Evaluation of corrosion resistance of A516 Steel in a molten nitrate salt mixture using a pilot plant facility for application in CSP plants

Abstract

This paper evaluates the corrosion of A516 carbon steel in the binary Solar Salt (60 wt% NaNO3/40 wt% KNO3) by dynamic immersion test at 500 °C. To this end, a novel patented experimental facility enabling dynamic degradation tests of materials in contact with molten mediums was developed and used. Experimental results showed greater corrosion rates and thicker oxide layers in samples subjected to dynamic tests than the static ones. The dynamic test facility allows the simulation of (such as flux, thermocycling, etc.) of a CSP plant. The patented experimental pilot plant is a great step forward in learning about the physicochemical properties and behaviour of molten salts and also behaviour of substrates in contact with them under realistic working conditions.