The casting methods mainly include sand mold gravity casting, lost foam casting, pressure casting, centrifugal casting, etc. the cast steel joint of the four branch pipes adopts sand mold gravity casting. The casting process is divided into five steps: melting, molding, casting, heat treatment and post-treatment.
In the molding process, if the casting is a casting with cavity, it is necessary to set sand core. The sand core is fixed at a specific position in the sand mold with a core support. After the casting is completed, the sand core is wrapped in the casting. Breaking the sand core forms the cavity in the casting. Sodium silicate sand, furan resin sand and quartz sand can be used for sand casting. Quartz sand is used for this casting. After the casting is completed, the pouring riser needs to be cut for further follow-up processes such as nondestructive testing. As shown in Figure 1 and Figure 2, the sand mold placement and riser cutting of cast steel joints are shown.