SODIUM COMPATIBILITY STUDIES OF LOW FRICTION CARBIDE COATINGS FOR REACTOR APPLICATION.

Abstract

Based on isothermal sodium corrosion and thermal cycling studies, the D-gun applied chromium carbide coatings, with nichrome and Inconel 718 binders, are the best candidates for coating the stainless steel fuel assembly duct load pads in the fast flux test facility. Average sodium corrosion rates of these coatings at 1160 F were less than equivalent to 0. 25 mpy (6. 35 mu m/hr). The results of sodium exposure at 1160 F or thermal cycling in sodium between 1160 and 800 F have ruled out plasma sprayed chromium carbide and titanium carbide coatings with molybdenum or nichrome binders for use in this application.