The pouring and riser system includes two parts: steel casting system and riser system. The steel casting system is the channel to guide the liquid metal into the mold cavity in the sand mold. As shown in Figure 1, the general steel casting system is composed of sprue, transverse sprue, internal sprue, etc.
The gating system can be divided into middle injection, bottom injection and layered injection according to the injection position of the inner sprue on the steel casting. According to the drawings of the steel casting plant, the pouring system adopts the injection mode of intermediate injection.
The riser is a man-made structure for storing liquid metal in the mold, which is used to compensate for the possible shrinkage during the formation of steel casting, prevent shrinkage cavity and porosity of cast steel casting, and also play the role of exhaust, slag collection and guiding mold filling. The riser is generally set above the hot joint of steel casting, and shall be set at the highest and thickest part of steel casting as far as possible. Try to use one riser to feed several hot joints at the same time. For the hot joints at the lower part or those far away from the riser on the same horizontal plane, cold iron can be set to ensure sequential solidification and smooth feeding channel.
Risers are divided into exposed risers and concealed risers. According to the shape, they can be divided into standard cylindrical risers and standard waist risers. According to the process drawings of the steel casting plant, the size of the concealed riser that can be used for the riser is shown in Figure 2, which is divided into circular riser and waist riser. The circular riser is used in the actual cast steel casting. The section diameter of sprue is d = 80mm, the diameter of cross sprue D1 = 60mm and the diameter of inner sprue D2 = 30mm.