Mechanical properties and chemical composition

The mechanical properties of steel are primarily determined by the chemical composition of the steel. As steel has a number of useful mechanical properties in relation to other metals and their alloys, steel has a very wide range of applications.

Mechanical properties

The most important mechanical properties of steel are:

• Strength: the resistance that steel offers to fracture tension.
• Ductility versus brittleness. Ductility is the extent of deformation that steel can withstand before fracturing. Brittleness is the extent to which the steel fractures when force is exerted on it without stretching it.
• Hardness: the resistance that steel offers to fracture tension.

• These properties of steel are determined by means of the tension test, the notched-bar impact test and measurement of hardness.

  Tension test

  In the tension test tensile force is applied to the steel and the behaviour of the steel under gradually increasing tensile strain is measured. When the limit of elasticity is reached, the steel begins to deform permanently.