中国物理B ›› 2014, Vol. 23 ›› Issue (2): 26104-026104.doi: 10.1088/1674-1056/23/2/026104
• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇 下一篇
孙世成a b, 孙贵训a, 江忠浩a, 季长涛b, 刘家安a, 连建设a
Sun Shi-Cheng (孙世成)a b, Sun Gui-Xun (孙贵训)a, Jiang Zhong-Hao (江忠浩)a, Ji Chang-Tao (季长涛)b, Liu Jia-An (刘家安)a, Lian Jian-She (连建设)a
摘要: Effects of cold rolling deformation on the microstructure, hardness, and creep behavior of high nitrogen austenitic stainless steel (HNASS) are investigated. Microstructure characterization shows that 70% cold rolling deformation results in significant refinement of the microstructure of this steel, with its average twin thickness reducing from 6.4 μm to 14 nm. Nanoindentation tests at different strain rates demonstrate that the hardness of the steel with nano-scale twins (nt-HNASS) is about 2 times as high as that of steel with micro-scale twins (mt-HNASS). The hardness of nt-HNASS exhibits a pronounced strain rate dependence with a strain rate sensitivity (m value) of 0.0319, which is far higher than that of mt-HNASS (m=0.0029). nt-HNASS shows more significant load plateaus and a higher creep rate than mt-HNASS. Analysis reveals that higher hardness and larger m value of nt-HNASS arise from stronger strain hardening role, which is caused by the higher storage rate of dislocations and the interactions between dislocations and high density twins. The more significant load plateaus and higher creep rates of nt-HNASS are due to the rapid relaxation of the dislocation structures generated during loading.
中图分类号: (Metals and alloys)