【Summary】First of all, for the blowhole defects in the heat resistant steel charging tray casting, its gas enters the heat resistant steel charging tray casting and then produces the blowhole during the gas process of the lost foam splitting decomposition. To some extent, there will be turbulent flow when filling. And in the case of top pouring or side pouring, parts of patterns will split after being surrounded by the metal liquid.
The gas produced on the heat resistant steel charging tray casting can't be discharged from the metal, to a great extent, which will produce the blowhole directly, and will be accompanied by the carbon black. In order to prevent this phenomenon, we should pay attention to improving the process which is to replace the layer by layer during the filling process
Moreover, if there is poor drying on the pattern or coating of the heat resistant steel charging tray casting, to a great extent, it will directly cause the blowhole.
As a result, it will produce a large amount of gas when pouring if the pattern has moisture or the coating has poor drying or the content of the blowing agent is high.
In this way, it will regurgitate. And it will be easier to produce the blowhole.
In the end, the drying coating of the heat resistant steel charging tray casting is not enough, which will lead to too much moisture content. And at the same time, it will be easier to form the invasive blowhole. For the defect of the heat resistant steel charging tray casting, the coating must keep dry.