摘要
对退火后Fe-Mn-C-Al系孪生诱发塑性(TWIP)钢进行不同变形量(1.5%,4.0%,39.0%,47.0%,52.0%,62.0%)的室温单向拉伸试验,研究了该钢在拉伸过程中的加工硬化行为及显微组织演变。结果表明:随着变形量增加,TWIP钢奥氏体晶粒内部开始出现形变孪晶,且密度不断提高,变形机制由位错滑移变为孪生和位错共同作用,拉伸断口呈典型韧性断裂特征;试验钢弹性变形阶段短暂,无明显的屈服平台和物理屈服点,塑性变形阶段存在长加工硬化过程;试验钢的加工硬化率先随真应变增加而急剧下降,此时加工硬化机制以位错强化为主,随着真应变继续增加,加工硬化率增加,在应变为0.55时达到峰值,后趋于平缓,加工硬化机制主要为孪晶强化。
The annealed Fe-Mn-C-Al twinning induced plasticity(TWIP)steel was subjected to unidirectional tensile test at room temperature with different deformation amounts(1.5%,4.0%,39.0%,47.0%,52.0%,62.0%).The workhardening behavior and microstructure evolution of the steel were studied.The results show that with the increase of deformation amount,deformation twins began to appear in the austenitic grain of the test steel,and the density increased continuously.The deformation mechanism changed from dislocation slip to the interaction of twin and dislocation,and the tensile fracture showed typical ductile fracture characteristics.The elastic deformation stage of the test steel was short,there was no obvious yield platform and physical yield point,and there was a long work hardening process in the plastic deformation stage.The work hardening rate of the test steel first decreased sharply with the increase of true strain,and the work hardening mechanism was mainly dislocation strengthening.With the further increase of true strain,the work hardening rate increased gradually,reached a peak value at true strain of 0.55,and then tended to be stable,and the main mechanism of work hardening was twin strengthening.
作者
彭松
王荣吉
周童
王志宇
毛亮
PENG Song;WANG Rongji;ZHOU Tong;WANG Zhiyu;MAO Liang(School of Mechanical and Electrical Engineering,Central South University of Forestry and Technology,Changsha 410004,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2024年第2期68-73,共6页
Materials For Mechanical Engineering
基金
湖南省教育厅优秀青年资助项目(18B193)。
