Proposal of Design Method Enabling Cr-Mo Steels to be Used in High-Pressure Hydrogen Gas Environment

Abstract

This paper presents a design method enabling Cr-Mo steel to be used in high-pressure hydrogen gas. On the basis of a series of experiments, it is suggested that the components can be designed by the conventional design by rule if the following criteria are satisfied under the maximum design pressure of hydrogen gas : firstly, there is no degradation in the tensile strength in slow strain rate tensile (SSRT) test, and secondly, there is no degradation in the fatigue limit. It is also proposed that the components can be designed by the conventional design by analysis, if the following criteria are satisfied under the maximum design pressure of hydrogen gas : firstly, there is an upper bound on the acceleration of fatigue crack growth in hydrogen environment, and secondly, the maximum stress intensity factor of a near-through-wall crack is less than the value of the fracture toughness in air.