High-temperature hydrogen resistance of stainless steels

At elevated temperatures, the influence of hydrogen on various mechanical characteristics of martensitic and disperse-hardened austenitic steels is different. The maraging steel has better characteristics of durability and plasticity and the critical values of static and cyclic crack resistance at temperatures of 450–600°K than the austenitic steel with intermetallic hardening. As a result of the intense temperature softening, its ultimate and yield strengths are much lower than for the austenitic steel. The austenitic steel has higher resistance in terms of the threshold value ∆Kth. At room temperature, the low-cycle fatigue limit proves to be most sensitive to the action of hydrogen, whereas at 673°K, the parameter Kfc for the maraging steel decreases.