Ratcheting and fatigue behavior of Eurofer97 at high temperature, part 1: Experiment

Abstract

Eurofer97 is considered as one of the structural material candidates for in-vessel components of future fusion reactor. Due to frequent startups, shutdowns and load changes in reactor, the material is under complex cyclic loadings. This work investigates the mechanical behavior of Eurofer97 under various cyclic loadings, including strain-controlled LCF tests and stress-controlled ratcheting tests at high temperatures 450°C and 550°C. Various influencing factors on ratcheting, such as stress magnitude, stress ratio and stress rate are evaluated. Since Eurofer97 is developed based on conventional grade 91 ferritic martensitic (FM) steels, corresponding data of mod.9Cr-1Mo FM steel P91 are also presented for comparison.