Compostions and Applications of iron carbon steels

Low carbon steel

• 0.07 - 0.15%, very workable, soft

• Automobile body parts and wire products

Microstructure

• Pearlite + Proeutectoid ferrite

Mild carbon steel

• 0.15 - 0.30%, suitable for welding

• Most common type, structural plates and sections, stamping, forgings

Microstructure

• Pearlite + proeutectoid ferrite

Medium carbon steel

• 0.30 - 0.60%, hard yet still workable

• Forgings and automobile components including shafts, axels and gears

Microstructure

• Pearlite + proeutectoid ferritE

High carbon steel

• 0.60 - 1.25%, very hard, durable

• High strength springs and wires, cutting tools, punches and industrial knives

Microstructure

• Pearlite + proeutectoid ferrite

• Purely perlite

• Pearlite + proeutectoid cementite

Ultra high carbon steels

• 1.25 - 2.0%, extreme hardness

• Extreme wear resistance, requires tempering

• Non industrial Knives, punches and axels

Microstructure

• Pearlite + proeutectoid cementite