Creep damage analysis of thin-walled pressure vessel based on continuum damage model under static loading

Abstract

UNS N10003 alloy is wildly used as a heat-resistant material for components to be used in high temperature thorium molten salt reactor (TMSR). Because of high temperature operating environment, prediction of its creep behavior is required for safety assessment of reactors. In this study, a series of uniaxial tensile creep tests has been conducted at 650°C in an applied stress range from 220 MPa to 380 MPa. A creep damage model for UNS N10003 alloy based on Lemaitre's work has been derived as well as a creep constitutive equation for modelling creep strain. The experimental data have been used to determine parameters in the constitutive equation and the damage model. The model has been applied to structural integrity assessment of a thin-walled pressure vessel design for TMSR. The numerical results indicate that the pressure vessel design for TMSR is sound and safe in its designated 10-year design life.