Corrosion Resistance of Stainless Steel and Pure Metal in Ternary Molten Nitrate for Thermal Energy Storage

Abstract

This study investigated the corrosion behavior of stainless steel and pure metals in contact with ternary molten nitrate used for thermal energy storage(TES).Weight changes were measured over 500 hours for stainless steels, 20hs for pure metals, and corrosion products were identified by scanning electron microscopy(SEM) and X-ray diffraction(XRD).Our research shows that SS310S, SS316L and SS321 all have good corrosion resistance to ternary nitrates due to their higher chromium and nickel content.In addition, compared to metal oxides, the alloy oxides produced in stainless steel have better protection against further corrosion of the metal substrate. In practical applications, reducing the content of oxygen in the contact zone between the molten salt and the metal container, as well as using a material with high nickel-chromium content, can effectively reduce the rate of corrosion.