PNNL

Abstract

Intergranular Stress Corrosion Cracking (IGSCC) of metals is often controlled by anodic (oxidative) dissolution of the metal at the crack tip. The anodic processes, in turn, depend on both crack-tip solution and grain boundary compositions. The latter are strongly influenced by alloying constituents and impurities that frequently segregate to (or away from) the grain boundaries during heat treatment and/or aging. For systems that exhibit anodic control, understanding the kinetics of the corrosion processes at crack tips and, in particular, determining how the kinetics are influenced by the presence and amount of grain boundary segregants, is critical to identifying both promising andproblematic alloys and in developing predictive crack growth models.