Effects of Potential and Strain Rate on the Cracking Behavior of Alloy 182 Weld in Hydrochloric Acid Solution

The environmentally-assisted cracking (EAC) behavior of Alloy 182 weld in 0.05 M hydrochloric acid solution was investigated by employing slow strain rate testing (SSRT) technique. The potentials applied during SSRT at a strain rate of 8.3×10^-7 s^-1 were controlled at cathodic, active-to-passive transition, passive and transpassive potential regions, respectively. The experimental results showed that Alloy 182 was most susceptible to cracking in 0.05 M hydrochloric acid solution under cathodic polarization condition. In the active-to-passive transition as well as in the transpassive potential regions, the weld also suffered EAC. However, in the passive potential region, the weld was immune to EAC. The strain-rate-dependent EAC behavior was observed in 0.05 M hydrochloric acid solution at an applied potential of -50 mV_SCE (in the active-to-passive transition region). The results indicated that hydrogen-assisted cracking (HAC) participate in the cracking process under anodic polarization condition.