Corrosion Behavior of Ni-Cr-Mo Alloy in Vacuum Melted CaCl₂-20%CaF₂ Salt

The corrosion behaviors of two Ni-Cr-Mo alloys including 00Cr16Ni75Mo2Ti and Hastelloy N had been studied by immersion experiments in vaccum melted CaCl2-20wt%CaF2 salt at 800℃.The results show that the corrosion weight loss of the two alloys increased with the prolongation of time while the corrosion rate decreased.At the initial stage of the test the corrosion rate of the Hastelloy N alloy was obviously higher than that of 00Cr16Ni75Mo2Ti alloy.The main corrosion mechanisms of the two alloys both were the selective dissolution of alloying elements in the molten salt.The difference of the precipitated phases was the main cause which caused that the weight loss of the Hastelloy N alloy was significantly higher than that of 00Cr16Ni75Mo2Ti alloy.