Effect of Coating Process Temperatures on Hot Corrosion Be-havior Induced by Deposit of Sulfates Salts in Air at 750℃ for CVD Aluminized Coatings on K452 Superalloy
Aluminized coatings were deposited on K452 superalloy by chemical vapor deposition(CVD)technique at the temperatures 850,950 and 1050℃,respectively.The effect of deposition temper-ature on the corrosion behavior of K452 alloys without and with CVD aluminized coatings was compara-tively investigated beneath deposits of Na2SO4 and Na2SO4+NaCl(3±0.2 mg/cm2),respectively in air at 750℃.Then their cross-sectional morphologies and phase structures were characterized by SEM/EDS and XRD.The results showed that all the aluminized coatings exhibited better corrosion resistance to the deposits of Na2SO4 and Na2SO4+NaCl as compared to the bare K452 alloy after 50 h of corrosion.Notably,the corrosion resistance of the coatings was increased with the increase in deposition temperatures.