Jinmai Malleable Iron: Unveiling the Complete Production Process of Malleable Iron Pipe Fittings
A high-quality malleable iron pipe fitting requires dozens of rigorous and meticulous production processes from raw materials to finished product. Hebei Jinmai Malleable Iron Co., Ltd. employs a modern, standardized, and intelligent production process, with each process meticulously crafted and strictly controlled to ensure superior product quality. The first step is automated sand molding. The company has introduced a high-precision automated molding production line, using precision molds as a benchmark to create sand molds with accurate dimensions and uniform compactness. This ensures that the pipe fitting blank has a regular shape and smooth inner cavity, eliminating problems such as dimensional deviations, blank deformation, and burrs caused by traditional manual molding, laying the foundation for subsequent processing.
The second step is high-temperature smelting and casting. Selected high-quality malleable cast iron raw materials are put into an energy-saving electric furnace and smelted at temperatures above 1400℃ into pure molten iron. Impurities are removed through professional slag removal and degassing processes to ensure the purity of the molten iron. Then, automated casting equipment is used to precisely pour the molten iron into the sand mold, controlling the casting speed and temperature to ensure the blank is formed completely, without porosity or shrinkage. The third step is core graphitization annealing. The cooled blank is sent to an intelligent annealing furnace, undergoing three stages: high-temperature heating, constant-temperature holding, and slow cooling, to complete the graphitization annealing treatment. This eliminates internal stress in the blank, transforming brittle white cast iron into malleable cast iron with excellent toughness. This is a key process determining the performance of malleable iron pipe fittings. The fourth step is sandblasting and finishing. The annealed blank undergoes sandblasting and cleaning to remove surface impurities and oxide layers. Then, CNC equipment is used for grinding and turning to correct dimensions and remove burrs, ensuring the appearance and dimensional accuracy of the pipe fittings. The fifth step is hot-dip galvanizing for corrosion protection. The precision-machined pipe fittings undergo degreasing, pickling, zinc immersion, and passivation to form a uniform and thick anti-corrosion zinc layer. Finally, precision thread machining and full inspection are performed. Standard threads are machined using a CNC thread lathe, and after 100% passing all quality inspections, the fittings are packaged and stored. This combination of full-process automation and meticulous manual control ensures that every product meets process standards and achieves outstanding quality.
Post time: Jun-24-2026