Characteristics of Ductile Iron Manhole Covers

1. Good toughness: The impact value is similar to that of medium carbon steel, more than 10 times that of gray iron material.

2. Strong corrosion resistance: In the water spray corrosion test, the corrosion amount in 90 days is only 1/40 of the steel pipe and 1/10 of the gray iron pipe. Its service life is 2 times of that of gray iron pipe and 5 times of that of ordinary steel pipe.

3. Good plasticity: Elongation ≥ 7%, similar to that of high carbon steel, while the elongation of gray iron material is zero.

4. High strength: The tensile strength ó b ≥ 420MPa, and the yield strength ó s ≥ 300MPa, which are the same as low-carbon steel and three times of gray iron materials.