Cladding is an alloy layer that is superior in abrasion resistance by spraying, overlay welding, laser cladding or the like on its surface in case of abrasion due to repeated abrasion, impact, corrosion. Laser cladding is a process in which a clad material and a part of a substrate are melted with a high power laser beam to form a coating layer completely metallurgically bonded to the substrate. In this study, laser cladding was performed using Co-based LC-190 alloy powder for hard facing of ship exhaust valve. One-pass cladding was performed by varying the preheating temperature, laser output and beam feed rate of the base material using a diode laser with a maximum output power of 8.0 kW. The shape, dilution rate, Characteristics were observed. As a result, defects could be suppressed by applying preheating, and as the heat input increased, the width of the clad layer increased and the height decreased. In addition, the average hardness value was gradually decreased as a result of hardness measurement, and it was found that dilution was increased by EDS component analysis.

Laser cladding is a process in which metal powder and wire are melted to form a cladding layer using a laser heat source to prevent material and surface from abrasion and corrosion. Since the dissimilar metal to be added is fusion bonded at the interface, the base material is partially dissolved to form a mixed melt bonding layer, whereby the thickness and composition of the bonding layer affect the physical properties of the base material and the clad layer. At this time, dilution of the added metal and the base material is preferably limited to a very small amount. Such laser cladding has been put to practical use in exhaust valves of ship industry, turbine blades and machine parts in the field of power generation facilities, and is expected to be put to practical use in the defense industry and aerospace industry. In this study, multi-pass cladding was performed by varying the superposition ratio and the powder feed rate using a diode laser and a powder feeding method with a maximum power of 8.0 kW, and the difference of the cladding layers was compared and analyzed. As a result, as the overlap ratio increased, the width decreased and the height increased. Also, it was found that the height of the clad layer increased as the powder feed amount increased, but cracks occurred when the feed amount was excessive, and a proper powder feed amount was required.