Grain-boundary diffusion and precipitate trapping of hydrogen in ultrafine-grained austenitic stainless steels processed by high-pressure torsion
Grain-boundary diffusion and precipitate trapping of hydrogen in ultrafine-grained austenitic stainless steels processed by high-pressure torsion
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DOI：
10.1016/j.msea.2011.07.031
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发表时间：
2011-10-25
期刊：
影响因子：
6.4
通讯作者：
Horita, Zenji
中科院分区：
文献类型：
--
作者：
Mine, Yoji;Tachibana, Kazutaka;Horita, Zenji
本文研究了两种经高压扭转（HPT）和后续退火处理的超细晶奥氏体不锈钢中晶界和析出物对室温氢输运的影响。含Ti的Fe-25 Ni-15 Cr（以质量%计）合金和Fe-25 Cr-20 Ni合金中的晶粒通过HPT处理分别细化至近似150和近似85 nm。HPT处理后的高温退火导致前者析出η-Ni（3）Ti，后者析出σ-FeCr。在HPT处理的试样，氢扩散率提高，通过短路扩散，因为人口增加的晶界相比，增加的机会，氢捕获位错。对于具有沉淀物的HPT退火后的试样，氢扩散受到eta-Ni（3）Ti沉淀物上的氢捕获的阻碍，但不受σ-FeCr沉淀物的影响。这取决于氢和组成元素之间的亲和力。(C)2011 Elsevier B. V.保留所有权利。
This study was conducted to clarify the effects of grain boundaries and precipitates on room-temperature hydrogen transport in two types of austenitic stainless steels with ultrafine-grained structures produced by high-pressure torsion (HPT) and subsequent annealing. The grains in the Fe-25Ni-15Cr (in mass%) alloy containing Ti and the Fe-25Cr-20Ni alloy were refined by the HPT-processing to similar to 150 and similar to 85nm, respectively. The high-temperature annealing after the HPT processing led to the precipitation of eta-Ni(3)Ti for the former and sigma-FeCr for the latter. In the HPT-processed specimens, hydrogen diffusivity was enhanced through short-circuit diffusion because of the increased population of grain boundaries in comparison with the increased opportunity of hydrogen trapping on dislocations. As for the post-HPT-annealed specimens having the precipitates, the hydrogen diffusion was hindered by the hydrogen trapping on eta-Ni(3)Ti precipitates, but was not affected by sigma-FeCr precipitation. This depends on the affinity between hydrogen and constituting elements. (C) 2011 Elsevier B.V. All rights reserved.