A critical assessment of deformation twinning and epsilon martensite formation in austenitic alloys during complex forming operations
A critical assessment of deformation twinning and epsilon martensite formation in austenitic alloys during complex forming operations
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DOI：
10.1016/j.matchar.2018.09.003
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发表时间：
2018-11
影响因子：
4.7
通讯作者：
M. Weiss;K. Mester;A. Taylor;N. Stanford
中科院分区：
文献类型：
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作者：
M. Weiss;K. Mester;A. Taylor;N. Stanford
研究了机械孪晶和ε-马氏体形成对奥氏体合金在复杂应变路径下成形性的影响。研究的合金之一通过变形孪晶和滑移（TSTK）变形，并且该合金用两种晶粒尺寸进行检查。第二种合金表现出三种同时存在的变形模式（滑移、TdR和ε-马氏体TRIP）。与类似合金相比，TTRIP/TRIP合金显示出显著降低的可成形性，这归因于应变局部化的早期发展和应力诱导的ε-马氏体形成的组合。如果相变产物是ε-马氏体，则在高成形性钢板中TRIP效应可能是不理想的。显微组织检查表明，不同的应变路径发展不同的孪晶体积分数。塑性模型表明，这是不同应变路径中纹理发展差异的结果。在滑移、TdR和TRIP可以同时操作的微结构中，激活孪生的应力不受变得有效的附加变形模式的影响。
The effect of mechanical twinning and ε-martensite formation on the formability of austenitic alloys in complex strain pathways has been examined. One of the alloys studied deformed by deformation twinning and slip (TWIP), and this alloy was examined with two grain sizes. The second alloy showed three concurrent deformation modes (slip, TWIP and ε-martensite TRIP). The TWIP/TRIP alloy showed a markedly reduced formability compared to similar alloys, and this has been attributed to a combination of the early development of strain localizations, and the stress-induced formation of ε-martensite. It is suggested that the TRIP effect may not be desirable in high formability sheet steels if the transformation product is ε-martensite. Microstructural examination revealed that the different strain paths develop different twin volume fractions. Plasticity modelling has shown this to be the result of differences in texture development in the different strain paths. In microstructures where slip, TWIP and TRIP can operate concurrently, the stress to activate twinning is unaffected by the additional deformation mode becoming operative.