Creep-Fatigue Damage Evaluation of 2.25Cr-1Mo Steel in Process Reactor Using ASME-NH Code Methodology

摘要

Critical equipment of nuclear power plants and petrochemical industries is sometimes subjected to both creep and fatigue loading simultaneously. Under combined creep-fatigue loading, the creep deformation affects the fatigue behavior of the material depending on the relative duration of stress relaxation due to creep within service life. In the present paper, evaluation of creep and fatigue damage is carried out for a process reactor using elastic analysis method of ASME-NH code. The reactor material is 2.25Cr-1Mo steel. The stress evaluations are carried out at outlet nozzle where stresses are observed to be maximum. Effect of three parameters, that is, the maximum hold temperature, the duration of hold time at highest temperature and the rate of temperature change on combined creep-fatigue damage, is studied. This work provides guidelines for performing creep-fatigue analysis for similar pressure components.