The effect of post-weld heat treatment affecting corrosion resistance and hydrogen embrittlement of HAZ part in FCAW

Evaluation of corrosion resistance of material surface was investigated with electrochemical factors, such as corrosion potential, corrosion current density with parameters of as-welded, post-weld heat treatment (PWHT) of 550, 600, 650 °C for a RE36 steel and mechanical properties such as elongation, hydrogen embrittlement and analysis of SEM fractography were also investigated with slow strain rate test (SSRT) method with applied constant cathodic potential in case of as-welded and PWHT of 550 °C. An optimum temperature for corrosion resistance improvement was apparently observed at 550 °C of PWHT and elongation was also increased with PWHT of 550 °C than that of as-welded condition. Therefore, the susceptibility of hydrogen embrittlement was considered to be decreased with PWHT of 550 °C compared to that of as-welded condition and to be increased according to potential shifting in the low direction.