Corrosion fatigue has long been known to reduce the lifetime of high alloyed steels. X2CrNiMoN22-5-3 duplex stainless steel is a viable candidate for corrosion and mechanical stress resistance. As a result, the corrosion fatigue (CF) of the Northern German Basin electrolyte at 369 K was examined using a specially built corrosion chamber. The lateral grain attack within corrosion pit chambers placed perpendicular to the strain applied was clearly linked to CF damage. Multiple fatigue cracks, as well as favoured austenitic phase degeneration and intact ferritic phase. Fracture termination with little to no base metal deterioration is characterised by a delta-like micro crack structure and a curved course. The cavity in the immediate subsurface zone is most likely related to the first crack cavity with significant austenitic phase deterioration. Crack initiation can occur as a result of early pit development followed by depassivation, or as a result of local depassivation followed by pit formation — both mechanisms result in crack propagation and early failure.
Department of Mechanical Engineering, Applied University of Berlin HTW, Berlin, Germany. and Federal Institute of Materials Research and Testing BAM, Berlin, Germany.
Department of Mechanical Engineering, Applied University of Berlin HTW, Berlin, Germany.