Effect of Plasma Sprayed Yttria Stabilized Zirconia(YSZ) Coating for High Temperature Oxidation Resistance of Low Alloy Steel

Resumo

This paper investigates the influence of YSZ coating on high temperature oxidation behaviour of low alloy 2.25 Cr-1 Mo steel. The YSZ powder was plasma sprayed coated over 2.25 Cr-1 Mo steel substrate. The isothermal oxidation test of the coated and uncoated specimen was carried in air oxidation environment at 900°C. The weight changes of the specimen were measured at different intervals. The oxidation rate and reaction kinetics were studied and the post corroded scales were characterized in SEM, EDS and XRD. The results clearly indicate that YSZ coated specimen significantly improves the oxidation resistance as compared to uncoated specimen. The improvement of oxidation resistance in presence of YSZ coating can be attributed to the changed mechanism of scale growth from outer cation migration to inner anion migration. The detail mechanism of the oxidation behaviour in presence of YSZ coated and uncoated specimen is discussed in this paper.