J. Epp, Eng., Andritz Sundwig GmbH, Hemer ; juergen.epp@andritz.com

It is not possible to avoid forming of flatness defects and high internal residual stresses in current manufacturing products of stainless and high strength steels. In this connection, ThyssenKrupp Steel Europe uses precision units for straightening of heavy plates that help to meet new requirements regarding flatness and internal stresses. The paper examines production process st ThyssenKrupp works in Duisburg-Hüttenheim and describes the concept and construction features of straightening machine developed by Andritz Sundwig GmbH. It is devoted for processing rolled material with thickness 3-60 mm, width 700-3,800 mm and length 4.0-16.5 m; productivity makes 144,000 tpy. It is possible to use different number of straightening rolls as well as rolls with different diameters, using standard scheme - 13/17/21 or 9/13/17 for three-cassette modification. It is concluded that use of intermediate rolls increases service life of all rolls substantially due to better distribution of strength between work rolls and backup rolls. It is important that in spite of high processing temperature (up to 700 ºC) no intensive water cooling is required. Straightening process is completely automatized, straightening is followed by the unit for measuring sheet flatness for 100% control of all processed products.