... high quality, anti-corrosion. Product Description Ductile Iron Casting Pipe Material: Ductile iron Guangxi Yuehan Trading Co., Ltd is a ... easy connection; (7) High strength, lighter than gray iron, good corrosion resistance, small flow resistance, easy fixing, ... Procedure: (I) Smelting and Nodulizing (II) Centrifugal Casting (III) Annealing Treatment (IV) Zinc Spraying for Corrosion Resistance (V) ...