EVALUATION OF THE CONCENTRATION OF HYDROGEN IN THE PROCESS ZONE NEAR THE CRACK TIP

摘要

We construct, in the closed form, an analytic solution of the problem of diffusion of hydrogen in the process zone near the crack tip operating in contact with the ambient hydrogen-containing medium with regard for the preliminary hydrogenation of the material and the gradient of the field of mechanical stresses in this zone. It is shown that the hydrogenation of the material and the gradient of the hydrostatic component of the tensor of mechanical stresses induced in the material near the crack tip under loading may lead to the formation of the concentrations of hydrogen in this zone several times higher than in the medium. We also perform the experimental investigations and determine the local concentration of hydrogen in the process zone for specimens of 09G2S steel.