| 摘要 |
A method for electro-galvanizing of cast iron, which can greatly improve corrosion resistance of cast iron by electroplating zinc on the surface of cast iron through a degreasing process, a neutralizing process, a pickling process, a galvanizing process, a chromate treating process, an alcohol treating process and a drying process, is provided. A method for electro-galvanizing of cast iron comprises: a degreasing step of dipping cast iron to be plated into an acid solution in which 10 wt.% of sulfuric acid, 5 wt.% of hydrochloric acid, 10 wt.% of surfactant and 75 wt.% of water are mixed for 15 to 20 minutes; a neutralizing step of washing the cast iron with water and dipping the washed cast iron into a 5% aqueous sodium silicate solution for 15 to 20 minutes to neutralize acid components remaining on the cast iron; a pickling step of washing the neutralized cast iron with water again and dipping the washed cast iron into a 5% sulfuric acid solution for 5 to 7 minutes to pickle the cast iron; a galvanizing step of washing the pickled cast iron using water, and electro-galvanizing the washed cast iron in a plating tank filled with a plating solution prepared by mixing 200 g/L of ammonium chloride with 50 g/L of zinc chloride for 25 to 30 minutes; a chromate treating step of washing the galvanized cast iron with water, and treating the washed galvanized cast iron with colorless chromate for 20 seconds; an alcohol treating step of washing the chromate treated cast iron, and treating the washed cast iron with alcohol; a drying step of drying the alcohol treated cast iron at 55 to 60 deg.C for 10 to 15 minutes; a product inspecting step of inspecting the plating state of the dried cast iron; and a packing step of packing the inspected cast iron.
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