文献类型：期刊文献

英文题名：Grain refinement mechanism of multiple laser shock processing impacts on ANSI 304 stainless steel

作者：Lu, J. Z.[1];Luo, K. Y.[1];Zhang, Y. K.[1];Sun, G. F.[1];Gu, Y. Y.[1];Zhou, J. Z.[1];Ren, X. D.[1];Zhang, X. C.[2];Zhang, L. F.[3];Chen, K. M.[4];Cui, C. Y.[1];Jiang, Y. F.[1];Feng, A. X.[1];Zhang, L.[1]

机构：[1]Jiangsu Univ, Sch Mech Engn, Zhenjiang 212013, Peoples R China;[2]E China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China;[3]Henan Univ Sci & Technol, Sch Mat Sci & Engn, Luoyang 471003, Peoples R China;[4]Jiangsu Univ, Sch Mat Sci & Engn, Zhenjiang 212013, Peoples R China

年份：2010

卷号：58

期号：16

起止页码：5354

外文期刊名：ACTA MATERIALIA

收录：;EI(收录号：20103213145300);WOS:【SCI-EXPANDED(收录号:WOS:000281318900013)】；

基金：Financial support from the National Natural Science Foundation of China (nos. 50705038 and 50735001), Natural Science Foundation of Jiangsu Province of China (nos. BK2009219 and 2007512), Doctoral Foundation of Ministry of Education (no. 200802990004) and the Innovation Program of Graduated Student of Jiangsu Province (no. xm06-45) is acknowledged.

语种：英文

外文关键词：Laser shock processing; 304 Stainless steel; Plastic deformation; Grain refinement; Mechanical twinning

摘要：Micro-structural evolution and grain refinement in ANSI 304 stainless steel subjected to multiple laser shock processing (LSP) impacts were investigated by means of cross-sectional optical microscopy and transmission electron microscopy observations. The plastic strain-induced grain refinement mechanism of the face-centered cubic (fcc) materials with very low stacking fault energy was identified. The micro-structure was obviously refined due to the ultra-high plastic strain induced by multiple LSP impacts. The minimum grain size in the top surface was about 50-200 nm. Multidirectional mechanical twin matrix (MT)-MT intersections led to grain subdivision at the top surface during multiple LSP impacts. Furthermore, a novel structure with submicron triangular blocks was found at the top surface subjected to three LSP impacts. The grain refinement process along the depth direction after multiple LSP impacts can be described as follows: (i) formation of planar dislocation arrays (PDAs) and stacking faults along multiple directions due to the pile up of dislocation lines; (ii) formation of submicron triangular blocks (or irregularly shaped blocks) by the intersection of MT-MT (or MT-PDA or PDA-PDA) along multiple directions; (iii) transformation of MTs into subgrain boundaries; (iv) evolution by continuous dynamic recrystallization of subgrain boundaries to refined grain boundaries. The experimental results and analyses indicate that a high strain with an ultra-high strain rate play a crucial role in the grain refinement process of fcc materials subjected to multiple LSP impacts. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.