The mechanical properties of cast iron castings is high, but its performance is worse than cast iron castings.Because stainless steel precision casting high melting temperature of liquid steel in molten steel easy oxidation, liquiditydifference, shrinkage, the shrinkage rate of 10 ~ 14%, line shrinkage is 1.8 to 2.5%. in order to prevent the steel castings produced misrun, cold isolation, shrinkage cavity and porosity, crack and sandand other defects, must takemeasures than the cast iron complex:
Because the stainless steel precision casting shrinkage significantly more than the cast iron, in order to prevent the casting shrinkage hole, shrinkage defects in the casting process, most of the riser and chill andsubsidies and other measures to achieve the progressive solidification.
Due to the mobility of liquid steel, steel castings produced in order to prevent the cold shut and misrun, wall thicknessnot less than 8mm structure of steel castings; pouring system precision castings to simple, andsection size than cast iron; dry cast or hot mould;
Proper increase of pouring temperature, generally 1520 ° to 1600 ℃, because of high temperature casting,molten steel superheat, keep a long time, liquidity can be improved. But the pouring temperature is too high,will cause thecoarse grain, hot cracking, porosity and sand and so on. So the general small, thin wall andcomplex shape casting,the casting temperature is about steel melting temperature +150 ℃;
A large, thick wall castings pouring temperature higher than the melting point of 100 degrees Celsius.
