Analysis of advantages and disadvantages of stainless steel precision casting process:
Friends in the casting 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. It is called investment casting or precision casting. Its melting point is relatively high, and the liquid steel is easy to oxidize, the fluidity of molten steel is poor and the shrinkage is large. In fact, from the practical point of view, the casting of stainless steel precision pipe is not only suitable for the casting of various types and alloys.
Next, Xiaobian will explain the advantages and disadvantages of stainless steel precision casting process for you: first, due to the poor fluidity of liquid steel, in order to prevent cold insulation and insufficient pouring of steel castings, the wall thickness of steel castings cannot be less than 8mm; The structure of the gating system shall be simple and the section size shall be larger than that of cast iron; Dry mold or hot mold shall be adopted; Properly increase the pouring temperature, generally 1520 ° ~ 1600 ℃, because the pouring temperature is high, the superheat of molten steel is large, the liquid holding time is long, and the fluidity can be improved.
However, too high pouring temperature will cause defects such as coarse grain, hot crack, porosity and sand sticking. Therefore, the pouring temperature of small, thin-walled and complex castings is about the melting point temperature of steel + 150 ℃; The pouring temperature of large and thick wall castings is about 100 ℃ higher than its melting point.
In order to prevent the occurrence of shrinkage cavities and cracks in stainless steel precision castings, we must take these measures to make its wall thickness uniform and avoid sharp corners and right angle structures. In addition, sawdust needs to be added in the mold for casting, coke needs to be added in the core, and finally hollow core and oil sand core need to be used to change the concession and air permeability of sand mold or core. As long as we deal with it according to what Xiaobian said, we can achieve the expected effect.
