Ductile manhole covers are currently widely used on the roads of major cities with a long service life. But what are the differences between ductile manhole cover and grey cast iron manhole cover?
1. In terms of shape, gray iron is flat and flat, while nodular graphite is spherical. In terms of sound, when tapping separately, the sound of gray iron is generally dull, and the sound of nodular graphite is similar to that of carbon steel.
2. In terms of smelting, nodular graphite is based on gray iron by adding inoculants and spheroidizing agents to make graphite change from dispersed flocs to spheroids. Gray iron manhole cover is to smelt pig iron directly into molten iron without adding any auxiliary raw materials, and then pour it into manhole cover.
3. In terms of performance, ductile manhole cover has good toughness and tensile strength: 500N/MM2; Elongation: 7%.
4. From the fracture, it can also be distinguished by the naked eye. The grain of gray iron fracture is relatively coarse, gray white, and the crystal surface has metallic luster. The fracture grain of ductile iron is very small and black gray. If the quality is good, it will be metallic luster. If the hair is white, most of it is white mouth tissue.
