高強度マルテンサイト系ステンレス鋼JIS-SUS630 (H1150)の引張特性に及ぼす水素チャージの影響

抄録

Tensile properties of high-strength martensitic stainless steel, JIS-SUS630 (H1150) were investigated with hydrogen-charged specimens. The reduction in area of the steel was more degraded with a higher hydrogen content. The non- and hydrogen-charged specimens failed by a cup-and-corn fracture; however, the shear stress fracture region of the hydrogen-charged specimen was larger than that of the non-charged specimen. The normal stress fracture surface of the hydrogen-charged specimen was covered with quasi-cleavage intergranular-like surface and fine dimple, different from that of the non-charged specimen. In the hydrogen-charged specimen, voids grew in the direction perpendicular to the loading direction and caused the quasi-cleavage and intergranular-like fracture. A series of experimental results inferred that the degradation in tensile ductility and unique fracture surface morphologies of the steel were attributed to localized slip deformations by hydrogen.