Iron Casting Process
Pattern Making
Design and Creation: Patterns are typically made from wood, plastic, or metal, and are used to form the shape of the mold cavity.
Core Boxes: For creating cores that will form internal cavities in the casting.
Mold Making
Sand Molding: Most iron castings are made using green sand or resin-bonded sand molds.
Green Sand Molding: Mixing sand with clay and water to create a mold.
Resin-Bonded Sand Molding: Mixing sand with a resin binder for more complex or higher precision molds.
Mold Assembly: Assembling the cope and drag and placing cores if needed.
Melting
Cupola Furnace: Commonly used for melting cast iron. It’s a vertical cylindrical furnace.
Induction Furnace: An electric furnace that provides precise temperature control and is more efficient for melting.
Pouring
Pouring the Molten Iron: Pouring the molten iron into the mold through a gating system designed to control the flow and minimise turbulence.
Solidification and Cooling
Controlled Cooling: Allowing the iron to cool and solidify in the mold. Proper design of risers helps compensate for shrinkage.
Shakeout and Cleaning
Shakeout: Removing the sand mold and separating the casting.
Cleaning: Removing any residual sand, scale, or oxides from the casting surface.
Heat Treatment (if required)
Annealing: Heating and slow cooling to soften the iron and improve machinability.
Stress Relieving: Heating to a lower temperature to relieve internal stresses without changing the microstructure significantly.
Finishing and Inspection
Fettling: Removing excess material, gates, risers, and flash from the casting.
Inspection: Using visual inspection, dimensional checks, and non-destructive testing (NDT) methods.
