A phenomenological life evaluation method for corrosion fatigue

Abstract

AbstractConsidering interacted damage accumulations induced by corrosion, cyclic fatigue, and stress corrosion cracking, a phenomenological corrosion fatigue (CF) life evaluation formula has been proposed. A concept of nominal CF limit has been introduced, which indicates whether cyclic damage accumulation is active or not. It is found that cyclic fatigue damage accumulation enhanced by corrosion is the dominative damage under relatively high stress amplitudes (compared to the nominal limit), whereas, under low stress amplitudes, corrosion damage accumulation would become the dominative one. Stress amplitudes below the nominal fatigue limit would lead to CF too due to corrosion damage accumulation, which can finally make the effective amplitude larger than nominal limit. Once the parameters included in formula have been determined by uniaxial tests, CF life under any complicated stress state could be estimated in a unified way.