Comparative Study of Aluminide Coatings on Mild Steel by Different Aluminizing Techniques

摘要

Aluminizing of mild steels has been extensively studied for it's improved corrosion and oxidation resistance. A comparative study between pack aluminizing, hot dip aluminizing and spray aluminizing has been conducted and their effect on microstructures have been studied using SEM-EDX, XRD, Vickers microhardness as characterization techniques. The aluminized samples were subjected to vacuum diffusion at 830℃ for 4 hours which led to the formation of Fe_2Al_5 intermetallics. Further, the corrosion resistance of the aluminized samples has been studied using potentiodynamic test with 3.5%NaCl solution. The paper describes the properties of the coated samples as affected by the processing conditions.