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The subject adopts the CO 2 laser, ductile iron as a substrate, novel coating materials alloying experiment. Research laser alloying appropriate process parameters and influencing factors, and independently developed laser alloying coating to achieve the desired strengthening effect. By scanning electron microscopy (SEM), EDAX can spectrometer (EDS), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM) analysis and testing by means of the alloyed layer microstructure and physical form were analyzed , and the alloyed layer hardness and friction performance test. Grade HG0 3 of new paint, changing the laser scanning speed (400mm/min-1000 mm / min) of ductile cast iron laser alloyed experimental research in the coating material under certain conditions, laser scanning speed alloyed layer microstructure and properties. Found with the laser scanning speed increases, the alloyed layer tissue gradually dense refinement, the dendrite arm spacing, the hardness and wear resistance of the alloy layer also rise. In the present experimental conditions, when the laser power P = 3kw, the spot diameter D = 5mm, preferably by laser scanning speed of 1000 mm / min, preferably obtained by laser alloyed layer performance. In the laser processing parameters under certain conditions, the use of grades HG0 3 , HG0 1 , TH 2 A, AY coating experiment laser alloyed found HG series and TH of 2 A coating prepared by laser alloying layer surface is relatively flat, AY coatings prepared alloyed layer surface morphology poor. And HG series coatings prepared alloyed layer hardness and wear resistance are better. In HG0 1 coatings based on research and development HG0 3 coating alloyed layer has a minimum coefficient of friction and the lowest amount of wear exhibited excellent friction and wear properties, the wear rate of the minimum only substrate ductile iron wear rate of 1/9. The new carbide Add microhardness and wear resistance of the alloy layer have been significantly improved. Wherein the ceramic hard phase content of 0% of the amount of wear of the alloyed layer is significantly greater than the content of 20%, 30%, 40% of the alloyed layer, but with the ceramic hard phase content increases, no significant changes in the amount of wear, ceramic The hard phase content of 20%, 30%, 40% of the laser alloyed sample wear rate are approximate 1/10 of the substrate ductile iron wear rate. HG series of new paint in the practical application of detection the water Steel and Tangshan processing station. The water steel rebar roll HG0 3 type alloy coatings processing, blooming and rolling life expectancy has increased by 120%. Using HG0 3 coating in Tangshan processing station on H-beam laser surface alloying processing, finishing, life expectancy has increased 110%.
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