# Mechanical Properties of Steel

Steel is quite a versatile alloy of iron that is used in everyday life. The mechanical properties of steel make it a raw material for different types of products, ranging from safety pins to structural support in buildings.

ScienceStruck Staff

Last Updated: Sep 14, 2018

Mechanical Properties

- Tensile strength
- Hardness
- Toughness
- Elasticity and Plasticity
- Brittleness
- Malleability
- Ductility

Tensile strength

Tensile strength is a property that refers to the amount of stretching a material can withstand. It is the maximum amount of tensile stress a particular material can stand before breaking. It is measured by dividing the cross section of the steel by stress exerted on the area.

Hardness

This property of steel determines the resistance of the alloy to deformation, penetration, scratching, machining, and abrasion. The common tests used for calculating the hardness of this alloy are Brinell, Vickers, and Rockwell.

**P/[pi (d/2) {D-√(D**

^{2}- d^{2})}],**where, P is the load, D is the diameter of the steel ball, d is the diameter of the indentation on the ball surface. Similarly, Vickers test calculates the hardness using the formula: 1.854P/L2, where, L is the diagonal length of the indentation and P is the load applied.**

Elasticity

The ability of an alloy to regain its normal shape after being subjected to an external force temporarily is called elasticity. It implies, solids with low elasticity either break or are deformed after the external force is applied.

*Tensile stress/Tensile strain*= (F/A)/(∆L/L

_{0}), where, F is the force applied, A is the cross-sectional area of steel subjected to force, ∆L is the change in the length of the steel object, and L

_{0}is the original length of steel object. The elasticity of steel (SAE 950) is 30 x 10

^{6}psi.

Ductility and Malleability

Ductility and malleability are mechanical properties that determine the utility and application of steel. Ductility determines the extent to which the alloy can be deformed plastically (rather stretched) without fracture.

Mechanical Properties of Stainless Steel

- Martensitic
- Ferritic-martensitic
- Ferritic
- Ferritic-austenitic
- Austenitic