Gray iron castings cast hard, what does it matter

Gray cast iron, also known as gray cast iron, has graphite flakes. Due to the existence of flake graphite, the metal matrix structure is cut the effective area of the load is reduced, so its comprehensive mechanical properties are low, but its vibration damping, wear resistance, casting cutting machinability are better. If there is a problem of immobility during processing, the following inspection rescue methods can be taken:

1. It is necessary to check the chemical composition to see if the content of manganese is high. If the content of manganese is high, the surface of the gray iron casting will be hard.

2. 2. The casting thin-wall cooling will quickly produce problems such as white mouth, it will also cause the gray iron casting to be hard to process.

3. Due to the high hardness of the gray iron casting itself, the choice of cutting tools should be reasonable. G8 is used to the tool for roughing, G6 is used for semi-finishing, G3 is used for finishing. It can't be processed with cubic boron nitride CBN tool, it can be processed in hardness DRC60. It is also necessary to correctly the speed feed.

4. Tempering treatment can only eliminate the rigidity of the casting itself, but also reduce the hardness of the casting to facilitate processing.