Metallic impurities induced corrosion of a Ni-26W-6Cr alloy in molten fluoride salts at 850 °C

The effect of metallic impurities on corrosion of a Ni-26W-6Cr alloy in molten FLiNaK salts at 850 degrees C was investigated. Results show that the Ni-26W-6Cr alloy exhibits the same excellent compatibility with fluoride salts as Hastelloy N alloy. Fe impurities in molten salts accelerate the diffusion of Cr in the alloy, which determines the corrosion degree of the alloy. Unexpected depletion of W from the alloy was observed, which mostly results from the presence of Mo impurity in the salts. Mo impurity should be limited because of the significant effect of W on the neutron spectra of reactors.

Automated summary

The study found that metallic impurities can accelerate the diffusion of Cr in Ni-26W-6Cr alloy, affecting the corrosion degree of the alloy. Additionally, the presence of Mo impurities in the salts can lead to unexpected depletion of W in the alloy.