The influence of temperature gradient on the corrosion of materials in molten fluorides

The corrosion of materials is a great challenge for the application of a molten salt nuclear reactor using molten fluoride salts with dissolved fissile material as fuel or using clean molten salts to cool solid nuclear fuel. Temperature gradient is one of the main driving forces. In present investigation, the corrosion of Cr and alloy GH3535 in molten (Li,Na,K)F with the temperature gradients of 600-700 and 650-700 °C is investigated. The experimental results indicate that the difference in the temperature of the melt causes the difference of the corrosion potential, and thus leads to the occurrence of galvanic corrosion. The corrosion of hot-end samples is accelerated, with a higher effectiveness for a higher temperature gradient.