The electrochemical study on mechanical and hydrogen embrittlement properties of HAZ part as a function of post-weld heat treatment in SMAW

Marine structures exposed to severe marine environment should be protected against corrosion in an appropriate way. The cathodic protection method is being widely used in marine structural steel, however, high strength steel for marine structures is easily affected by hydrogen embrittlement (HE) at heat affected zone parts due to over-treatment during impressed current cathodic protection. Elongation and time to fracture were decreased due to HE with shifting to low potential, however, the susceptibility of HE was decreased by post-weld heat treatment (PWHT). It is suggested that an optimum cathodic protection potential not causing HE is from −770 mV (SCE) to above −875 mV (SCE) regardless of PWHT condition.