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The Key Differences Between Cast Iron and Cast Steel

The quickest methods to distinguish between cast iron and cast steel involve visual inspection, sound testing, and simple mechanical checks. Key differences are outlined below:
1. Surface Brightness: Cast steel typically has a brighter, smoother, and more refined surface. Cast iron, especially gray iron, appears duller and darker gray. Ductile iron may have a slightly brighter finish than gray iron but is still less shiny than cast steel.
2. Grain Visibility: Cast steel has a fine, dense grain structure that is generally not visible to the naked eye. In contrast, cast iron (both gray and ductile) exhibits a coarse grain structure. Gray iron has particularly large and clearly visible grains.
3. Sound Test: When struck, cast steel produces a clear, ringing sound similar to steel plate. Cast iron, on the other hand, emits a duller, shorter sound. Gray iron has a particularly flat, low-pitched tone.
4. Gas Cutting Test: Cast steel can be easily cut using gas cutting techniques due to its higher melting point and composition. Ductile iron is difficult to gas cut cleanly, while gray iron typically does not allow gas cutting at all.

5. Toughness Test: Cast steel shows good toughness and can be bent or deformed without fracturing. Ductile iron has some toughness but is more brittle than cast steel. Gray iron is highly brittle and will break easily under impact or bending force.