The use of heavy liquid metals (HLM), such as Lead, Pb, is being considered as a coolant in Generation IV fast Reactors. However, structural materials suffer significant damage when in contact with HLMs. Both austenitic and ferritic-martensitic steels are considered and are susceptible to corrosion and/or degradation of mechanical properties. One of the approaches to mitigate erosion/corrosion problems is the use of coatings. This is a layer of a different chemical composition between the base material and the liquid metal coolant in order to prevent the bulk metal from corrosive effects. Coatings are proposed as a valid protection against high temperature damage in this environment. Their capability to grow more stable and protective oxides, by introducing the oxide forming elements (e.g. Al, Si,…) in higher amount, is proven to be an effective alternative to material engineering.

For this specific application, several coatings deposition techniques and compositions have been proposed and tested. In this work the High Velocity Oxygen Fuel, HVOF, combined with laser melting was selected for deposition of FeCrAlY coatings. The combination of the two technologies lead to a compact and adherent coating with an enriched content of Al. The method was evaluated in terms of the corrosion resistance of the coating and also its effect on the microstructure of the substrate alloy. Several attempts were carried out to modify spraying and laser parameters in order to minimise the effect on the substrate and keep the protective properties.

Results are discussed in terms of deposition parameters and protection characteristics.

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