20-high cold rolling mill

The 20-high cold rolling mill is a MonoBlock mill, type MB 22B-54“, and processes hot strip thicknesses of up to 6.2 millimeters. The compact and robust plant comes with high mill stand rigidity. Featuring a maximum rolling speed of 800 meters per minute and a maximum rolling force of 8,000 kilonewtons, it can achieve thickness reductions of up to 90 percent. Auxiliary and ancillary equipment is also included in the scope of supplies. A regenerative SUPAFINE® filter system makes sure the rolling oil is ecofriendly purified and cooled. Ecological plant operation is further supported by a fume exhaust system meeting most stringent environmental provisions of the local authorities. To reduce non-productive times, an uncoiling station, including flattener and crop shear, is integrated in addition to two reversing reels.

The hydraulic valve stands arranged on the mill stand platform are easily accessible and greatly simplify maintenance work.
The mill stand is equipped with hydraulic roll gap control and crown adjustment for
backup shafts B/C and F/G as well as with inner intermediate roll shifting.
A four-high skin-pass mill stand is integrated in the exit section of the facilities to improve surface and flatness as well as the metallurgical material properties. Strip flatness is then perfected by a downstream tension leveler. Thereafter, both strip edges may be straightened by a side trimmer.

Bright-annealing line

In the bright-annealing line the strip first runs through the cleaning section. This step is followed by recrystallization annealing in an oxygen-free inert gas atmosphere with high hydrogen content, in an all-electric vertical furnace from Drever International, a company of SMS group. The annealing process is performed at a temperature of up to 1,250 degrees Celsius in an inert gas atmosphere (up to 90 percent hydrogen) under overpressure to thus generate a perfect glossy surface. The exit section of the facility is equipped with a four-high skin-pass stand and a tension leveler for strip post-treatment. A side trimmer serves for strip edge straightening and cuts the strip to the desired width.

In a two-stage cleaning section, the cold rolled strip is efficiently freed from rolling oil and other dirt particles.
In the entry and exit sections, maximum strip speed reaches 75 meters per minute, whereas in the process section the material goes through at maximum 50 meters per minute.

The technological highlight of the bright-annealing line is the all-electric vertical furnace from Drever International. Due to its high efficiency, the energy consumption of about 220 kilowatt hours per ton is 60 percent lower than that of a conventional line concept with muffle furnace.