Steel castings are better than iron castings. What are the characteristics of their casting process?
The most frequently heard by manufacturers is why your steel castings are not made of cast iron? Or does your family make iron castings? Many people have questions about the difference between steel castings and iron castings.
That's because the mechanical properties of steel castings are higher than that of cast iron, and they are relatively widely used in mining, building materials, forging, and hydraulic engineering. However, cast steel is not perfect either. Due to its relatively high melting point, easy oxidation of molten steel, poor fluidity of molten steel, and large shrinkage of cast steel, it is prone to defects such as insufficient pouring, cold shuts, shrinkage cavities, cracks, and sand sticking, making its casting process more complex than that of cast iron.
1. Due to the poor fluidity of molten steel, it is easy to cause cold shuts and insufficient pouring. The steel casting manufacturer requires that the wall thickness of large castings should not be less than 8MM, and the pouring system should have a simple structure and a larger cross-sectional dimension than that of cast iron.
2. "The shrinkage of the casting exceeds that of the cast iron. In order to prevent shrinkage cavities and other phenomena, the manufacturer adopts measures such as risers and chill iron in the casting process according to the casting time, to facilitate the smooth solidification of the molten steel.".
3. Why does a well produced casting require heat treatment at a later stage? That is because there are casting defects such as porosity, uneven microstructure, coarse grains, and large residual internal stress in the castings as cast, which greatly reduces the strength, plasticity, and toughness of the castings. After heat treatment, the strength, plasticity, and toughness of large castings are improved, and the service life of steel castings is also improved.