Analysis of thermoelastic stresses in forged products on account of the relaxation effect

Since stress is one of main factors in flake formation, it is important to understand the nature of the stress state of continuously cooling cylindrical forgings. For this purpose computer calculations of internal stress distribution were made as well as the possibility of elastic deformation relaxation during cooling of forging was taken into account.Calculations were carried out for several options at different cooling rates for three stress components - axial, radial and tangential. Calculations of the relaxation effect were made by processing and approximating the experimental data of 40KhGM steel creep in a temperature range of cooling after antiflake heat treatment.Calculations showed that at analytical calculations without account of relaxation the absolute stress value decreases and tends to zero when approaching room temperature, whereas calculations with account of relaxation of internal stresses showed residual stresses at the end of forging cooling. Moreover, they are compressive on the surface and tensile in the center of the forging. The impact of these stresses on the flake disclosure was shown.The second step was to analyze the influence of internal stresses on hydrogen diffusion and flake formation. The impact of external stresses on diffusion is usually limited to the decrease of the activation energy of diffusion to an additional value. Calculations have shown that this value has no effect on the activation energy.The results of this article can be useful to specialists dealing