Heavy Duty Ductile Iron Manhole Cover

The ductile iron manhole cover is mainly made of ductile iron, or often called nodular iron. The quality depends on the nodularity. Anti-rust asphalt paint is commonly used in the casting process. In other words, the surface of ductile iron manhole covers are generally sprayed with asphalt for anti-rust treatment. Features of ductile iron manhole cover: 1. High strength The tensile strength of ductile iron is greater than 420Mpa; the yield strength is greater than 300MPa. Same as low carbon steel, it is more than 3 times that of gray iron. 2. Good toughness. The impact value is similar to that of carbon steel and 10 times that of gray iron. 3. Good plasticity. The elongation rate is greater than 7%, which is similar to high-carbon steel and gray iron materials. 4. Corrosion resistant. In the 90-day spray corrosion test performance of ductile iron, the corrosion was only 0.25 times that of pipelines and 0.1 times that of gray cast iron pipelines. The service life is 2 times longer than gray cast iron pipes and 5 times longer than ordinary steel pipes. In most municipal applications, such as water, salt water, steam, etc., the corrosion and oxidation resistance of cast iron exceeds that of steel. Due to the microstructure of spherical graphite cast iron, nodular graphite cast iron is better than steel in reducing vibration capabilities. Advantages of ductile iron manhole cover: 1. Low cost Low cost is an important reason why cast iron is more acceptable than steel, which makes ductile iron more popular. The casting efficiency is higher, and the processing cost of ductile iron is lower. 2. Lightweight There is another advantage of ductile iron manhole covers. Ductile iron has high strength and toughness, which makes ductile iron manhole covers 30% lighter than similar manhole covers made of gray cast iron.