Assessing Corrosion Fatigue Characteristics of Dissimilar Material Weld between Alloy617 and 12Cr Steel Using Buttering Welding Technique

In this study, dissimilar material welding between Alloy617 and 12Cr steel was performed using the buttering welding technique on the 12Cr steel side in order to increase the weldability. After multi-pass welding, post weld heat treatment (PWHT) was performed in order to reduce the welding residual stresses, and metallurgical microstructures were observed on dissimilar material weld. Additionally, the corrosion fatigue crack growth characteristics of dissimilar material weld was assessed according to Fracture Mechanics. Based on the results, the fatigue and corrosion fatigue strength of dissimilar material weld between Alloy617 and 12Cr steel did not show a big difference prior to and after post weld heat treatment. Fatigue and corrosion fatigue crack growth of dissimilar material weld were slightly faster than those of similar material weld of Alloy617. However, the characteristics of fatigue and corrosion fatigue crack growth did not show a big difference prior to and after PWHT.