Numerical Study on Creep Rupture Behavior of SA533B Low-Alloy Steel

摘要

Time-dependent loads may significantly affect on structural integrity of RPV (Reactor Pressure Vessel) under severe accident conditions respecting to the core melting. Especially, creep rupture at the high-temperature should be regarded as an important phenomenon to cope with failure of the RPV lower plenum. In this paper, creep behavior of SA533B as a typical reactor material was assessed based on several creep relationships such as Bailey-Norton's power law, MGR (Monkman-Grant Relationship) and MMGR (Modified Monkman-Grant Relationship). Creep rupture test data were referred from experimental projects of OECD/NEA. Subsequently, corresponding parametric FE (Finite Element) analyses were carried out for various temperature and loading conditions, of which results were used to establish an enhanced creep rupture evaluation method combined with the well-known LMP (Larson-Miller Parameter) of the low-alloy steel.