Abstract
Intergranular Stress Corrosion Cracking (IGSCC) and Intergranular Corrosion (IGC) behaviors of nickel-base weld metals of Types 82 and 182 were examined by means of various accelarated tests in oxygenated high temperture pure water and the ASTM G28 test, respectively. Ordinary nickel-base weld metals showed large heat-to-heat variations in IGC and IGSCC susceptibility. The behavior could be characterized in terms of stabilization parameter (N), which was defined as the number of atoms of stabilization elements per a carbon atom of material itself. The SCC resistant, new weld metals could be successfully produced by the stabilization parameter (N) control, here, mainly by niobium addition and carbon adjustment. The nickel-base weld metals of high N values (≥12) were highly resistant to IGC and IGSCC. The theoretical mechanism of stabilization parameter (N) control was discussed.
