Fatigue Damage Development in 14MoV6-3 Steel for Power Plant Pipes Monitored by Digital Image Correlation

Abstract

In this paper, fatigue damage development of 14MoV6-3 (13HMF) power engineering steel was studied through different experimental and analytical approaches. The specimens machined from the as-received pipe were subjected to fatigue loading and simultaneously monitored using the digital image correlation (DIC) technique. The damage development was analysed through microstructural observations of fracture surfaces and further described as a function of the fatigue damage parameter D and the fatigue damage measure ϕ. The combination of such parameters’ evolution with the number of cycles to failure and the DIC technique enables a determination of separate stages of damage development. It was found that dynamics of damage could be effectively exposed within the first 100 cycles.