Assessment of fatigue and electrochemical corrosion characteristics of dissimilar materials weld between alloy 617 and 12 Cr steel

In the current work, welding between dissimilar material (Nickel 617 and 12 Cr steel) was carried out by two types of techniques i.e. welds with and without buttering. Buttering welding was carried out on 12 Cr steel side to enhance the metallurgical compatibility of the weld. To evaluate the integrity of dissimilar weld between alloy 617 and 12 Cr steel, fatigue strength, fatigue crack growth in corrosion environment and in air was investigated. Potentio-dynamic polarization test was performed to assess the electrochemical corrosion susceptibility of these welds at different temperatures. The results showed that fatigue limits for buttering welded specimens were relatively higher than those without buttering welding in both the environments (air and corrosive medium), and the fatigue strength significantly decreased in corrosive environment. The electrochemical corrosion susceptibility increased with increase in temperature for both type of welds. Fatigue crack growth rate of dissimilar material welded specimen without buttering welding was slightly higher than that of buttering welded specimen. Buttering weld enhanced the corrosion characteristics and fatigue strength of weld between alloy 617 and 12 Cr.