The casting measures for stainless steel pipe fittings are
1. Since the shrinkage of stainless steel pipe fitting casting is much greater than that of cast iron, to prevent shrinkage cavities and shrinkage porosity defects in castings, measures such as risers, cold iron, and subsidies are mostly used in the casting process to achieve sequential solidification.
2. To prevent shrinkage cavities, shrinkage porosity, pores, and cracks in stainless steel pipe fittings, the wall thickness should be uniform, avoid sharp corners and right-angle structures,add sawdust to the casting sand,add coke to the core, and use Hollow cores and oil sand cores are used to improve the concession and air permeability of sand molds or cores.
3. Due to the poor fluidity of molten steel, to prevent cold insulation and insufficient pouring of steel castings, the wall thickness of steel castings cannot be less than 8mm; use dry casting or hot casting, and increase the pouring temperature appropriately, generally1520~1600C, because the pouring temperature is high, the superheat of the molten steel is large, the liquid state can be maintained for a long time, and the fluidity can be improved. However, if the pouring temperature is too high, it will cause defects such as coarse grains, thermal cracks,pores, and sand sticking.Therefore,for general small, thin-walled,and complex-shaped precision castings, the pouring temperature is about the melting point temperature of steel +150C. The structure of the pouring system should be simple and the cross-section size should be larger than that of cast iron. The pouring temperature of large, thick-walled castings should be higher than that of cast iron. Its melting point is about 100℃ higher.
2. To prevent shrinkage cavities, shrinkage porosity, pores, and cracks in stainless steel pipe fittings, the wall thickness should be uniform, avoid sharp corners and right-angle structures,add sawdust to the casting sand,add coke to the core, and use Hollow cores and oil sand cores are used to improve the concession and air permeability of sand molds or cores.
3. Due to the poor fluidity of molten steel, to prevent cold insulation and insufficient pouring of steel castings, the wall thickness of steel castings cannot be less than 8mm; use dry casting or hot casting, and increase the pouring temperature appropriately, generally1520~1600C, because the pouring temperature is high, the superheat of the molten steel is large, the liquid state can be maintained for a long time, and the fluidity can be improved. However, if the pouring temperature is too high, it will cause defects such as coarse grains, thermal cracks,pores, and sand sticking.Therefore,for general small, thin-walled,and complex-shaped precision castings, the pouring temperature is about the melting point temperature of steel +150C. The structure of the pouring system should be simple and the cross-section size should be larger than that of cast iron. The pouring temperature of large, thick-walled castings should be higher than that of cast iron. Its melting point is about 100℃ higher.
