Method for producing enamel nodular graphite cast iron

The invention relates to a production method for enamel ductile cast iron pipe, particularly suitable for producing ductile cast iron water supply pipe with flange; the invention aims to extend the service life of the enamel ductile cast iron pipe, beautify the appearance, and make the enamel ductile cast iron pipe non-toxic and sterile. The method comprising the following steps: soaking cleaning with aulfuric acid solution and then drying; preparing ground coat and surface glaze respectively to spraying, putting a ductile cast iron pipe into a enamel stove, and tapping after high-temperature sintering; and naturally cooling.