Cr-Mo鋼の高圧水素SSRT 特性に及ぼす微細組織の影響

抄録

In a high pressure hydrogen gas environment, there is a risk of "hydrogen embrittlement (HE)" by hydrogen entered to the steels. Therefore, many experiments of steels in high pressure hydrogen gas have been conducted such as tensile, fatigue and so on. However, there are little knowledge of influence of the material microstructure on HE. There is a possibility of HE susceptibility of steels depending on the material microstructure. Therefore, objective of this development is clarification of the microstructure to excellent HE resistance. As a result of Slow Strain Rate Tensile (SSRT) test under hydrogen environment, tempered martensite structure with finely cementite dispersed was most excellent in HE resistance. The reason for this is considered that the generation of micro voids, which is the initiation of surface cracks affecting ductility of SSRT, was suppressed.