A new device developed was used to spray directionally coating by wire explosion process. Stellite 6 alloy was employed to a coating deposited on a medium carbon steel in order to improve the erosion-resistance of the steel in this paper. Different initial capacitor voltages were used to prepare the coatings in the spray process. Microstructure of the coatings was examined by OM and SEM .Hardness of the coatings was measured with a hardness tester. The properties of the coatings were compared under the different wires. The results show that fine grain was found in the coating and the hardness of the coating was much higher than initial alloy hardness.