Microstructural and Physical Properties of a nickel-Chromium alloy Powder laser alloyed onto a 45 steel surface
X-W. Qiu, Y-P. Zhang and C-G. Liu
The alloying treatment was carried out by CO2 laser on 45 steel surface, the microstructure and physical properties of the alloyed layer were researched by means of scanning electron microscope (SEM) with energy dispersive spectrum (EDS) analysis, metallographic microscope, X-ray diffraction (XRD), microscopic Vickers hardness tester, electrochemical workstation, etc. The results indicate that the coatings of the laser alloyed layer were constituted by the alloying zone, the bonding zone and the heat affected zone (HAZ). The combination between the coating and substrate is metallurgical. Cr3C2, FeNi3, Cr23C6, Fe3C were that main phases appearing in the alloyed layer. The microhardness of the laser alloyed layer was 1056 Hv and the corrosion resistance performance also increased. The increase in scanning speed was also seen to improve the corrosion resistance.
Keywords: CO2 laser, laser alloying, nickel, chromium steel, microstructure, metallurgical bonding, microhardness, corrosion resistance