Production process of mechanical properties of ductile iron manhole cover

Ductile iron castings have been applied in almost all major industrial sectors, which require high strength, plasticity, toughness, wear resistance, severe thermal and mechanical impact resistance, high or low temperature resistance, corrosion resistance, and dimensional stability. In order to meet these changes in usage conditions, there are many grades of ductile iron available, providing a wide range of mechanical and physical properties.

As specified by the International Organization for Standardization ISO 1083, most ductile iron castings are mainly produced in a non alloy state. Obviously, this range includes high-strength grades with a tensile strength greater than 800 Newton/millimeter and an elongation of 2%. The other is a high plasticity grade with an elongation rate greater than 17%, while the corresponding strength is lower (with a minimum of 370 Newton/millimeter).

Strength and elongation are not the materials chosen by designers, and other decisive important properties include yield strength, elastic modulus, wear resistance and fatigue strength, hardness, and impact performance. In addition, corrosion resistance, oxidation resistance, and electromagnetic performance may be crucial for designers. In order to meet these special needs, a set of austenitic ductile iron, commonly known as AoNi Resis ductile iron, has been developed. These austenitic nodular irons are mainly alloyed with zinc, chromium, and manganese and are listed in international standards.