Early damage and fatigue crack initiation at ambient and elevated temperatures in heat resistant austenitic steel

Fatigue damage at ambient and at elevated temperature has been studied in advanced heat resistant austenitic steel. Cylindrical specimens were subjected to constant strain rate cycling and cycling with dwell in the tensile part of the cycle with different strain amplitudes. Surface relief evolution and initiation of surface and internal cracks were studied using high resolution SEM, FIB cutting, EBSD analysis, foil preparation and STEM imaging.