摘要
采用过冷奥氏体在A3-Ar3之间变形工艺,获得平均晶粒尺寸约为 2μm的微细铁素体晶粒组织.过冷奥氏体形变过程的组织演变包括两个阶段:形变前期以形变强化相变铁素体转变为主导;当相变基本完成后,形变后期以铁素体的动态再结晶为主.形变强化相变是一以形核为主的过程,是晶粒细化的主要原因.应变量较小时,铁素体主要沿原奥氏体晶界及晶内变形带等位置形核,随应变量的增加,以铁素体转变前沿畸变区的反复形核为主.
Based on the theory of deformation enhanced transformation, ultra-fine ferrite structure with grain size of about 2 mum was formed during deformation of undercooled austenite between A(3)-Ar-3. Two mechanisms are involved during the deformation process: deformation-enhanced transformation is the dominated factor in the early stage of deformation, while ferrite dynamic recrystallization plays a major role in the final stage after deformation enhanced austenite to ferrite transformation nearly completed. Deformation enhanced transformation is. a nuleation dominated process, which is the main mechanism of grain refinement. Ferrite grains nucleate at austenite grain boundary and, areas with high density defect under small strain, then form repeatedly at areas with high stored energy in front of the ferrite/austenite interface.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2002年第9期897-902,共6页
Acta Metallurgica Sinica
基金
国家重点基础研究发展规划资助项目 G1998061506
关键词
过冷奥氏体
低碳钢
形变强化相变
铁素体动态再结晶
晶粒细化
low carbon steel
deformation-enhariced transformation
ferrite dynamic recrystallization
grain refinement
