Effect of Contaminants on Resistance To Stress Corrosion Cracking Of Ni-Cr Alloy 600 in Pressurized Water

Abstract

Abstract Numerous tests have shown that Alloy 600, a 76 nickel-15 chromium-7 iron alloy, has excellent corrosion resist­ance in pressurized high temperature water. The present tests were undertaken to determine the influence of possible contaminants in 600 F (316 C) pressurized water on corrosion behavior, using both single and double U-bend specimens. The double U-bend provided a combined stress and crevice specimen. Contaminants were sodium fluoride, air, lead powder, lead oxide, a petroleum hydrocarbon, and a mixture of lead powder and the hydrocarbon. Contamination and aeration were much in excess of any condition likely to be encountered in pressurized water reactors. Under certain conditions, some contaminants induced stress corrosion cracking.