Corrosion Mitigation of Ferritic Steels in HF-Containing FLiNaK by Titanium Sacrificial Anodes

Abstract

Sacrificial anode methods are focused upon for suppression of the tritium fluoride corrosion of structural materials in molten salt blankets in fusion reactors. Stainless Steel 430 (SS430) is immersed into hydrogen fluoride (HF)-containing LiF-NaF-KF (FLiNaK) for 6hours at 773 K with Ti. It has been found that (1) the presence of Ti suppresses the corrosion of SS430 by HF. Further, by the electrical connection between SS430 and Ti, (2) Ti can sufficiently lower the potential of SS430, (3) the weight loss of Ti increases, and (4) the grain boundary corrosion of SS430 by Cr dissolution is mitigated. The applicability of sacrificial anode methods to molten salt blankets has been established.