Self organization of shear bands in stainless steel
- 作者：Xue ; Q. ; Meyers ; M.A. ; Nesterenko ; V.F.
- 关键词：Shear bands ; Dynamic deformation ; Stainless steel ; Self organization
- 刊名：Materials Science and Engineering ; A
- 出版年：2004
- 期刊代码：61_09215093
- 类别：ms
- 出版时间：October 25, 2004
- 卷：384
- 期：1-2
- 页码：35-46
- 文件大小：792 K
摘要
The spatial distribution of shear bands was investigated in 304L stainless steel through the radial collapse of a thick-walled cylinder under high-strain-rate deformation (![]()
border=0 SRC=/images/glyphs/BQ1.GIF>104s−1). The shear-band initiation and propagation were also examined. Self-organization of multiple adiabatic shear bands was observed. The effect of grain size on spacing of shear bands was investigated at four different grain sizes: 30μm, 50μm, 140μm and 280μm. A single crystal with a similar composition was also tested. The experimental results show only a modest variation of shear-band spacing within the investigated grain size range. Three principal mechanisms are considered to be active in initiation: (a) momentum diffusion by stress unloading, (b) perturbation in the stress/strain/temperature fields, (c) microstructural inhomogeneities. The observed shear-band spacing is compared with existing theories; Grady–Kipp and Wright–Ockendon–Molinari theories. These are one-dimensional theories that do not consider the evolution in spacing as the shear bands grow. A discontinuous growth mode for shear localization under periodic perturbation is applied and predicts spacings in good agreement with observations. Self-organized initiation and propagation modes are discussed in relation to the interaction among the nucleus and well-developed shear bands.