Effect of Output Conditions on Microstructure and Properties of SKD61 Laser Cladding

This study investigated the effect of cladding on tool steel (SKD61) by using 5%Cr-1.5%Mo-Fe powder (SKD61), which is expected to be economically effective when used to manufacture and mend die-casting parts. The cladding conditions were as follows: the distance between the coaxial powder supply head and the substrate surface was 20 mm, and Ar was used as the supply gas. The laser outputs applied in the cladding procedure were 3, 4, and 5 kW. The microstructure of the heat-affected zone in the processed specimens was analyzed, and the macrostructure and morphology of the substrate material were studied. Specimen hardness measurements were performed at intervals of 0.1 mm from the substrate surface to the core. As the laser output increased from 3 to 4 and 5 kW, the dilution rate increased from 10.6% to 11.8 and 13.2%. It was confirmed that the fraction of carbides increased as the laser output increased from 3 kW to 5 kW.