The influence of residual stresses thermal exposition samples of alloy ep742 after ultrasonic hardening

Calculation-experimental method investigated residual stresses in the plane of polycrystalline samples of alloy EP742, after grinding, ultrasonic hardening and thermal exposition (temperature exposure without load at T=650 °C). Revealed regularities of distribution of residual stresses through the thickness of the surface layer of the samples. It is shown that in times termal exposition reduces the level of compressive residual stresses and produces a shift of the maximum depth of the sample. The effect of residual stress fields and termal exposition an increment in the fatigue limit.