Microstructural evolution and strain hardening behavior during plastic deformation of Fe–12Mn–8Al–0.8C steel
Microstructural evolution and strain hardening behavior during plastic deformation of Fe–12Mn–8Al–0.8C steel
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DOI：
10.1016/j.msea.2013.07.023
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发表时间：
2013-11
期刊：
影响因子：
6.4
通讯作者：
Zhi Qiang Wu;H. Ding;Hua-ying Li;Ming-li Huang;Fu Rong Cao
中科院分区：
文献类型：
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作者：
Zhi Qiang Wu;H. Ding;Hua-ying Li;Ming-li Huang;Fu Rong Cao
研究了Fe-12 Mn-8Al-0.8C钢的组织演变和变形机制。该钢的强度大于900 MPa，塑性约为46%。Fe-12 Mn-8Al-0.8C钢的固溶组织为（α+γ+κ）相的混合组织。在淬火过程中，通过亚稳分解生成κ相碳化物（Fe，Mn）3AlCx。奥氏体在变形初期的变形行为完全取决于位错亚结构的大小，即位错排列和泰勒点阵。随着应变的增加，奥氏体中的位错由泰勒点阵逐渐向高密度位错壁和微带转变。铁素体在低应变下表现出随机分布的位错，在20%应变下表现出高密度的位错缠结。透射电镜观察显示，在30%应变下，有序的κ-碳化物沉淀被滑移带剪切。该钢呈现多阶段的应变硬化行为，这与位错亚结构的变化有关。该钢还表现出高的初始应变硬化速率和高的比强度（约130.5MPa cm ~ 3/g）。
Microstructural evolution and deformation mechanism of a Fe–12Mn–8Al–0.8C steel were investigated. The steel exhibited a good combination of strength over 900 MPa and ductility about 46%. The microstructure of the Fe–12Mn–8Al–0.8C steel in solid solution state was a mixture of the (α+γ+κ) phases. The κ phase carbides ((Fe,Mn)3AlCx) were formed by a spinodal decomposition during quenching. The deformation behavior of the austenite in the early deformation stage was fully determined by the size of the dislocation substructure, namely, dislocations alignment and Taylor lattices. With strain increasing, a gradual transition from Taylor lattices to highly dense dislocation walls and microbands was observed in austenite. Ferrite exhibited randomly distributed dislocations at a low strain and high dense dislocation tangles at a strain of 20%. TEM observations revealed ordered κ-carbide precipitates were sheared by slip bands at a strain of 30%. The present steel presented a multiple-stage strain hardening behavior which was associated with the changes of such dislocation substructures. The steel also exhibited a high initial strain hardening rate and a high specific strength about 130.5 MPa cm3/g.