Lead-induced stress corrosion cracking behavior of mechanically surface-treated alloy 690

Abstract

Lead (Pb) is one of the impurities that cause stress corrosion cracking (SCC) of the tubing material in the steam generator (SG), the corrosion behavior of surface mechanical attrition treatment (SMAT) treated surface was measured for alloy 690 in simulated SG condition with and without Pb contamination. Even though the polarization curves indicated the corrosion potential of SMAT-processed specimens shifted negatively, the positive effect of SMAT on resistance of SCC was observed. The reduced susceptibility to lead-induced stress corrosion cracking may be attributed to the formation of stable passive film and the significant compressive stress on the surface induced by SMAT.