HYDROGEN ATTACK ON AUSTENITIC STEEL 304 UNDER HIGH TEMPERATURE AND HIGH PRESSURE

The hydrogen attack of austenitic stainless steel 304 exposed to hydrogen under the pressure of 5 MPa at 733 K for 2×10~4 h in service was detected.The microstructure has been studied by SEM and TEM.Hydrogen was determined with molten samples which had tempered at.573,673,773,873,and 973 K for 6 h.The results showed that hydrogen attack in this steel was due to methane bubbles which resulted in occuring of Cr_(23)C_6.Thermodynamic analysis of hydrogen attack for stainless steel 304 was discussed.