Process characteristics of precision castings
In the process of casting products, many customers need precision casting to make the products look more beautiful and beautiful, so today I will introduce the characteristics of the precision casting process.
The mechanical properties of precision castings are relatively high in the process of use, mainly because the melting point of their products is relatively high, the molten steel casted by precision castings is easy to oxidize, and the fluidity of the molten steel is poor and shrinks during operation. The rate is 10 to 14%.
In order to effectively prevent defects such as insufficient pouring, shrinkage cavity, shrinkage porosity, cold barrier, cracks and sand sticking in the casting of precision castings, it is necessary to adopt more complicated process measures than cast iron during use.
The shrinkage of precision castings during use greatly exceeds that of cast iron. In order to effectively prevent shrinkage and shrinkage defects in its castings during use, risers, chilled iron and subsidy measures are mostly used in the casting process. You can achieve sequential solidification.
Due to the relatively poor fluidity of molten steel in the casting of precision castings, in order to effectively prevent the cold barrier and insufficient pouring of the cast steel during use, the thickness of the cast steel should not be less than 8mm, and the structure of the pouring system should be simple. And the size of the section is larger than that of cast iron.
Because of the high pouring temperature of precision castings and the high degree of overheating of the molten steel, it needs to remain liquid for a long time during use. Its fluidity can be improved during use, but if the pouring temperature is too high, it will Directly cause defects such as coarse grains and thermal cracking.
Precision castings are generally small, thin-walled and complex-shaped castings. The pouring temperature is about 150 degrees, the melting temperature of steel. The pouring temperature of large thick-walled castings is about 100 degrees higher than the melting point.