Product Introduction:
Graphite iron is a type of cast iron, an alloy of iron, carbon, and silicon. The graphite in graphite iron exists in spherical form, usually with a size of 6-7 grades. In terms of quality, the spheroidizing grade of the cast pipe is required to be controlled at 1-3 grades (spheroidizing rate ≥80%), thereby significantly improving the material's mechanical properties, combining the essence of iron with the performance of steel. After annealing, the microstructure of the graphite iron pipe consists of ferrite with a small amount of pearlite, and it has good mechanical properties.
Ductile iron pipe features:
■ Possesses the essence of iron and the properties of steel, with excellent corrosion resistance and good ductility. Easy to install, mainly used for municipal, industrial, and mining enterprises for water supply, gas transmission, and oil transportation.
In medium and low-pressure pipelines, ductile iron pipes offer reliable operation with low failure rates and specific execution standards for construction and maintenance.
The main constituents of ductile iron pipes include carbon, silicon, manganese, sulfur, phosphorus, and magnesium, among others.
Ductile iron pipes, as a new type of piping material, exhibit excellent performance characteristics: superior mechanical properties, metal savings; easy construction, cost-effective overall project cost, high reliability, corrosion resistance, safe water and gas supply; used in water supply pipelines, water distribution networks, oil transportation pipelines and networks, gas transportation pipelines and networks, with a long service life. Ductile iron is an alloy of iron, carbon, and silicon, where carbon exists in a spherical free graphite form. In gray cast iron, the flake-shaped graphite exerts a "cutting" effect on the iron matrix, making it brittle. In ductile iron, the spherical graphite eliminates this destructive action, making it tough. It retains the essence of iron and the properties of steel.
Graphite cast iron and gray cast iron both contain graphite units, meaning cast iron is a mixture of iron and graphite. In gray cast iron, the graphite is in a flake form, with very low strength, resulting in numerous flake-like voids within the cast iron, thus making it relatively weak and brittle. In graphite cast iron, the graphite is spherical, creating many spherical voids within the cast iron. Spherical voids have a far lesser impact on the strength of cast iron compared to flake-like voids, which is why ductile iron is much stronger than gray cast iron. Naturally, high-strength ductile iron pipes are highly popular!
Ductile iron pipes have become the preferred material for water supply systems worldwide and are increasingly being adopted in gas pipeline systems. This is due to the fact that ductile iron pipes possess the strength and required elongation of steel pipes, but offer corrosion resistance that is twice as good. Flexible joints effectively reduce vibration.
Ductile iron pipes, renowned for their superior mechanical properties and quality, are the pillars of the pipeline water supply industry. With their exceptional pressure-bearing capacity, reliable sealing performance, unparalleled anti-corrosion treatment, and guaranteed water quality system, they ensure near-perfect water supply even under complex terrains such as saline-alkali soils, swamps, steep slopes, and deserts, where balanced soil conditions are prevalent.
Ductile iron pipes have tensile strength and pressure resistance comparable to steel pipes, with significantly higher elongation than gray cast iron pipes, offering excellent toughness. They not only overcome the vulnerability of gray iron pipes to fracture but also avoid the negative phenomenon of steel pipes deforming under high pressure. Consequently, ductile iron pipes exhibit remarkable seismic resistance and significantly extended service life, up to 50-70 years.
Ductile iron pipes (hereinafter referred to as DIP) are the most widely used water supply pipes internationally and are also applicable in the oil, power, mining, and chemical industries. DIP combines the corrosion resistance of gray iron pipes with the strength and toughness of steel pipes, weighing 1/3 to 1/2 less than gray iron pipes of the same diameter, closer in weight to steel pipes. However, its corrosion resistance is several to even tens of times higher than that of steel pipes, making special corrosion protection unnecessary in various environments. The strength of DIP is sufficient to bear complex external loads, including road loads, a feature far superior to gray iron, cement, glass, and plastic pipes. The cement lining, after being polished, has a very low roughness coefficient, resulting in minimal fluid resistance, which is comparable to glass and plastic pipes.
