Gray cast iron is widely used for the cylinder bore of marine diesel engine. With the aim to improve the properties of the cylinder liner and maintain the matching ability with piston ring under the harsh working condition, the Fe-based alloy coating is fabricated on the gray cast iron using induction cladding. Owing to the high carbon content in both coating and substrate materials, it is extremely difficult to control the coating process and the coating quality. The additive of welding flux and prolonged heating time is proposed to prepare good quality coating. The coating forming mechanism is investigated, and the electrochemical corrosion and tribological properties of the coating are examined. The results show that the Fe-based coating possess better corrosive and tribological performance than gray cast iron, and it is seemed to be a potential candidate for improving the performance of the cylinder liner.

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A fully electrical-magnetic-thermal coupled model is proposed to investigate the heating mechanism of induction cladding. The simulation results reveal that the coating and the thin layer close to the substrate surface were heated layer by layer. Furthermore, the non-uniform electromagnetic field generated an uneven temperature distribution, which had a larger impact in the longitudinal direction than in the cross section. The maximum relative errors between the simulated and measured temperatures indiacate that the numerical calculation fit the experimental results well. The impact of the non-uniform temperature distribution on the coating properties was experimentally studied. The specimen in the middle position had a more complicated phase composition, lower porosity, and higher microhardness than those at the two ends.

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