Effect of grain refinement on the hydrogen embrittlement of 304 austenitic stainless steel
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第10期
论文作者：Y.H.Fan B.Zhang J.Q.Wang E.-H.Han W.Ke
文章页码：2213 - 2219
摘 要：The effect of grain size（in the range from 4 μm to 12 μm） on the hydrogen embrittlement（HE） of 304 austenitic stainless steel（ASS） was studied. HE susceptibility result shows that HE resistance increases with grain refinement. Electron backscattered diffraction kernel average misorientation（EBSD-KAM）mapping shows that the strain localization can be mitigated by grain refinement. Hence, strain localization sites which act as highways for hydrogen diffusion and preferred crack initiation sites can be reduced along with grain refinement, leading to a high HE resistance. Meanwhile, grain size shows no influence on the strain induced martensite（SIM） transformation during the hydrogen charging slow strain tensile test（SSRT）. Hence, the SIM formed during hydrogen charging SSRT is not responsible for the different HE resistance of 304 ASSs with various grain sizes. Hydrogen diffusion is supposed to be controlled by a competition between short-circuit diffusion along random grain boundary（RGB） and hydrogen trapping at dislocations, leading to a maximum hydrogen diffusion coefficient in the 304 ASS with an average grain size of 8 μm.
Y.H.Fan1,2,3，B.Zhang1，J.Q.Wang3，E.-H.Han3，W.Ke3
1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences2. School of Materials Science and Engineering, University of Science and Technology of China3. CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences
摘 要：The effect of grain size（in the range from 4 μm to 12 μm） on the hydrogen embrittlement（HE） of 304 austenitic stainless steel（ASS） was studied. HE susceptibility result shows that HE resistance increases with grain refinement. Electron backscattered diffraction kernel average misorientation（EBSD-KAM）mapping shows that the strain localization can be mitigated by grain refinement. Hence, strain localization sites which act as highways for hydrogen diffusion and preferred crack initiation sites can be reduced along with grain refinement, leading to a high HE resistance. Meanwhile, grain size shows no influence on the strain induced martensite（SIM） transformation during the hydrogen charging slow strain tensile test（SSRT）. Hence, the SIM formed during hydrogen charging SSRT is not responsible for the different HE resistance of 304 ASSs with various grain sizes. Hydrogen diffusion is supposed to be controlled by a competition between short-circuit diffusion along random grain boundary（RGB） and hydrogen trapping at dislocations, leading to a maximum hydrogen diffusion coefficient in the 304 ASS with an average grain size of 8 μm.
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