抄録
We investigated the effect of hydrogen and prestrain on the tensile properties of a low carbon steel plate JIS-SGP (0.078C-0.012Si-0.35Mn). The steel gas pipeline material JIS-SGP, which is one of candidates for hydrogen gas pipelines, is produced from the low carbon steel plate by plastic working and welding. The hydrogen content increased by hydrogen charge after prestraining. The reduction of area was not affected by prestraining in the uncharged specimens, but it was affected by prestraining in the hydrogen charged specimen. The reduction of area decreased linearly with increasing hydrogen content in the hydrogen charged specimens. The void growth in the specimen has a good correlation with the reduction of area. The voids were elongated along the tensile axis in the uncharged specimens. On the other hand, the voids were elongated in the direction perpendicular to the tensile axis in the hydrogen charged specimens. The mechanism of development of dimples and voids in the hydrogen charged specimens should be noted to understand the basic mechanism of hydrogen embrittlement.
