CORROSION BEHAVIORS OF Ni-Cr-Mo CORROSION RESISTENCE ALLOYS IN CaCl2-CaF2 MOLTEN SALT

The corrosion behaviors of Hastelloy C276 alloy and Hastelloy N alloy in 80%CaCl2+20%CaF2 (mass fraction) molten salt were investigated by XRD, OM, SEM and EDS. The results show that intergranular corrosion takes place in the two alloys, and the form of intergran- ular corrosion is a type of selective corrosion, i.e., the desolutions of Cr and Mo occur along the grain boundary. The corrosion rates of the two alloys decelerate with the increases of corrosion time because of the hindering effect of corrosion products on the element diffusion, and the relationship of mass loss (C) and corrosion time (t) can be described by formula of C = Kt n .