Stainless steel casting is made by cast steel parts. In stainless steel castings, its mechanical properties is very high, but also its manufacturing process is very complex in stainless steel casting with a high melting point and low liquidity, so the stainless steel sand casting in the production is more complex.
To overcome the method of stainless steel castings are the following:
In stainless steel sand casting,due to the cast steel shrinkage significantly is more than cast iron, stainless steel casting in order to prevent the emergence of the shrinkage defects,it adopt mostly the riser,cold iron and subsidies,etc in the casting process and achieve sequential solidification. In addition, prevent the shrinkage hole, shrinkage porosity and cracks from stainless steel sand casting,it should make wall thickness uniformity and avoid sharp corners and rectangular structure.Molding sand with sawdust in the casting mold, coke in the molding core and improve the concession and permeability of sand mold or cores.
Due to the poor fluidity of molten steel, prevent the cold shut and misrun of stainless steel casting, wall thickness of stainless steel sand casting is not less than 8ram; the structure of the casting system simple, and section size ratio is bigger than cast iron;increasing casting temperature, usually is 1520 C ~ 1600 C, because high pouring temperature and molten steel superheat, keep liquid for long time , liquidity can be improved. But too high pouring temperature will lead to coarse grain, hot cracking, blowhole and sand sticking. As a result, the pouring temperature of stainless steel castings with small size and thin wall and complex shape is about the melting point of steel temperature is +150℃.The pouring temperature of large and thick wall stainless steel sand castings is about 100 degrees higher than that of melting point.
Because high melting point of stainless steel sand casting,so the corresponding pouring temperature is very high.And also due to casting material interaction at the same time,it is easy to be sticky sand defection, so usually adopts artificial quartz sand casting method.