Corrosion Resistance of Degraded STS310S and STS347H by Cr-free Modified Si Organic/Inorganic Hybrid Coating Solution

Abstract

Austenitic stainless steels generally experience the occurrence of chromium-depleted zones at the boundaries, known as sensitization, caused by the carbide precipitation that takes place due to a welding process or heat treatment. Normally, the depleted zones become the focus of the intense corrosion. In this study, the Cr-free organic/inorganic hybrid solution was developed, and the artificially degraded STS316S and STS347H with the solution-coating investigated the corrosion resistance by salt spray test. Both the OIBD-1 and OIBD-2 solutions improved the corrosion resistance of STS310S and STS347H. The corrosion resistance with the OIBD-1 solution was better than that of OIBD-2 solution.Additionally, Both solutions have been proven excellence in adhesion ability, boiling water resistance and flexibility. However, a problem of rubbing after the boiling was found out to be overcome.