通过全浸腐蚀实验, 采用XRD, OM, SEM 和 EDS研究了Hastelloy C276和Hastelloy N合金在80%CaCl2+20%CaF2(质量分数)熔盐中的腐蚀行为. 结果表明, Hastelloy C276和 Hastelloy N合金均发生晶间腐蚀, 其具体形式为Cr和Mo元素沿晶界发生选择性脱溶腐蚀. 由于腐蚀层和腐蚀产物对元素扩散的阻碍作用, Hastelloy C276和Hastelloy N合金在熔盐中的腐蚀速率均逐渐减缓, 其腐蚀失重$C$与腐蚀时间$t$符合C=Ktn关系.
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 intergranular 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=Ktn.
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