The oxidation resistance of ceramic overlayer coating on STD 61 was studied by thermogravimetric analysis at 800 . CrN, TiN and composite of these coatings were deposited by arc ion plating. Among the investigated coatings, the best resistance was sho...
The oxidation resistance of ceramic overlayer coating on STD 61 was studied by thermogravimetric analysis at 800 . CrN, TiN and composite of these coatings were deposited by arc ion plating. Among the investigated coatings, the best resistance was shown in CrN deposited specimen, followed by composite depositon of CrN and TiN. The parabolic rate constant of CrN coated STD 61 was 0.O0075 mg2/cm4/hr, whereas that of uncoated one was 0.4677 mg2/cm4/hr. The effect of ion nitnding as a pretreatment under the ceramic layer was evaluated. It was found that nitriding was detrimental to the oxidation resistance. The oxidized products were analyzed by SEM, EDS and XRB. The mechanism of oxidation of ion plating and nitriding was discussed.