This is a heat treatment that restores the steel’s plasticity lost during the cold-rolling process. Annealing is the heating of steel to above the recrystallization point. The steel is heated in a reducing atmosphere (a mix of nitrogen and hydrogen) to avoid oxidation.
There are two annealing techniques :
• batch annealing.
• and continuous annealing. In the latter, tight control of the speed of the strip during the heating and cooling phases ensures complete regeneration of the steel grain.