Analysis of the advantages and disadvantages of stainless steel precision casting processing technology:
Friends in the foundry industry know that the mechanical properties of stainless steel precision casting are higher than that of cast iron, but its casting performance is worse than that of cast iron, which is called investment precision casting or precision casting. Its melting point is relatively high, and the molten steel is easily oxidized, the fluidity of molten steel is poor, and the shrinkage is large. In fact, from a practical point of view, stainless steel precision tube casting is not only suitable for casting of various types and alloys.
Then the editor will explain to you the advantages and disadvantages of the stainless steel precision casting process: First of all, due to the poor fluidity of the molten steel, in order to prevent the cold insulation and insufficient pouring of the silicone casting, the wall thickness of the steel castings is It cannot be less than 8 mm; the structure of the pouring system is simple, and the cross-sectional size is larger than that of cast iron; dry casting or hot casting is used; the pouring temperature is appropriately increased, generally 1520 ° ~ 1600 ° C, because the pouring temperature is high, the molten steel The degree of superheat is large, the time of keeping the liquid state is long, and the fluidity can be improved.
However, if the pouring temperature is too high, it will cause defects such as coarse grains, thermal cracking, pores and sticky sand. Therefore, for small, thin-walled and complex-shaped castings, the pouring temperature is about the melting point temperature of steel + 150 °C; the pouring temperature of large and thick-walled castings is about 100 °C higher than the melting point.
In order to prevent the occurrence of shrinkage holes and cracks in stainless steel precision castings, we must take these measures to make the wall thickness uniform, and avoid sharp and right-angle structures. In addition, sawdust should be added to the mold for casting. , add coke in the core, and finally need to use a hollow core and an oil sand core to change the concession and permeability of the sand or core. As long as you follow what I’ve said, you’ll be able to achieve the desired effect.