Ductile iron manhole covers are one type of ductile iron products. Ductile iron obtained Spheroidal graphite through ball and bred deal, which effectively improve the mechanical properties of cast iron , especially improve the ductility and toughness , resulting in higher strength than carbon steel . Ductile iron was developed a high-strength cast iron materials in the 1950s. its overall performance is close to steel. Based on its excellent performance ,Ductile iron has been successfully used to cast some of the complex force , strength, toughness, wear require a higher parts. Ductile iron has been behind the rapid development of gray cast iron widely used . The so-called ” Replace steel with iron ” , mainly referring to ductile iron.In now market,many factories are producing ductile iron manhole covers.
Ductile iron manhole covers features:
- Good toughness. Impact value of carbon steel with a detailed, is 10 times more gray iron material.
- Corrosion resistance. Spray corrosion test, the ninety days corrosion of steel is only 1/40. Life is two times more than gray iron pipe ,5 times more than ordinary steel pipe.
- Good plasticity. Elongation ≥ 7%, with a similar high-carbon steel, gray iron material and elongation zero.
- High strength. Tensile strength ób ≥ 420MPa, yield strength ós ≥ 300MPa, and the same low-carbon steel, gray iron material three times.