Composition of the steel and its percentage

Identify the composition of steel and explain how the percentage composition of steel can determine its properties

  • There are an unlimited number of steel compositions, with each one having different properties.
  • The three most commonly used steels are mild steel, structural steel and stainless steel:

Steel:   Composition:Properties:Uses:

Mild    
  • <0.2% C    
  • Soft and malleable.
  • Corrodes fairly rapidly. 
  • Pipes.
  • Nuts and bolts.
  • Roofing.
  • Shipbuilding.

Structural
  • 0.3-0.6% C
  • Hard and malleable.
  • High tensile strength.
  • Corrodes fairly rapidly.
  • Beams and Girders.
  • Railways.
  • Reinforcing for buildings.

Stainless

  • 10-20% Cr
  • 5-10% Ni
  • Hard.
  • Takes a high polish.
  • Very resistant to corrosion.
  • Food processing machinery.
  • Kitchen sinks and appliances.
  • Cutlery.
  • Surgical instruments.
  • Razor blades.