Surface hardened specimens with cuts endurance limit dependence on cross-section sizes
It's experimentally established that hardened specimens cross-section sizes increase leads to the increase of compressive residual stresses in the surface layer and the decrease of reactive tensile stresses in the core under the same type of hardening. It's necessary to increase the thickness of surface hardened layer with compressive residual stresses proportionally to the parts dangerous cross-section sizes for hardening effect preservation. It's been shown that surface hardening influence on the parts endurance limit evaluation using the average integral residual stresses criterion leads to the slight dispersion of the stresses concentration coefficient versus the same evaluation using the dangerous section surface residual stresses criterion. So the average integral residual stresses criterion can be recommended for the hardened parts with stresses concentrators endurance limit forecasting.