It is in the cold continuous annealing and pickling line where the treatment of the strip is performed, providing the metallurgical structure of the stainless steel.
At temperatures between 800 °C and 200 °C the recrystallization takes place in the furnace before the strip is cooled from top and bottom by means of air blowing, conventional water spray cooling and air mist spray cooling. Often it is a combination of all three methods. Varying steel grades and line speeds require specific cooling rates to avoid carbide precipitation at grain boundaries. The special Lechler air mist cooling header design is providing exactly that. The 1 : 10 water control ratio (turn-down ratio) allows a precise setting with perfect spray patterns from min. to max. line speeds. The large spray overlaps ensure a uniform cooling over the entire strip width for an optimal thermal homogeneity across the strip.