Carrying Capacity Heavy ductile iron manhole over in the safety factor when 9 is 400KN. In fact, on the cover of the treatment process issues. Bearing type mainly in the main structure in order to achieve the main parameters of the requirements but also reduce the weight and volume of the production process was designed to strengthen the tendons and other methods. The heavy-duty ductile iron material itself mainly indicators meet the parameters required. The simplest explanation is that mechanical optimization.

Heavy ductile iron manhole over mainly the build out of the covers. This covers on their quality involves the question of the rate of the ball. Casting process is commonly used in anti-rust paint asphalt paint, of course, ductile iron manhole cover surface is asphalt paint after spraying anti-rust treatment. Manhole covers have the advantage that due to the high ductile strength, good toughness. So ductile than covers the same type of gray cast iron manhole covers about 30% lighter.

Heavy ductile iron manhole over features:

Good toughness. Impact value and carbon steel exhaustive, is 10 times more gray iron material.

Corrosion resistance. Spray corrosion test, the amount of corrosion of steel is only ninety days of 1/40, 1/10 gray iron pipe. Life is twice as gray iron pipe, steel pipe is five times the ordinary.

Good plasticity. Elongation ≥7%, with similar high-carbon steel, and gray iron material elongation zero.

high strength. Tensile strength ób≥420MPa, yield strength ós≥300MPa, and low-carbon steel and is three times gray iron material.

Since the microstructure of spheroidal graphite ductile iron, weakening vibration capability, ductile than steel, and therefore more conducive to reducing stress. One important reason is that the choice of ductile iron cast ductile lower than cost. Ductile Iron low cost makes this material more popular. Casting more efficient, less ductile iron machining costs.

Strength and intensity of cast ductile iron are comparable. Ductile iron has a higher yield strength. Minimum yield strength of 40k. The yield strength of steel is only 36k. In most municipal applications, such as: water, salt water and steam. Ductile iron corrosion resistance and oxidation resistance than steel.