Based on various mechanisms of hydrogen diffusion in metals, different crack propagation models have been developed. Here, empirically specified model of crack propagation in structure components, which are simultaneously subjected to aggressive hydrogen environment influence and cycling, is presented. The model uses two different approaches to problem solving, i.e. the influence of aggressive hydrogen environment on material and the fatigue. A developed environmental assisted cracking model assumes that either the influence of aggressive hydrogen environment or the fatigue initiates a local fracture of structure component. This model enables estimating a structure component life.