Strengthening an austenitic Fe-Mn steel using nanotwinned austenitic grains

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	Strengthening an austenitic Fe-Mn steel using nanotwinned austenitic grains
	H. T. Wang; N. R. Tao; K. Lu
	2012
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	60 期号:9 页码:4027-4040
摘要	An austenitic Fe-25Mn steel with a low stacking fault energy was subjected to dynamic plastic deformation (DPD) followed by thermal annealing. The as-DPD sample is structurally characterized by a mixed nanostructure consisting of nanosized grains with an average size of 43 nm and bundles of nanoscale twins (with an average twin/matrix lamella thickness of 5 nm), as well as some dislocation structures, which exhibits a high yield strength of about 1470 MPa but a limited tensile ductility. Thermal annealing leads to static recrystallization (SRX) of the nanostructures forming a hierarchical structure of nanotwinned grains embedded in microsized SRX grains, owing to the higher thermal stability of the nanotwinned bundles than that of nanosized grains. With an increasing number of SRX grains the yield strength and ultimate tensile strength drop while the tensile ductility increases. The calculated yield strength of the nanotwinned grains is about 1.5 GPa, much lower than that determined from Hall-Petch strengthening extrapolated to the nanoscale. Work hardening rates of the nanotwin grains, comparable with that of the microsized grains, are higher than that of the original coarse grained sample. The micrograined austenitic Fe-Mn samples strengthened by nanotwinned grains exhibit enhanced strength ductility synergy in comparison with the deformed samples. A combination of a 977 MPa yield strength with a uniform elongation of 21% is achieved in the annealed samples, well above that of the deformed samples. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[wang, h. t.; tao, n. r.; lu, k.] chinese acad sci, shenyang natl lab mat sci, inst met res, shenyang 110016, peoples r china.;lu, k (reprint author), chinese acad sci, shenyang natl lab mat sci, inst met res, wenhua rd 72, shenyang 110016, peoples r china.;lu@imr.ac.cn
关键词	Dynamic Plastic Deformation Austenitic Fe-mn Alloy Nanoscale Twins Mechanical Properties Dynamic Plastic-deformation Stacking-fault Energy Nano-scale Twins Centered-cubic Metals Mechanical-properties Tensile Properties Strain-rate Cu Copper Behavior
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/60284
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	H. T. Wang,N. R. Tao,K. Lu. Strengthening an austenitic Fe-Mn steel using nanotwinned austenitic grains[J]. Acta Materialia,2012,60(9):4027-4040.
APA	H. T. Wang,N. R. Tao,&K. Lu.(2012).Strengthening an austenitic Fe-Mn steel using nanotwinned austenitic grains.Acta Materialia,60(9),4027-4040.
MLA	H. T. Wang,et al."Strengthening an austenitic Fe-Mn steel using nanotwinned austenitic grains".Acta Materialia 60.9(2012):4027-4040.