Pattern Making
Pattern Design: Similar to iron casting, but often requires more robust materials due to the higher temperatures of molten steel.
Mold Making
Sand Moulding: Green sand or chemically bonded sand is used, but with additional measures to handle the higher temperatures and reactivity of steel.
Investment Casting: For precision steel parts, creating a wax pattern that is coated with ceramic material to form a mold.
Melting
Electric Arc Furnace (EAF): Common for steel melting, using electrical energy to melt scrap steel and other materials.
Induction Furnace: Used for smaller batches and specialty steels.
Pouring
Pouring the Molten Steel: Carefully pouring the molten steel into the pre-heated mould to prevent rapid cooling and defects.
Solidification and Cooling
Controlled Solidification: Ensuring uniform cooling to prevent internal stresses and defects. Steel typically requires more attention to cooling rates compared to iron.
Shakeout and Cleaning
Shakeout: Breaking the mould to remove the solidified casting.
Cleaning: Often involves more rigorous methods such as shot blasting to remove the tougher scale and residues from steel castings.
Heat Treatment
Normalising: Heating to a temperature above the critical range and air cooling to refine the grain structure.
Quenching and Tempering: Heating and rapid cooling followed by reheating to a lower temperature to achieve desired mechanical properties.
Finishing and Inspection
Machining: Steel castings often require more extensive machining due to tighter tolerances and complex shapes.
Inspection: Comprehensive inspection using visual, dimensional, and NDT methods such as ultrasonic testing, magnetic particle testing, and radiography.
Chemical Analysis: Ensuring the chemical composition meets specifications using spectroscopy or other methods
Mechanical Testing: Testing mechanical properties such as tensile strength, hardness, and impact resistance.
Non-Destructive Testing (NDT): Techniques like radiographic testing, ultrasonic testing, and dye penetrant testing to detect internal and surface defects.
