DEVELOPMENTS IN THE SLIP-DISSOLUTION MODEL OF STRESS-CORROSION CRACKING

Stress corrosion crack growth by slip-dissolution was considered from the standpoint of electrolyte resistance and/or dissolved metal ion concentration in the crack, using a trapezoidal model crack geometry. The ohmic potential (IR) drop and dissolved metal ion concentration in a crack with a pre-existing active path and passive walls in a conductive environment were predicted to be dependent upon stress and crack velocity but not upon crack length. Concerns about the saturation of ions or very high IR drops within cracks were shown to be unfounded for many conditions. Behavior of the type nu similar to epsilon(1/2) (where nu is velocity and epsilon is the strain rate) in highly resistive environments was argued to be a result of an ohmic effect associated with the crack opening angle.