Corrosion resistance of ZrO2 films under different humidity coal gas conditions at high temperature

ZrO2 films were prepared on 304 stainless steel by sol-gel method. The resistance of ZrO2 films to high temperature and high humidity coal gas corrosion was studied. Experiments show that the film on the surface of the sample without vacuum treatment is ZrO2-Cr2O3-Fe2O3 (ZrO2-passivation film) composite film. This film is effective against intergranular corrosion, however, as the corrosion humidity increases, sulfide corrosion occurs on the surface of the coated sample. The XPS test showed no change in the composition of the ZrO2 film before and after etching. The sulfide of the sample is caused by Cr2O3-Fe2O3. The high density ZrO2 film is very resistant to high temperature coal-gas corrosion.