Cast iron covers are divided into manhole covers and gray cast iron manhole covers.In general, the same weight of ductile iron covers gray iron manhole covers than strong compression capabilities. Material gray iron manhole covers employ generally HT200. It covers the use of ductile materials generally QT500-7.

Ductile iron manhole covers 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 coating paint the asphalt. Of course, the surface of manhole covers is through asphalt paint spray 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.

Feature

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. Therefore more conducive to reducing stress. Choose a ductile iron main reason is due to the ductile lower cost than steel. 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.

Applications

Municipal roads, highways, telecommunications, electricity, water, community, schools and other parks.