The dynamic behaviour of a twinning induced plasticity steel
The dynamic behaviour of a twinning induced plasticity steel
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DOI：
10.1016/j.msea.2013.09.081
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发表时间：
2014
期刊：
影响因子：
6.4
通讯作者：
K. Rahman;V. Vorontsov;D. Dye
中科院分区：
文献类型：
--
作者：
K. Rahman;V. Vorontsov;D. Dye
研究了应变速率对 Fe-15Mn-2Al-2Si-0.7C 孪生诱导塑性 (TWIP) 钢的孪生行为和显微组织的影响。除了爆炸测试之外，还使用霍普金森压力棒装置来执行高应变率测试。随着应变率的增加，屈服应力表现出正应变率敏感性。然而，材料的失效应变相对不受影响。变形后显微镜表明，在较高应变率下，变形孪晶不那么丰富。电子背散射衍射还表明，在应变率低于 1000 s−1 时，多个孪生系统被激活，尽管在测试的较高应变率下并没有发生这种情况。发现在较低应变率下测试的材料中存在较大的晶内取向差，这表明在较低应变率下测试的材料中存在相对较大的位错密度。此外，爆炸测试材料中选定的晶粒表现出“波浪形”结构，经确定这不是由于相变造成的。这表明这是由于材料在测试过程中经历的复杂负载造成的。高分辨率透射电子显微镜还表明，经过爆炸测试的材料中存在高密度的固有堆垛层错。
The influence of strain rate on the twinning behaviour and microstructure of an Fe–15Mn–2Al–2Si–0.7C twinning induced plasticity (TWIP) steel has been investigated. A Hopkinson pressure bar setup was used in addition to blast testing to perform the high strain rate testing. The yield stress exhibited a positive strain rate sensitivity with increasing strain rate. However, the failure strain of the material was relatively unaffected. Post-deformation microscopy indicated that deformation twinning was less profuse at higher strain rates. Electron backscatter diffraction also indicated the activation of multiple twin systems at strain rates below 1000 s−1although this did not occur at the higher strain rates tested. A large intragranular misorientation was found to exist in the material tested at lower strain rates indicating a relatively larger dislocation density existing in the material tested at lower strain rates. In addition selected grains in the blast tested material exhibited a ‘wavy’ structure which was determined not to be due to a phase transformation. It is suggested that this was caused by the complex loading experienced by the material during testing. High resolution transmission electron microscopy also indicated a large density of intrinsic stacking faults in the material subjected to blast testing.