The processing characteristics of stainless steel precision casting:
1. Due to the fact that the shrinkage of stainless steel precision casting greatly exceeds that of cast iron, in order to prevent shrinkage and porosity defects in castings, measures such as risers, cold iron, and subsidies are mostly used in the casting process to achieve sequential solidification.
To prevent shrinkage, porosity, porosity, and crack defects in stainless steel castings, the wall thickness should be uniform, sharp corners and right angle structures should be avoided, sawdust should be added to the mold sand, coke should be added to the core, and hollow cores and oil sand cores should be used to improve the yielding and breathability of the sand or core.
2. Due to the poor fluidity of molten steel, in order to prevent cold shuts and insufficient pouring of steel castings, the wall thickness of steel castings should not be less than 8mm; Adopting dry casting or hot casting; Increase the pouring temperature appropriately, usually between 1520 ° C and 1600 ° C, because the pouring temperature is high, the superheat of molten steel is high, and the liquid state is maintained for a long time, which can improve the fluidity. However, if the pouring temperature is too high, it can cause defects such as coarse grains, hot cracking, porosity, and sand sticking. Therefore, for precision castings with small, thin-walled, and complex shapes, the pouring temperature is approximately the melting point temperature of steel+150 ℃; The structure of the pouring system should be simple and the cross-sectional size should be larger than that of cast iron; The pouring temperature of large, thick walled castings is about 100 ℃ higher than their melting point.