Hydrogen embrittlement of a HSLA-100 steel in seawater

Hydrogen embrittlement of a copper precipitation strengthened and niobium m icroalloyed HSLA-1C0 steel on cathodic changing in synthetic seawater has b een studied using slow strain rate technique. The effects of potential appl ied for hydrogen changing, pre-charging with hydrogen and changes in strain rate have been studied. A loss in ductility in terms of drop in percent el ongation and percent reduction in area has been observed, the effect being prominent at potentials beyond -900 mV (SCE). SEM fractography shows an inc rease in brittle quasi-cleavage features with decreasing potential. A harde ning effect on hydrogen charging up to -700mV (SCE), followed by a softenin g effect, has been observed. Precharging has led to a similar behaviour, bu t an overall increase in the strength values compared to material without p recharging.