与热变形组织特征演变。发现晶体旋转动态再结晶机制与几何动态再结晶机制共同控制了动态再结晶过程:在小应变量阶段,晶体旋转的不均匀性使晶界附近区域优先形成完善亚晶,而晶粒内部呈现不完善的亚晶;随应变量增大,晶界附近区域取向差增加,小角晶界逐渐演变为大角晶界;在大应变量阶段,原始晶界附近区域形成的大角晶界相互接触,最终通过几何动态再结晶机制实现通体动态再结晶。

Compression test of Fe-3%Si alloy was carried out at 1173K and 0.01s^-1 by Gleeble-1500 simulation machine.The evolution of grain boundary and microstructure at various strains was analyzed by means of EBSD technique.It was shown that both mechanisms,lattice rotation dynamic recrystallization and geometric dynamic recrystallization,control the dynamic recrystallization process of Fe-3% Si alloy.Well-developed sub-grains formed in the vicinity of original grain boundary by progressive lattice rotation at small strain.With the strain increasing,the misorientation of low-angle grain boundaries increased so that some high-angle boundaries formed.At enough large strain,the recrystallized grains near initial grain boundary contacted with each other,and led to complete dynamic recrystallization.