Creep‐fatigue analysis of the steel AISI type 316 component failure

Abstract

AbstractThe purpose of this work is to extend a typical creep‐damage model in order to describe material behavior under variable thermal and mechanical loading in wide stress range. The model basis is creep constitutive law in form of hyperbolic sine stress response function proposed by Nadai. The constitutive law is extended to assume the damage process under creep and fatigue by the introduction of scalar damage parameters and appropriate evolution equations according to Kachanov‐Rabotnov concept. The material constants for model are identified by fitting the experimental creep and low‐cycle fatigue data for the steel AISI type 316 at the range of temperatures 500°C – 750°C. The development of such model is motivated by the well described failure case study of high‐temperature components at unit 1 of Eddystone power plant, which have operated during 130520 hours under creep‐fatigue interaction conditions. The main steam piping (MSP) from this power plant is selected for thermo‐mechanical creep‐fatigue analysis applying the proposed material model. The estimated values of damage parameters comply with the real location of the component failure and a scatter of experimental data on creep‐fatigue interaction diagram. (© 2011 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)