Research On Fly Ash Flux And Application In Argon Arc Remelting On Permeation Layer

Using fly ash as the main raw material, fly ash composite flux is prepared on the substrate of Q235 steel by uniform design method. It consists of fly ash 94.5%, SiO₂ 0.781%. Cr₂O₃ 3.252%, NaF 1.352%, Y₂O₃0.151%. The experiment also discusses the influence of different welding currents and speeds on the penetration and width of fly ash composite flux A-TIG weld. It shows that when the welding current reaches 180A, the depth-to-width ratio reaches the maximum value of 0.57. When the welding speed reaches 125mm/s, the depth-to-width ratio reaches the maximum value of 0.54. It is observed that the fly ash composite flux could increase the weld penetration effectively under the suitable welding process parameters.On this basis, fly ash composite flux is applied to argon arc remelting technology, forming active argon arc remelting technology. The experiment is conducted by conventional argon arc remelting and active argon arc remelting on B-C-N permeation layers. It can be seen that the microstructure, phase composition and microhardness of remelted layer by two remelting processes, the active argon arc remelting can eliminate porosities and impurities, refine microstructure and improve the denseness of the layer more effectively. Conventional argon arc remelting eliminates FeB, Fe2N, FesN phase and formes Fe23?B,C?6 and Fe3N phase. Active argon arc remelting layer produces Fe2Si and Al8Fe2Si phase. The depth of hardened layer of conventional argon arc remelting and active argon arc remelting are 200?m and 360?m respectively. Active argon arc remelting's depth of hardness gradient more gentled, but its hardness is lower slightly. It can be seen from the abrasion test results that the adhesive wear coefficients of B-C-N permeability layer, conventional argon arc remelting layer and active argcrease.compare with the matrix and their adhesive wear peron arc remelting layer defor-mance increase 1.95,3.23 and 4.52 times respectively. The abrasive wear performance increase 2.77.3.76 and 3.91 times respectively. Under the different conditions of erosion wear, the erosion wear performance of B-C-N permeability layer, conventional argon arc remelting layer and active argon arc remelting layer increase 1.67-1.67,1.95-2.46 and 2.46-2.58 times, erosion wear performance in seawater increase 1.62-1.62,1.85-1.94 and 2.02-2.78 times.