Effects of Al on microstructure and tensile properties of C-bearing high Mn TWIP steel
Effects of Al on microstructure and tensile properties of C-bearing high Mn TWIP steel
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DOI：
10.1016/j.actamat.2011.12.004
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发表时间：
2012-02-01
期刊：
影响因子：
9.4
通讯作者：
Lee, Y-K.
中科院分区：
文献类型：
--
作者：
Jin, J-E.;Lee, Y-K.
系统研究了Al对Fe-18 Mn-0.6C-（0-2）Al孪晶诱导塑性钢的显微组织、层错能、拉伸性能和断口形貌的影响。Al的加入抑制了热轧后冷却过程中铁素体的析出。堆垛层错能线性增加，斜率为7.8mJ m（-2）/1 wt.% Al的加入增加了屈服应力、断面收缩率、均匀（e（u））和均匀后（e（pu））伸长率，同时降低了应变硬化和动态应变时效（DSA）的量和速率。特别地，虽然不含Al的TdR钢的e（pu）几乎为零，但通过添加2 wt.%铝，这是与双相和TRIP钢具有类似的抗拉强度为780 MPa。为了阐明含碳Td 3钢e（pu）值低和Al的加入使e（pu）值延长的原因，测定了两种含碳Td 3钢（Al含量分别为0和2 wt.%）的表观绝对应变速率敏感性m = d σ/d In（pu）在室温下进行了研究。这两种马氏体钢在颈缩前的大应变（ε = 0.4）下具有负应变率敏感性。然而，Al的加入增加了应变速率敏感性，导致改善的e（PU），因为减少DSA的活性和C在奥氏体中的扩散率降低。(C)2011 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The effects of Al on microstructure, stacking fault energy, tensile properties and fractured surface in Fe-18Mn-0.6C-(0-2)Al twinning-induced plasticity (TWIP) steels were systemically investigated. The Al addition suppressed the cementite precipitation during cooling after hot-rolling. The stacking-fault energy was linearly raised with a constant slope of 7.8 mJ m(-2) per 1 wt.% Al. The Al addition increased the yield stress, reduction in area, uniform (e(u)), and post-uniform (e(pu)) elongations, while it decreased the amount and rate of strain hardening and dynamic strain aging (DSA). In particular, although the e(pu) of the TWIP steel without Al was almost zero, it was improved up to similar to 7% by addition of 2 wt.% Al, which was comparable with those of dual phase and TRIP steels with a similar tensile strength of 780 MPa. In order to elucidate the reasons for the poor e(pu) in C-bearing TWIP steel and for the prolonged e(pu) by Al addition, the apparent absolute strain-rate sensitivity m = d sigma/d In (epsilon) over dot of two TWIP steels with different Al concentrations of 0 and 2 wt.% was investigated at room temperature. Both TWIP steels had negative strain-rate sensitivity at a large strain (epsilon = 0.4) of just before necking. However, the Al addition increased the strain-rate sensitivity, resulting in improved e(pu) because of reduced DSA by decreases in both activity and diffusivity of C in austenite. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.