| This dissertation concentrates studies of fly ash, which was provided by Fuxin Mineral Group, as well as feasibility of activating flux in the preparation of argon arc welding. Morphologies, cross-sections,micro-structures were compared respectively, and optimized fly ash activating flux was acquired by the adulteration of SiO2 and Al2O3. By analyzing the distribution of Si, Al in molten bath, mechanism of A-TIG was predicted. Statistics show that depth of A-TIG welding beam can be improved from 2.19 mm to 3.66 mm after putting fly ash as activating flux, and its width contracted from 9.88 mm to 8.39 mm. Welding depth increased remarkably when SiO2 was adulterated, and its depth peaked at maximum 6mm, whereas adulteration of Al2O3 does not improve welding depth remarkably.Above these work, then activating flux were used to prepare Activating flux-Tungsten Inert Gas cladder. Morphologies, cross-sections, micro-structures, XRD, micro-hardness and wear resistance, corrosion-resistance, and erosive wear resistance were analyzed. Results show that Fe2B, Fe3B can be found in cladder prepared by conventional welding, hardness of the layer is about 300HV, wear resistance was improved to 1.98 times, corrosion-resistance were improved to 2.27 times and 1.92 times respectively, erosive wear resistance ranged from 1.23-2.5 times; New phases such as Fe3.5B and Fe23(C,B)6 can be found in cladder prepared with fly ash, the hardness of the layer is about 350HV, wear resistance was improved to 2.15 times, corrosion resistance were improved to 4.56 times and 1.95 times respectively, erosive wear resistance ranged from 1.28-4.7 times; Other new phases like Fe2AlB2 and Fe3Al2Si3 can be found in cladder prepared by adding 40% SiO2 to fly ash, the hardness of the layer is about 400HV, wear resistance was improved to 2.33 times, corrosion-resistance were improved to 4.26 times and 2.31 times respectively, erosive wear resistance ranged from 1.30 to 6.46 times. |
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