Evaluation of crack resistance of carbon and low-alloy structural steels under conditions of hydrogen charging

Fracture of materials caused by hydrogen embrittlement is a very serious problem in the operation of pipelines subjected to the effect of hydrogen charging (hydrosulfide-bearing media, external corrosion cracking under stress, contact with active sulfate-reducing bacteria, etc.). As a rule, this damage occurs in the final stage of the process of crack propagation initiated by hydrogen. In order to predict the transition from a subcritical stage to a critical stage of unstable fracture and to calculate the strength characteristics of pipes with cracks of a metallurgical or operational origin we must know the permissible margin of safety with allowance for hydrogen absorption in the operating period.