Some Benefits and Advantages of Cast Irons in Engineering Applications
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- Available in a wide range of mechanical/physical properties, i.e. tensile strength from 20 KSI to over 200 KSI, hardness from 120 to about 300 Brinell in standard grades and up to about 600 Brinell in special abrasion resistant grades
- Good strength to weight ratio
- Typically lower cost than competing materials and relatively low cost per unit of strength than other materials
- Lower density and higher thermal conductivity than steels at comparable tensile strength levels
- Excellent machinability, allowing for high speeds and feeds and
reduced (minimal) energy due to the presence of free graphite - Many iron castings can be used without heat treatment (as-cast) but, when needed, can be heat treated to enhance overall properties or localized properties such as surface hardness
- Excellent damping capacity, especially in Gray Irons
- Chemical analysis can be modified to provide improved special properties such as corrosion resistance, oxidation resistance, wear or abrasion resistance, etc.
- Rapid transition from design to finished product
- Capability of producing highly complex geometries and section sizes in a wide range of sizes, from ounces to over 100 tons
- Flexibility in design and ability to optimize appearance for sales appeal
- Possibility of casting intricate shapes as well as very thin to very thick section sizes
- Capability of redesigning and combining two or more components from other materials into a single casting, thus reducing assembly cost and time
- Capability of casting with inserts of other materials
- Variety of casting processes for low, medium or high production
- Reduced tendency toward residual stresses and warpage than some competitive materials
- A family of materials capable of meeting a wide variety of engineering and manufacturing requirements (the family includes Gray Iron, Ductile Iron, Compacted Graphite Iron, Malleable Iron, and White Iron)
(Above items adapted from a rough draft for AFS 5-M Committee by W. F. Shaw, ICRI)