Effect of ultrafine grain refinement on hydrogen embrittlement of metastable austenitic stainless steel
Effect of ultrafine grain refinement on hydrogen embrittlement of metastable austenitic stainless steel
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DOI：
10.1016/j.ijhydene.2017.04.249
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发表时间：
2017-06-01
影响因子：
7.2
通讯作者：
Takashima, Kazuki
中科院分区：
文献类型：
--
作者：
Mine, Yoji;Horita, Nobuaki;Takashima, Kazuki
为研究超细晶粒细化对亚稳奥氏体钢氢脆（HE）的影响，对晶粒尺寸在0.1 ~ 0.5 gm范围内的304型钢进行了高压扭转处理试样的微拉伸试验。平均晶粒尺寸< 0.4 μ m的超细晶（UFG）试样在应力应变曲线上表现出有限的均匀伸长率，随后呈现稳态应力状态，这归因于马氏体相变。在不带电状态下，平均晶粒尺寸约为0.5 μ m的UFG试样具有较高的屈服应力和中等的断裂伸长率。在不带电和带电试样中，屈服应力与平均晶粒尺寸之间存在Hall-Petch关系。加氢使摩擦应力增加了40%，但霍尔-佩奇系数没有变化。超细晶粒细化可减轻氢致延性损失。充氢造成的延性损失表现为马氏体相变后的局部变形。这说明氢对马氏体相变的影响不明显，但缩短了随后的局部变形过程。(C) 2017氢能源出版有限责任公司，由爱思唯尔有限公司出版版权所有。
Micro-tensile tests were performed on high-pressure-torsion-processed specimens of type 304 steel with grain sizes in the range of 0.1-0.5 gm to clarify the effect of ultrafine grain refinement on the hydrogen embrittlement (HE) of metastable austenitic steel. The ultrafine-grained (UFG) specimens with average grain sizes < similar to 0.4 mu m exhibited a limited uniform elongation followed by a steady-stress regime in the stress strain curves, which was attributed to a martensitic transformation. A high yield stress and a moderate elongation to failure were attained for the UFG specimens with an average grain size of similar to 0.5 mu m in the uncharged state. Hall-Petch relationships well hold between the yield stress and the average grain size for each uncharged and hydrogen-charged specimen. Hydrogen charging increased the friction stress by 40% but did not change the Hall Petch coefficient. Hydrogen-induced ductility loss was mitigated by ultrafine grain refinement. Ductility loss due to hydrogen charging manifested in the local deformation after a martensitic transformation. This indicates that hydrogen does not significantly affect the martensitic transformation, but shortens the subsequent local deformation process. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.