Cast Iron
WHAT IS CAST IRON?
Cast iron is produced by smelting iron-carbon alloys with a carbon content greater than 2 percent, which is then poured into a mold. Throughout history its usefulness came from its relatively low melting temperature.
Cast iron retains its strength under compression but not when under tension. It is comparatively brittle and is not suitable for applications that require sharp edges or flexibility.
Cast iron and wrought iron are somewhat similar but have different chemical structures and physical properties. Unlike wrought iron, cast iron is not worked with hammers and tools.
Cast iron contains 2 percent to 4 percent carbon and other alloys and 1 percent to 3 percent silicon. The silicon improves casting performance. Cast iron may also have small amounts of manganese and impurities like sulfur and phosphorous.
Cast iron’s relatively low melting point, excellent machinability, wear resistance, good fluidity, and resistance to deformation make it suitable for a wide range of applications.
CAST IRON SPECIFICATIONS
Steel and cast iron both contain traces of carbon and appear similar, yet there are significant differences between the two metals. Steel contains less than 2 percent carbon and solidifies in a single microcrystalline structure. Cast iron, however, has a higher carbon content and solidifies as a heterogeneous alloy that has more than one microcrystalline structure in the material.
Cast iron gets its excellent castability from its combination of high carbon content and silicon. Different heat treatment and processing techniques produces various types of cast iron. These include:
- White iron
- Gray iron
- Ductile iron
- Malleable iron
- Compacted graphite iron
The carbon impurities in white cast iron allow cracks to pass straight through. The graphite flakes in grey cast iron serve to deflect passing cracks and create new cracks when the material breaks. Ductile cast iron contains spherical graphite nodules that prevent cracks from progressing further.
Denver Rubber Company can design and manufacture the cast iron products you need. Contact us today.
