Process parameters optimization of single-track laser cladding for 45 steel gear remanufacturing

Abstract

In order to research the optimal combination of process parameters for the remanufacturing of 45 steel gear with RCF104 alloy powder, three-factor and five-level orthogonal experiments of laser power, scanning speed and powder feeding speed were carried out on 45 steel substrate. The best process parameters combination was selected by considering the shape coefficient of the cladding layer, dilution rate, cladding width and cladding height. The microstructure of the cladding layer was analyzed, the horizontal and vertical microhardness of the cladding layer was measured. The results show that the optimal combination of process parameters was laser power 448 w, scanning speed 6 mm/s, powder feeding speed 9.0369 g/min. The analysis of variance shows that the laser power and scanning speed were the main factors influencing the cladding width and the scanning speed had a significant influence on the cladding height and shape coefficient. The microstructure analysis of cladding layer shows that planar crystals, cellular crystals, columnar crystals, dendrites and equiaxed crystals changed gradually from bottom to top. The average microhardness of the cladding layer was 672.2HV, which was 3.08 times of the matrix hardness.