manhole covers

Specifications

1 High strength: Tensile strength ó b≥420MPa,Yieid strength ó s 300MPa,the properties is the same to low carbon steel, and 3 times to gray iron materials.
2  Good toughness: The impact value is same to mid-carbon steel and 10 times over to gray iron mate rials.
3  Good plasticiey: The elongation rate ó≥7%,it is similar to high carbon steel but gray cast iron elongation is close to zero.
4  Strong Anti-corrosion: The spary water corrosion test shown that its corrosion rate is only 1/40 of the steel pipes, 1/10 of the gray iron pipes. Its use life is 2 times to gray iron pipe, 5 times to common steel pipe