In order to investigate the cracking tendency of
cathodically polarized SEACURE superferritic stainless
steel, a series of potentiostatically controlled tests were
conducted in flowing natural seawater. U-bend and tensile
specimens were used to determine the threshold potential and
limiting fracture stress.
The microstructure was examined using a metallurgical
microscope and a chemical analysis was conducted across the
grain boundary. These results were then correlated to
hydrogen assisted cracking, by performing SEM and EDAX
analyses on fractured U-bend and tensile samples. Finally a
model was developed which explained the predominantly
intergranular cracking in the static stress condition and
also accommodated the transgranular failure during dynamic
loading.