Study Of Plasma Cladded Metal-based Compound Powder Layers On Q235 Steel

In this ppaper, two kind of metal based compound powder were used to prepare alloy coatings on Q235 steel by plasma clading process. The metal based compound powder are Fe313+TiC (the TiC content respectively are 0%, 13%, 20% and 26%) and Ni60B +TiC (the TiC content respectively are 0%, 13%, 20% and 26%). The microstructure and phase composition of the alloy coating was investigated by Optical Microscope (OM), Scanning Electron Microscope (SEM), Energy Dispersion Spectroscopy (EDS) and X-ray Diffraction (XRD). The microhardness was tested by microhardness tester. The wear resistance were tested by MM-200 model friction test machine,and the wear morphologys were analyzed by image analysis system of super-hard materials, and keyence VHX-600E Digital Microscope. Effects of linear energy on microstructures and properities of coatings are analyzed by adjusting processing parameters (work current, scanning velocity), and optimize the parameters.The results showed that the cladding layers have good metallurgical bonding with the substrate, and there are not pores, cracks and other macroscopic defects in the cladding layers. The best adding amount of TiC particles in Ni60B + TiC composite powder is 20%. By using the water-cooled substrate underside and other new technology, the best amount of TiC particles (in Fe313 + TiC composite powder) is 26%. The maximum hardness value of the cladding layer is HV574, wearing capacity after 10 hours is 0.0686g. The hardness and wear resistance are better than Ni60B +20% TiC cladding layer; The TiC particles distributes in the cladding layers which is regular. Within a certain range, with the increaseing of TiC content, the microhardness of cladding layers increase, and the wear resistance greatly improve. The wear-resisting mechanism of Ni60B+TiC cladding layers are similar to Fe313+TiC layers. While the cladding layers are weared, TiC particles play the role of anti-wear skeleton. The tiny TiC particles and the fast solidification can refine crystal grain organization. C, Si, Cr and other alloying elements have merged in the crystal lattice gap to form the solid solution strengthening, and play the role of precipitation strengthens.