In this study, S50C steel was hot dipped into molten Al–Fe alloy with different Fe content; when the Fe content exceeded 23 wt.%, the hot-dip coating on S50C steel cannot be achieved due to lack of wetting. Using Vicker’s hardness, vane-on-disc wear, and laser specular reflection tests, the Al–23-wt.% Fe alloy hot-dip coating showed high hardness, wear resistance, and surface glossiness. CLSM, SEM, and EDS were used to observe the interface reaction between S50C steel and the hot-dipped Al–23wt.% Fe alloy after an annealing treatment at 650°C–850°C. Because Fe could not diffuse into the Al–23-wt.% Fe alloy, the Al–23-wt.% Fe alloy had no interfacial reaction layer; only the S50C steel formed the Fe3Al intermetallic compound during the thermal activation reaction (activation energy = 253 kJ mol−1). Further, it was found that annealing temperatures of >850°C prevented the formation of Fe3Al intermetallic compound due to the diffusion of carbon into the cast-welding layer.
The International Journal of Surface Engineering and Coatings