Analysis on Mechanical Parameters at SCC Tip in Fusion Boundary Region of Dissimilar Weld Joint

摘要

Microstructure and material mechanical property in the fusion boundary (FB) region of dissimilar weld joints in light water reactors are quite complicated and different from the bulk material, which make it more susceptible to stress corrosion cracking (SCC) and produce high weld residual stress. To investigate SCC behavior in the FB region of an Alloy 182-A533B dissimilar weld joint, considering the mechanical heterogeneity, mechanical parameters ahead of crack tip with different sampling location are analyzed. It suggests that the stress near crack tip would be significantly higher in a high yield stress material while the strain would be much smaller, and the effect of the material properties around FB region on strain is smaller than that on stress. The result of J-integral indicates FB region would be a barrier when crack in Alloy 182 weld propagates towards LAS.