2. Continuous annealing lines

2.1 Continuous annealing lines for tinplate

Continuous annealing lines were first developed for the annealing of 0.25 to 0.40 mm thick strips for tinplate. In fact, it is for these strips that coil annealing is the most difficult, due to the risk of sticking and, consequently, of breakage or tearing when the strip is uncoiled after annealing. The width of tinplate strip is between 0.75 and 1.25 m and, consequently, continuous annealing lines for strip intended for the manufacture of tinplate or chromium-plated iron are limited in width to a maximum of 1.25 m. For the manufacture of can bodies, the stiffness of continuously annealed steels facilitates the production of stiff grades. Low-temperature recrystallization of thin strips with a reduction rate generally > 80% is also advantageous....