Salt Fog Corrosion Behavior of Nanostructured TiAlN and AlCrN Hard Coatings on ASTM-SA213-T-22 Boiler Steel

In this work, tialn and alcrn coatings were deposited on astm-sa213-t-22 boiler steel using balzer’s rapid coating system (rcs) machine under a reactive nitrogen atmosphere. the corrosion resistance of the substrate, tialn-coated and alcrn-coated samples in a 5 wt% nacl solution was evaluated and compared by salt fog (spray) test for 24 hrs, 48 hrs and 72 hrs. the weight loss per unit area increases with the duration of the test. the samples were monitored and analyzed by using weight loss measurement, xrd and sem/edax techniques. the weight loss per unit area in case of nanosructured thin tialn coating is less than as compared to the nanostructured alcrn coating and uncoated boiler steel in all test conditions.