Strain rate effects on tensile deformation behaviors for Fe–22Mn–0.6C–(1.5Al) twinning-induced plasticity steel
Strain rate effects on tensile deformation behaviors for Fe–22Mn–0.6C–(1.5Al) twinning-induced plasticity steel
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DOI：
10.1016/j.msea.2014.04.043
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发表时间：
2014-06
期刊：
影响因子：
6.4
通讯作者：
H. K. Yang;Z. Zhang;F. Dong;Q. Duan;Z. F. Zhang
中科院分区：
文献类型：
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作者：
H. K. Yang;Z. Zhang;F. Dong;Q. Duan;Z. F. Zhang
在本研究中，研究了应变速率对 Fe-22Mn-0.6C-(1.5Al) (wt%) 孪晶诱导塑性 (TWIP) 钢拉伸变形行为的影响。实验结果表明，加工硬化指数（n）、极限拉伸强度（σu）和均匀伸长率（δu）随着应变速率的增加（从10−4到100s−1）而降低。这种现象表现出负应变率敏感性（NSRS），并且观察到添加铝的FeMnC TWIP钢的应变率敏感性值（m）更高。为了深入了解铝的这种敏感性及其后续影响，本研究重点关注变形孪晶，并从分数（F）、厚度（t）和间距（s）方面对其影响进行了比较研究。此外，还提出了孪晶边界影响区（TBAZ）模型，其中较高应变率之间的关系直接适用于基体和变形孪晶之间界面的减少。这些结果表明，在高应变率下可以容纳更少的固着位错，从而削弱加工硬化能力。最后，进行模型计算来验证研究结果，其中观察到 FeMnC-Al 中的 TBAZ 区域分数高于 FeMnC，这对应于应变率敏感性的增加。
In this study, the effect of strain rate on the tensile deformation behavior of Fe–22Mn–0.6C–(1.5Al) (wt%) twinning-induced plasticity (TWIP) steel was investigated. The experimental results indicated that the work hardening exponent (n), ultimate tensile strength (σu) and the uniform elongation (δu) decreased with increasing strain rates (from 10−4to 100s−1). This phenomenon exhibited negative strain rate sensitivity (NSRS), and the strain rate sensitivity value (m) was observed to be higher in the aluminum added FeMnC TWIP steel. In order to gain an in-depth understanding of this sensitivity and the subsequent effect of aluminum, the present research focused on the deformation twins and conducted comparative studies on their influence in terms of fractions (F), thickness (t) and spacing (s). Additionally, a twin boundary affected zone (TBAZ) model was proposed, where the relation between higher strain rates were directly applicable to the reduction of interfaces between the matrix and deformation twins. These result indicated that fewer sessile dislocations could be accommodated at high strain rates, thus weakening the work hardening ability. Finally, model calculations were performed to validate the findings, where TBAZ region fractions in FeMnC–Al were observed to be higher than that in FeMnC, corresponding to the increased strain rate sensitivity.