The influence of roller strengthening on the endurance limit of samples with a pressurized hub

The roller strengthening influence on the endurance limit during bending of 25 mm diameter samples of steels 20 and 40Х with pressurized hub is experimentally researched. It has been found that roller strengthening increases the endurance limit considerably, especially of 40Х steel samples. The estimate of surface strengthening influence on the endurance limit by means of the residual stress criterion on the surface, and average residual stresses has shown that to forecast increasing the endurance limit of strengthened samples with a pressurized hub can be recommended to use the average residual criterion.