Impact of multi-component doping effect on corrosion mechanism of NiCrMoNb model alloy in molten chloride salt-solar salt mixture

To enhance the corrosion resistance of alloys in chloride-containing solar salt environment, a multi-component alloy by doping Co and Fe to partially substitute Ni in the NiCrMoNb model alloy is fabricated in this study. The results demonstrate that the the doped Co/Fe promote the formation of dense and abundant oxide layer on the alloy surface at 600 °C in molten chloride salt-solar salt mixture. Despite localized corrosion poles still exist, the formation of transverse cracks is notably suppressed. Moreover, after spallation of corrosion products, the Co/Fe doped NiCrMoNb alloy exhibits accelerated response speed through rapid reformation of compact oxide layer, effectively mitigating subsequent corrosion rates.