Role of Coating in Improving High Temperature Oxidation of Steel

<p>Oxidation is the major degradation mechanism of failure for various components operating at high temperature. Protective coatings are used to improve the oxidation resistance of such component. In the present investigation, Al2O3 and Ni-20Cr coatings have been deposited on SAE431 boiler steel by Detonation Gun Spraying Method. The oxidation performance of Al2O3 and Ni-20Cr coated as well as uncoated SAE-431 steel has been evaluated in air under cyclic conditions at an elevated temperatures of 8000C. Al2O3 coating on SAE431 boiler steel has shown approximately 26% improvement in the oxidation resistance of SAE431 steel whereas Ni-20Cr coating on SAE431 boiler steel has indicated about 21% improvement in the oxidation resistance as compared to the uncoated SAE431 boiler steel.