Hot Corrosion Behaviors of Protective Coatings on M38 Super Alloy

In order to study hot corrosion behaviors of the high temperature protective coatings on M38 super-alloy, four modified aluminide coatings (NiCr-CrAl coating、Al-Si coating、Al-Ti coating and Co-Al coating) were prepared on the surface of the M38super-alloy. The microstructures and the hot corrosion behaviors in the salt of 25 wt.% NaCl + 75 wt.% Na₂SO₄ at 900℃were investigated.Results showed that four modified aluminium coatings can increase the corrosion resistance of the M38 superalloy. Furthermore, the Al-Ti coating provided the best protection to the alloy in this kind of mixed salt.