Research on Hot Corrosion Behavior of DZ40M and K452 Superalloys in NaCl Molten Salt

The corrosion of cobalt-based DZ40M and nickel-based K452 superalloy at 900 °C was investigated by NaCl salt coating. Accordingly, the differences in hot corrosion behavior were analyzed considering the development methods and elementary composition by comparing the two alloys’ failure. Then, the corrosion mechanism induced by NaCl was proposed by comparing oxidation and hot corrosion behavior. The relatively continuous Al2O3 and TiO2 formed on K452 superalloy with higher content of Al and Ti have lower solubility and less damage in Na2O. Thus, the hot corrosion rate of K452 is lower than that of DZ40M with higher content of C, Cr, and W.