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• Rizhao steel released its HRC • Stainless steel capacity to hi • Contractors invited to submit • global production of ductile i • Ductile iron pipe construction

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Name: Mr. Muhammad
Tel: 0086 531 86931898
Add: No.29 Luoyuan Street, Jinan China


Why Ductile Iron

Ductile Iron, also known as nodular iron, was developed in 1949 as a substitute for steel. Cast steel contains carbon of less than .3% by weight, while cast and ductile irons have at least 3% total carbon. This low carbon content in cast steel does not allow the carbon to form as free graphite resulting in a laminate type of structure. The natural form of carbon in cast iron is the free graphite flake form. In Ductile Iron, this graphite flake is modified by a specialized treatment process to form tiny spheres or nodules. These modified graphite nodules provide Ductile Iron with physical properties greater than cast iron and comparable to steel. It is this nodular microstructure of carbon in Ductile Iron which produces high ductility and shock resistance while the flake form of cast iron results in no malleability. Optimum ductility is obtained with a ferritic matrix, therefore, all NIBCO’s Ductile Iron pressure containing parts are reated with a ferritizing annealing cycle. In Ductile Iron spheroidal nodules also eliminate the crack effect of flake graphite which is exhibited in cast iron. In microscopic photos of Ductile Iron, cracks can be seen traveling to a graphite nodule and stopping. These graphite spheroids are know as “crack arresters” in the Ductile Iron industry because of their ability to stop cracks in their tracks.

In some circles, Ductile Iron is known as the metal that is the best of both worlds” meaning that Ductile Iron combines the superior strength of cast steel with the excellent corrosion resistance of cast iron. Ductile Iron vs. Cast (Gray) Iron The strength of Ductile Iron when compared to cast iron is overwhelming. Ductile Iron tensile strength is 60k versus cast iron at 31k. Ductile Iron has a yield strength of 40k, whereas cast iron exhibits no yield, only ultimate fracture. Ductile Iron strength-to-cost ratio offers greater value for a marginal increase in cost over cast iron. (See page 83 for a complete comparison of mechanicals.) Ductile Iron offers excellent corrosion resistance that is equivalent to cast iron.

Ductile Iron vs. Cast Steel

The strengths of Ductile Iron and cast steel are comparable. Ductile Iron has a higher minimum yield strength at 40k versus cast steel at 36k. (See page 83 for a more complete comparison of mechanicals.) Ductile Iron has corrosion and oxidation resistance that surpasses cast steel in most general utility service applications, i.e. water, saltwater, steam. Because of Ductile Iron’s spheroidal graphite microstructure, Ductile Iron is superior to steel in its ability to deaden vibration and therefore reduce stresses. An important factor in selecting Ductile Iron over cast steel is cost. The lower expense of Ductile Iron results from readily available materials, foundry operation efficiencies and reduced machining costs of Ductile Iron.

Why choose ductile iron pipe

In building construction, especially in the construction of urban water supply pipeline network requires the use of its pipeline products have high strength, high toughness, high corrosion resistance and the construction and installation of integrated cost and other factors. From the point of view, is undoubtedly the best choice for ductile iron pipe, ductile iron pipe from the production process to the final construction and installation are in compliance with our requirements.
Ductile pipe installation and construction in today's large projects in the city can be well known industry experts said. Even say, no matter how complex the project, select the ductile iron pipe products as the main pipeline is absolutely a wise choice for long-term cost-effective.