Environmentally assisted fatigue behavior of 308L weld metal in borated and lithiated high-temperature water

Abstract Environmentally assisted fatigue (EAF) tests in borated and lithiated high-temperature water were conducted to investigate the effect of dissolved oxygen (DO), strain rate and strain amplitude on fatigue life of 308L weld metal. It was found that fatigue lives were comparable in 0.005 ppm DO and 0.1 ppm DO water, and decreased slightly with decreasing the strain rate from 0.04%/s to 0.004%/s. The EAF effects were more pronounced at low strain amplitudes. The EAF cracking mechanisms involved with dendrite boundary orientation relative to cyclic stress axis and δ-ferrite in 308L weld metal are discussed.