The roles of internal and external hydrogen in the deformation and fracture processes at the fatigue crack tip zone of metastable austenitic stainless steels
The roles of internal and external hydrogen in the deformation and fracture processes at the fatigue crack tip zone of metastable austenitic stainless steels
复制标题
DOI：
10.1016/j.scriptamat.2018.08.003
复制
发表时间：
2018-12
影响因子：
6
通讯作者：
Yuhei Ogawa;S. Okazaki;O. Takakuwa;H. Matsunaga
中科院分区：
文献类型：
--
作者：
Yuhei Ogawa;S. Okazaki;O. Takakuwa;H. Matsunaga
对两种奥氏体相稳定性不同的亚稳奥氏体不锈钢在氢预充电条件下(内氢)和在气态氢环境中(外氢)进行了疲劳裂纹扩展试验。这些材料在内部氢气条件下表现出比外部氢气条件下特别慢的FCG速率，即使在内部氢气条件下氢浓度要高得多。结果用氢变质塑性变形特征来解释，包括抑制交叉滑移或强化形变孪晶，以及疲劳裂纹尖端周围局部区域氢渗透和应变诱导α‘马氏体的形成顺序。
Fatigue crack growth (FCG) tests were performed with two types of metastable austenitic stainless steels having different austenite phase stabilities under hydrogen-precharged conditions (internal hydrogen) and in gaseous hydrogen environments (external hydrogen). The materials showed a peculiarly slower FCG rate with internal hydrogen than with external hydrogen even though the hydrogen concentration was much higher under the internal hydrogen conditions. The results are interpreted in terms of hydrogen-modified plastic deformation character comprising inhibited cross-slipping or enhanced deformation twinning in combination with the sequence of hydrogen penetration and strain-induced α′ martensite formation in the local region surrounding the fatigue crack tip.