材料期刊网

Ti(0.7)Al(0.3)N and Ti(0.68)Al(0.30)Hf(0.02)N coatings were deposited on 1Cr-11Ni-2W-2Mo-V stainless steel by arc-ion plating (AIP), and their oxidation and corrosion performance were characterized using TGA, TEM, SEM/EDS, EPMA and XRD. The oxidation behavior of the coatings at 800 A degrees C for up to 100 h was investigated, and the results showed that the introduction of hafnium into the Ti(0.7)Al(0.3)N coating dramatically improved the oxidation-resistance of the coating in air. Compared to the Ti(0.7)Al(0.3)N coating, the presence of Hf in the nitride coating promoted the outward diffusion of Al, and suppressed the outward diffusion of Ti and inward diffusion of O. The Ti(0.7)Al(0.3)N coating was completely oxidized and formed a layered scale after oxidation at 800 A degrees C for 20 h in air. Meanwhile, local serious oxidation of the substrate occurred. Corrosion tests of the coatings with a NaCl deposit in wet oxygen at 650 A degrees C for 10 h were also conducted, and the results showed that the Ti(0.7)Al(0.3)N coating suffered serious local corrosion, while a thin and dense scale formed on the surface of the Ti(0.68)Al(0.30)Hf(0.02)N coating, and its anti-corrosion performance was remarkably enhanced.