Microstructure and properties of WC-4Co ESD coating of cast steel roll

WC-4Co electrode material is deposited on the surface of cast steel roll by electro-spark deposition(ESD).The microstructure and wear resistance of the coating are investigated.The results show that the coating consists of Fe₃W₃C,Co₃W₃C,Fe and SiC phases,and the coating bonded with cast steel roll substrate is well metallurgical.The phases of Fe₃W₃C and Co₃W₃C distribute dispersedly in the coating with the extra-fine structure.The average hardness of the coating is 1 617.2 HV.The resistance performance of the coating is 2.1 times higher than that of the cast steel substrate.The wear mechanism is adhesion wear,fatigue wear,oxidization wear and abrasive wear,but the main wear mechanism is fatigue wear and abrasive wear.