7. Liquid hard deposits

7.1 Immersion in molten salt baths

Due to their high reactivity, molten salt baths containing chlorides with added metal elements such as Cr, V are likely to produce surface reactions of the dissociation and exchange type at temperatures close to 1,000°C. These reactions result in the supply and diffusion of metallic elements from the bath into the substrate. Back-diffusion of carbon from the substrate to the surface results in the creation of a deposit of carbides, whose thickness does not exceed 15 µm due to the...