Microstructural evolution in adiabatic shear localization in stainless steel

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	Microstructural evolution in adiabatic shear localization in stainless steel
	M. A. Meyers ; Y. B. Xu ; Q. Xue ; M. T. Perez-Prado ; T. R. McNelley
刊名	Acta Materialia
	2003
卷号	51 期号:5 页码:1307-1325
关键词	AISI 304L stainless steel shear bands adiabatic deformation twinning lattice rotation amorphization recrystallization severe plastic-deformation strain-rate deformation dynamic recrystallization grain-size alloy tantalum boundaries titanium behavior copper
ISSN号	1359-6454
中文摘要	Shear bands were generated under prescribed and controlled conditions in an AISI 304L stainless steel (Fe-18%Cr-8%Ni). Hat-shaped specimens were deformed in a Hopkinson bar at strain rates of ca 10(4) s(-1) and shear strains that could be varied between I and 100. Microstructural characterization was performed by electron backscattered diffraction (EBSD) with orientation imaging microscopy (OIM), and transmission electron microscopy (TEM). The shear-band thickness was ca 1-8 mum. This alloy with low-stacking fault energy deforms, at the imposed strain rates (outside of the shear band), by planar dislocations and stacking fault packets, twinning, and occasional martensitic phase transformations at twin-band intersections and regions of high plastic deformation. EBSD reveals gradual lattice rotations of the grains approaching the core of the band. A [110] fiber texture (with the [110] direction perpendicular to both shear direction and shear plane normal) develops both within the shear band and in the adjacent grains. The formation of this texture, under an imposed global simple shear, suggests that rotations take place concurrently with the shearing deformation. This can be explained by compatibility requirements between neighboring deforming regions. EBSD could not reveal the deformation features at large strains because their scale was below the resolution of this technique. TEM reveals a number of features that are interpreted in terms of the mechanisms of deformation and recovery/recrystallization postulated,. They include the observation of grains with sizes in the nanocrystalline domain. The microstructural changes are described by an evolutionary model, leading from the initial grain size of 15 mum to the final submicronic (sub) grain size. Calculations are performed on the rotations of grain boundaries by grain-boundary diffusion, which is three orders of magnitude higher than bulk diffusion at the deformation temperatures. They indicate that the microstructural reorganization can take place within the deformation times of a few milliseconds. There is evidence that the unique microstructure is formed by rotational dynamic recrystallization. An amorphous region within the shear band is also observed and it is proposed that it is formed by a solid-state amorphization process; both the heating and cooling times within the band are extremely low and propitiate the retention of non-equilibrium structures. Published by Elsevier Science Ltd on behalf of Acta Materialia Inc.
原文出处	://WOS:000181677700010
公开日期	2012-04-14
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/35970]
专题	金属研究所_中国科学院金属研究所
推荐引用方式 GB/T 7714	M. A. Meyers,Y. B. Xu,Q. Xue,et al. Microstructural evolution in adiabatic shear localization in stainless steel[J]. Acta Materialia,2003,51(5):1307-1325.
APA	M. A. Meyers,Y. B. Xu,Q. Xue,M. T. Perez-Prado,&T. R. McNelley.(2003).Microstructural evolution in adiabatic shear localization in stainless steel.Acta Materialia,51(5),1307-1325.
MLA	M. A. Meyers,et al."Microstructural evolution in adiabatic shear localization in stainless steel".Acta Materialia 51.5(2003):1307-1325.