1. Since the shrinkage of stainless steel pipe castings greatly exceeds the shrinkage of cast iron, in order to prevent shrinkage and shrinkage defects of castings, most of the measures used in the casting process are risers, cold iron and subsidies to achieve continuous solidification.
2. In order to prevent the shrinkage, shrinkage, porosity and crack defects of the stainless steel tube, the wall thickness should be uniform, avoid sharp and right-angle structures, add wood chips to the molding sand, add coke to the core, and use hollow core and oil sandstone to improve the concession and breath-ability of sand or core.
3. Due to the poor fluidity of molten steel, in order to prevent cold separation and inadequate casting, the wall thickness of the casting should not be less than 8mm; dry casting or hot casting should properly increase the casting temperature, generally 1520 ~ 1600 ℃. Because the casting temperature is high, the degree of super-heat is high, the liquid retention time is long, and the fluidity can be improved. However, if the temperature is too high, it will cause defects such as coarse grains, hot cracks, pores and sand sticking.
Post time: Apr-08-2020