several major events need to pay attention when produce large iron castings

several major events need to pay attention when produce large iron castings
Keywords: cast iron castings
A large cast iron character include : thick wall, pouring molten iron and more, heat capacity, freezing for a long time, easy to produce a variety of defects, such as sticky sand, shrinkage deformation, large castings defects appear sticky sand. Therefore, the production process has the following issues that need attention.A cold iron. In order to ensure uniform solidification of the casting, the surface does not need to set up a cold iron corrosion coating on the surface to be cold iron, cold iron castings and more preferably with hot air before pouring hot, cold iron sand between certain cold iron thickness should be casting wall thickness of 0.5 to 1.0 times.2 cores. Cores have sufficient strength, the airway smooth.3 pit. Casting pit is the production of large cast iron is a major feature, you can reduce the sand box, simplifying the sand box structure to reduce lifting weight, pit casting sprue plane height can be reduced to prevent splashing of molten iron, ease of operation and safety, large iron castings solidification cooling time is long, the pit can insulation, may be appropriate to eliminate casting stress.4 casting method. For large iron castings, it is often used more than runner runner dispersed layered, semi-closed or not closed the bottom gating system, but they use fast pouring, flat runner.5 riser. Repair of large castings are to be considered, and is a riser or hot riser placement must be reasonable.