Chemicals

Property

Effects on the Rebar’s

Carbone (C)

Hardness, strength, Weldability and brittleness

Higher carbon contributes to the tensile strength of steel, that is, higher load bearing capacity and vice versa. Lower carbon content less than 0.1% will reduce the strength. Higher carbon content of 0.3% and above makes the steel bar unweldable and brittle.

Manganese (Mn)

Strength and yield strength

Higher manganese content in steel increases the tensile strength and also the carbon equivalent property.

Sulphur (S)

It is an impurity in steel which increases its brittleness.

Presence of sulphur should be limited. Presence of higher sulphur makes the bar brittle during twisting, as higher sulphur content brings the hot shot problem during rolling.

Phosphorus (P)

It is an impurity which

Increases strength brittleness

Higher phosphorus content contributes to the increase in strength and corrosion resistance properties but brings brittleness due to the formation of low euctoid phosphicles in the grain boundary. Also lowers the impact and value at subzero temperature level (transition temperature).

Copper (Cu)

Strength and corrosion

resistance

Being a pearlite stabiliser, it increases the strength and resistance corrosion property.

Chromium (Cr)

Weldability and corrosion resistance

Present as an impurity from the scrap and influences carbon equivalent; weldability and increases corrosion resistance property.

Carbon Equivalent

(CE or Ceq)

Hardness, tensile strength and weldability

This property is required to set the cooling parameters in TMT (thermomechanically treated) process and a slight variation in carbon equivalent may alter the physical properties.