STRESS CORROSION CRACKING OF INCONEL 600 AND INCOLOY 800 IN 50% NaOH AQUEOUS SOLUTION AT 140 degree C.

SCC stress corrosion of Inconel 600 (In 600) and Incoloy 800 (Iy 800) in 50% NaOH at 140 degree C was investigated using a constant strain rate method under electrochemically controlled potentials. SCC took place at a primary active region (approx. minus 0. 90 V, SCE) and a secondary passive region ( minus 0. 40-0. 05 V, SCE) in polarization curves at epsilon equals 4 multiplied by 10** minus **3 min** minus **1. SCC was found in both alloys and there was not much difference in the susceptibility between annealed and sensitized materials. Transgranular cracking occurred around 0V and intergranular cracking became predominant at higher or lower potentials than 0V.