Short-crack modelling of the effect of corrosion pits on the fatigue limit of 12% Cr steel

Abstract

Comprehensive data on the fatigue limit of smooth uncorroded specimens and specimens with single corrosion pits of a 12% Cr steel for steam-turbine blades have been generated by means of ultrasonic fatigue testing. The threshold for fatigue-crack growth has also been determined. Available (short-)crack models due to El Haddad and Härkegård and Smith and Miller generally yield safe predictions for the fatigue limit of the pitted specimens, whereas Murakami's √area model yields inconsistent predictions in the present case.