Cast iron manhole cover

Good toughness. The impact value of medium carbon steel is detailed, which is more than 10 times that of gray iron material. Strong corrosion resistance. Water spray corrosion test shows that the corrosion amount in 90 days is only 1/40 of that of steel pipe and 1/10 of that of gray iron pipe. The service life is twice that of gray iron pipe and five times that of ordinary steel pipe. Good plasticity. The elongation is ≥7%, which is similar to that of high carbon steel, while the elongation of gray iron material is zero. High strength. Tensile strength ób≥420MPa, yield strength ós≥300MPa, which is the same as low-carbon steel and three times that of gray iron material. Because of its spherical graphite microstructure, ductile iron is superior to cast steel in reducing vibration, so it is more conducive to reducing stress. An important reason for choosing ductile iron is that the cost of ductile iron is lower than that of cast steel. The low cost of ductile iron makes this material more popular, with higher casting efficiency and less machining cost. The strength of nodular cast iron is comparable to that of cast steel. Ductile iron has a higher yield strength, the lowest yield strength is 40k, while the yield strength of cast steel is only 36k. In most municipal applications, such as water, salt water, steam, etc., the corrosion resistance and oxidation resistance of ductile iron exceed that of cast steel.ation resistance of ductile iron exceed that of cast steel.