Influence of the combined-effect of NaCl and Na2SO4 on the hot corrosion behaviour of aluminide coating on Ni-based alloys

The hot corrosion behaviour was investigated for pack-cemented Si-modified aluminide coating on the K438 Ni-base alloy when covered by NaCl, Na2SO4, and 50% NaCl +50% Na2SO4 (mass fractions) at 1050 degrees C in air. The primary aim of this work was to add NaCl and Na2SO4 only once to the surface of coating to study the effect on the subsequent and long-term hot corrosion behaviour of coating. After 120 h hot corrosion, covered by NaCl and 50% NaCl +50% Na2SO4 (mass fractions) for the coating, generated the maximum and minimum oxides spallation per unit area, respectively. Combined-effect of NaCl and Na2SO4 decreases oxides spallation. (C) 2019 Elsevier B.V. All rights reserved.