Inspection and treatment before pickling: check whether the iron work piece has the galvanized process hole of the factory (exhaust, zinc in and out, hanging), the degree of corrosion on the surface of the iron work piece, and whether the surface cover can be removed by hydrochloric acid (if there is paint, grease, etc., it shall be removed by fire, grinding, alkali washing, etc.).
Degreasing (alkaline washing): equipped with heating equipment to eliminate grease, coating, etc. on the surface of iron workpieces.
Water washing: remove alkaline water and attachments on the surface of iron work pieces.
Pickling: remove rust, scale and other surface coverings
Inspection and treatment after pickling: whether the pickling effect is ideal. If the pickling is not sufficient, pickling shall be carried out again. If the treatment before pickling is not complete, pickling shall be carried out again after re treatment.
Apply plating aid: clean the workpiece surface again to ensure that the surface is not rusted before galvanizing.
Drying: raise the temperature of wrought iron workpiece to avoid excessive moisture on the surface of wrought iron and explosion during galvanizing.
Hot dip galvanizing: the workpiece is immersed in molten zinc at 440 ℃ - 470 ℃ and put forward after a certain time. A layer of zinc iron alloy layer and pure zinc layer are obtained on the surface of iron workpiece.
Passivation: provide atmospheric corrosion resistance of workpiece surface, reduce or prolong the time of white rust.
Cooling: prevent the workpiece from chilling and retracting, resulting in collective tissue cracking.
Finishing: remove zinc nodules and zinc dust attached to the coating surface
Inspection: Inspection and measurement of coating and appearance inspection of workpiece.
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