Chengdu Xinfu Shengyuan Building Materials Co., Ltd.XINFU SHENGYUAN BUILDING MATERIALS

Chengdu Ductile Iron Manhole CoverPerformance:

Ductile iron castings have been applied in almost all major industrial sectors, which require high strength, ductility, toughness, wear resistance, resistance to severe thermal and mechanical impact, resistance to high or low temperature, corrosion resistance and dimensional stability. To meet these varying service conditions, ductile iron is available in many grades, offering a very wide range of mechanical and physical properties.

As stipulated by ISO 1083, most ductile iron castings are produced in the unalloyed state. Obviously, this range includes high-strength grades with a tensile strength greater than 800 N/mm² and an elongation of 2%. The common material for ductile iron manhole covers is QT500-7, with a Brinell hardness of 170-230 HB. At the other extreme are high-ductility grades with an elongation greater than 17% and a correspondingly lower strength (as low as 370 N/mm²). Strength and elongation are not the only criteria designers use to select materials; other decisive properties include yield strength, elastic modulus, wear resistance and fatigue strength, hardness and impact properties. In addition, corrosion resistance, oxidation resistance and electromagnetic properties may be critical to designers. To meet these special applications, a family of austenitic ductile irons, often called Ni-Resist ductile irons, has been developed. These austenitic ductile irons are mainly alloyed with nickel, chromium and manganese and are included in national standards.