Influence of Al on the temperature dependence of strain hardening behavior and glide planarity in Fe-Cr-Ni-Mn-C austenitic stainless steels
Influence of Al on the temperature dependence of strain hardening behavior and glide planarity in Fe-Cr-Ni-Mn-C austenitic stainless steels
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DOI：
10.1016/j.msea.2015.10.005
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发表时间：
2016-01-01
期刊：
影响因子：
6.4
通讯作者：
Mola, Javad
中科院分区：
文献类型：
--
作者：
Rahimi, Reza;Ullrich, Christiane;Mola, Javad
对两种成分为Fe-17Cr-9Ni-6Mn-0.4C-(0和4)Al(质量分数)的奥氏体不锈钢在-196℃~200℃范围内进行了拉伸试验，研究了Al对应变硬化行为、拉伸性能和变形组织的温度依赖性的影响。两种合金在高变形温度下的应变硬化表现为低应力下的近线性硬化和高应力下的非线性硬化。较低的拉伸温度导致了初始近线性硬化区域的延长。在比不含铝合金更低的温度(-100摄氏度比-40摄氏度)下进行近线性硬化，直到建立颈缩。这与含铝合金中较高的滑动波动度有关。形变孪晶是形变组织中滑移平面性最明显的特征。在所研究的温度范围内，两种钢的拉伸延伸率均达到最大值。峰值伸长温度几乎与发生近线性硬化直至颈缩的温度完全一致，因此对于含铝合金来说，这一温度较低。在低于峰值伸长温度时的塑性损失是由于在变形孪晶的交叉处出现了一小部分变形诱发的α‘。结果表明，添加Al后，奥氏体相的稳定性增强，这与已报道的Al的层错能升高效应相一致。(C)2015爱思唯尔B.V.保留所有权利。
Two austenitic stainless steels of compositions Fe-17Cr-9Ni-6Mn-0.4C-(0 and 4)Al (mass-%) were tensile tested at temperatures between -196 degrees C and 200 degrees C. The influence of Al on the temperature dependence of the strain hardening behavior, tensile properties, and deformed microstructures was subsequently studied. For both alloys, the strain hardening at high deformation temperatures was characterized by near-linear hardening at low stresses and transition to a regime of non-linear hardening at higher stresses. Lower tensile temperatures resulted in the extension of the initial near-linear regime of hardening. Near-linear hardening until necking was established at a lower temperature for the Al-containing alloy than for the Al-free alloy (-100 degrees C vs -40 degrees C). This was correlated with a higher glide waviness in the Al-containing alloy. Deformation twinning was the most obvious feature of glide planarity in the deformed microstructures. Tensile elongation of both steels showed a maximum within the temperature range studied. The peak elongation temperature almost exactly coincided with the temperature at which near-linear hardening until necking occurred and was therefore lower for the Al-containing alloy. The loss of ductility at temperatures below the peak elongation temperature was attributed to the occurrence of a small fraction of deformation-induced alpha' at intersections of deformation twins. In agreement with the reported stacking fault energy-raising effect of Al, results indicated an increased stability of austenite upon Al addition. (C) 2015 Elsevier B.V. All rights reserved.