Pouring has a great influence on the quality of castings. The more complex the pattern is, the more important it is to determine a reasonable Pouring Scheme.
During pouring, the pressure in the mold cavity is formed due to the gasification of the pattern. The type and quantity of gasification decomposition products vary with the pouring temperature. In addition, it is vacuum pouring, so the filling process of molten metal is very complex. Because the displacement lost foam casting model is endothermic reaction, the pouring temperature of lost foam casting is higher than that of ordinary sand mold casting, generally 30-50 ℃.
It is very important to determine the pouring scheme of lost foam casting. Generally, the most suitable pouring scheme is obtained by repeated tests. For iron castings and steel castings, in order to eliminate decomposition products smoothly without pores and slag inclusions, the sprue cup must be filled during pouring, and the filling should be based on the principle of stability and speed.