A nonlinear lifetime prediction method for un‐ and low alloyed steels by damage determination based on non‐destructive measurement techniques

Abstract

Materials used in nuclear power plants are exposed to cyclic loading, which is why the understanding of fatigue behaviour is of great importance. Because of high time investments and resulting increased costs, Lifetime Prediction Methods, which significantly reduce the amount of specimen, have already been developed. Within this paper, the Lifetime Prediction Method MiDAcLifeincr is presented, which enables a determination of a trend S‐N curve in the High‐Cycle‐Fatigue‐regime based on only one fatigue test and the combination of conventional fatigue testing with NDT‐related measurement techniques. The process‐orientated monitoring of the cyclic deformation behaviour provides the basis for the time‐ and cost‐effective provision of fatigue data. Compared with previous methods, the consideration of variable loading is an essential aspect of the research application. The test material is a 20MnMoNi5‐5 steel, the results of which are extended to include other steels for validation reasons.