A Study on Corrosion Fatigue Crack Propagation Behavior of Butt Welded Joint of High Tensile Strength Steel in Synthetic Sea Water

Abstract

The corrosion fatigue crack growth behavior in the butt welded joint of high tensile strength steel has been studied in a synthetic sea water and discussed in relation to the welding residual stress and corrosion deposits.
For the base metal, the effect of synthetic sea water on da/dN depended on the stress ratio. At a high stress ratio, a little acceleration of da/dN by the synthetic sea water was observed while at a low stress ratio the da/dN tended to be lower than that in air. For the welded joint, the da/dN was affected by a compressive residual stress in both synthetic sea water and air, and was greater in air than in synthetic sea water. Such a crack growth behavior is related to the crack opening and closure behavior which is influenced by the corrosion deposits and the compressive residual stress.