Crack propagation engineering model: stress intensity dependence of crack growth rate in hydrogen embrittlement material

摘要

Based on various mechanisms of hydrogen diffusion in metals, different crack propagation models and stress intensity dependence of crack growth rate have been developed. Engineering model of another hydrogen-assisted cracking in metal materials is presented in this paper. This model is based on simultaneous solution of two various problems: diffusion of hydrogen in metal problem and fracture mechanics problem. Special characteristic, which bonds material and environment, is introduced to colligate these two problems together in proposed model. Engineering model is discontinuous in the present case. The value of crack growth is not a constant. Crack moves out when the concentration of hydrogen in the crack tip reaches maximum permissible value. This magnitude is chosen from the special characteristic mentioned above. The stress intensity dependence of crack growth rate, calculated by authors, has a good correlation with Panasyuk's experimental data.