Experimental investigation of laser cladding of H13 hot work steel by Stellite 6 powder

Abstract

Cladding of metals can enhance the wear behavior of metals. Many dies work at elevated temperature such as hot forging dies and hot extrusion dies needs resistance to wear at higher temperatures. In this article, the cladding of H13 hot work steel (DIN 1.2324) will be investigated by laser cladding. The Stellite 6 powders coat the steel surface by using a continuous fiber laser. Two important objects in cladding are the effect of laser process parameters on the quality of the cladding layer and the lateral overlapping percent in adjacent passes. The laser power, scanning speed, and powder feed rate are the process variables in the study. The results show that the laser power is the most influencing parameter and by increasing laser power and decreasing the scanning speed, the hardness and penetration depth of cladded powder in the substrate will be increased. The dilution factor increases by increasing the laser power and reducing scanning speed at a moderate powder feed rate. The microstructure observation shows that strong metallurgical bonding between the clad and substrate and good mixing of powder in substrate metal can be obtained by proper setting of process parameters. The micro-hardness of the cladded specimen increased 300 HV (164 % increase compared to the substrate material. Best results were obtained at 10 % overlapping between adjacent irradiation passes.