Flow stress analysis of TWIP steel via the XRD measurement of dislocation density
Flow stress analysis of TWIP steel via the XRD measurement of dislocation density
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DOI：
10.1016/j.msea.2010.01.033
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发表时间：
2010-04-25
期刊：
影响因子：
6.4
通讯作者：
Monir-Vaghefi, S. M.
中科院分区：
文献类型：
--
作者：
Dini, G.;Ueji, R.;Monir-Vaghefi, S. M.
在这项研究中，通过 X 射线衍射 (XRD) 测量计算了拉伸应变孪晶诱导塑性 (TWIP) 钢中的位错积累率，并与其他面心立方金属和合金进行了比较。结果表明，XRD 技术是估计位错密度的替代方法。此外，对晶粒尺寸约为18μm的Fe-31Mn-3Al-3Si TWIP钢的流变应力分析表明，除了位错相互作用对流变应力的直接影响外，还需要另一种强化机制来描述流变行为。因此，由于机械孪晶的形成而产生的强化贡献被认为是位错平均自由程的减少。有趣的是，由位错相互作用和机械孪生（即动态霍尔-佩奇效应）引起的动态微观结构细化的强化效应组成的估计流动应力方程与Ludwigson针对低SFE材料提出的实验数据和方程非常一致。 (C) 2010 Elsevier B.V. 保留所有权利。
In this study, the rate of dislocation accumulation in the tensile strained twinning induced plasticity (TWIP) steel was calculated via the X-ray diffraction (XRD) measurements and compared with other fcc metals and alloys. The results indicated that the XRD technique is an alternative method to estimate the dislocation density. Moreover, flow stress analysis of Fe-31Mn-3Al-3Si TWIP steel with the grain size of about 18 mu m indicated that, beside a direct effect of the dislocation interactions on the flow stress, another strengthening mechanism is also required to describe the flow behavior. For this reason, the strengthening contribution due to the formation of mechanical twins was considered as a reduction of dislocation mean free path. Interestingly, the estimated flow stress equation consisting of the strengthening effects of both dislocation interactions and dynamic microstructure refinement due to mechanical twinning (i.e., the dynamic Hall-Petch effect) are in good agreement with the experimental data and equation proposed by Ludwigson for low SFE materials. (C) 2010 Elsevier B.V. All rights reserved.