Finite element calculation of creep crack initiation on an IP-turbine rotor using the C*-parameter

Abstract

Creep crack initiation results from a heat resistant turbine rotor steel of type I %Cr-l %Mo-0.6%Ni-0.3% V are described by the parameter C*, which is calculated on the basis of an inelastic finite element analysis. The application of these results for the calculation of creep crack initiation of an assumed internal defect in the center of an IP rotor is discussed. The time to creep crack initiation estimated on the basis of the C*-concept is compared with a predicition by means of the analytical two-criteriaconcept.

Creep-Fatigue Interaction in the AISI H11 Tool Steel

“…Premature failure may occur after a certain number of loading/unloading cycles as a result of creep-fatigue interaction. Many investigations have been carried out to analyze the initiation and propagation of microcracks under creep-fatigue conditions [3][4]. In parallel to experimental investigations, numerical simulations through finite element (FE) calculations have been performed to predict the levels of stress and strain as well as the lifetime of the tools during the extrusion process.…”