Die thermische Stabilität von Eigenspannungen in kugelgestrahlten Oberflächen

Thermal Stability of Residual Stresses in Shot Peened Surfaces . In industry shop peening represents a well-known process to improve the fatigue properties of metallic components. However, the beneficial effect of the induced compressive residual stresses can be reduced if a component is subjected to higher temperatures during service. In this work the relief of the residual stresses as a function of time and temperature is calculated for a 12 %-chromium steel. Specifically, the results can be used for the prediction of the stress relief behaviour of gas turbine compressor blades. This model can also be applied to the determination of the mechanisms which are responsible for the residual stress relief. At temperatures above approximately 300 °C in this material the dominating mechanism is diffusion controlled creep whereas at lower temperatures the stress relief is caused by logarithmic creep.