Carbide Sensitization and Intergranular Corrosion of Nickel Base Alloys

Abstract

A thermodynamic theory has been used to predict the chromium content at equilibrium with chromium carbide particles and a matrix containing Ni-10Fe-16Cr for varying carbon contents and heat treatments. Corrosion measurements and electron microscopic studies have been used to confirm the predictions made by the theory. An important surface effect produced during the solution heat treatment is reported. It is concluded that sensitization of Inconel 600 occurs by a chromium depletion mechanism similar to that which takes place in stainless steel.