EFFECT OF BURNING BIO-MASS FUEL ON THE CORROSION PERFORMANCE OF STEELS IN THE 34.5MW BOILER

Abstract

The usage of fossil fuels such as coal is now being reduced and shifted to bio-fuel in the boilers. It is because fossil fuels are exhaustible and generate CO2 emission during burning. Whereas, bio-fuels are abundantly available at low cost and also produce fewer greenhouse gases. However, burning of such fuels create a lot of corrosive species which can damage the components used for construction of boilers. Ferritic, austenitic, and martensitic steels are widely used to construct various parts of the boiler. Hence, in this study, four different grades of steels known as T91, SS304, SS316, and SS410 have been placed in the actual boiler environment for 493h. The boiler utilizes wood chips, rice husk, sawdust, bamboo base and leaf cuttings as burning fuel and operates at 850± 50[Formula: see text]C. The results indicate that T91 steel showed a maximum rate of corrosion followed by SS304, SS316, and SS410. Martensitic steel 410 showed the minimum loss in weight among other steels. No intergranular corrosion was noticed in 410 steel, but the oxide so formed on the surface was fragile and porous although the chromium content is less in SS410 as compared to SS304 and SS316.