马氏体岛的体积分数、形状及强度对粒状组织钢力学性能的影响

INFLUENCES OF VOLUME FRACTION,SHAPE AND STRENGTH OF MARTENSITE ISLANDS ON MECHANICAL PROPERTIES OF GRANULAR STRUCTURE STEELS

考虑马氏体岛的塑性变形,采用Eshelby等效夹杂模型对粒状组织钢单向应力状态下的弹塑性变形行为进行了数值模拟.结果表明:粒状组织钢的屈服强度及马氏体处于弹性变形阶段的加工硬化率均随马氏体岛的体积分数的增加而增加,并呈一定的非线性;马氏体岛的形状对粒状组织钢均匀变形阶段的应力-应变曲线影响较小;马氏体岛的强度对粒状组织钢的屈服强度影响不大;马氏体岛的体积分数越低,马氏体岛越难发生塑性变形.

The uniaxial load flow behavior of granular structure steels was predicted by Eshelby equivalent inclusion model incorporating the plastic deformation of martensite islands. The result shows that the yield strength and work hardening ratio of granular structure steels increase nonlinearly with the increase in the volume fraction of martensite islands before martensite yielding. The morphology of martesite island plays a little role in stress-train curves of homogeneous deformation. The strength of martensite island has little influence on the yield strength of granular structure and martensite island is harder to deform plastically as martensite has lower volume fraction.