低碳钢临界奥氏体区的变形行为

在Gleeble-3500型热模拟试验机上对Q235钢进行了单向压缩试验，研究了不同温度下低碳钢的变形特征以及形变诱导铁素体的演变行为和在保温过程中的变化。结果表明：降低变形温度有利于低碳钢的组织细化，但变形温度低于Ar3时，得到混晶组织，并使珠光体成务状分布；随着变形的进行，形变诱导铁素体首先在晶界形核，然后在相界上反复形核；铁素体数量随着应变量的增加而增加，但存在一个极限值；应变量较高时，将会发生铁素体的动态回复和再结晶；形变诱导铁素体在变形后的保温过程中发生了逆相变并伴随着铁素体晶粒的粗化。

Deformation Behavior of Low Carbon Steel

Hot compression tests of Q235 steel were performed using Gleeble-3500 tester. The deformation characters and the evolution of deformation induced transformation ferrite of low carbon steel were studied. The ferrite grain became finer as the deformation temperature was decreased, but mixed grain microstructure appeared when the deformation temperature was below Ar3. As the deformation progressed, ferrite nucleated first at austenite boundaries and then at the ferrite/austenite interface. The ferrite fraction increased as the strain increased up to a limit. The dynamic recrystallization of ferrite occurred at high strain. Isothermal holding after deformation led to an inverse transformation of ferrite and the corsing phenomenon of ferrite grain was observed.