INFLUENCE OF 70 MPA HYDROGEN GAS ON SUS 630 FROM 77 K TO 373 K BY SIMPLE TESTING METHOD

摘要

The hydrogen environment embrittlement (HEE) on SUS 630 was evaluated by enclosing the hydrogen gas into a hole of the specimen at 77 K, 120 K, 190 K, 230 K, 260 K, 300 K, and 373 K. The pressure range of hydrogen gas was 10 MPa to 70 MPa. The slow strain-rate tensile (SSRT) tests were carried out and the relative reduction of area (RRA) was calculated by the ratio of the reduction of area (RA) in hydrogen gas and the RA in helium gas. The RA and tensile strength were smaller in the higher pressure of hydrogen gas. The RRA between 190 K and 260 K was almost zero, however, the HEE reduces at 77 K and 373 K. There was almost no HEE after changing to helium gas at the stress of just below the fractured stress in hydrogen during the SSRT tests.