Journals →  Chernye Metally →  2020 →  #6 →  Back

Rolling and Other Metal Forming Processes
ArticleName Evaluation of thick sheet flatness in automatic mode
ArticleAuthor M. Laugwitz, J. Lomar, G. Hirt, S. Soiren, M. Jochum

Institute of Plastic Deformation of the Rhein-Westfalen Technical University (Aachen, Germany):

M. Laugwitz, Researcher, e-mail:
J. Lohmar, Dr. Eng., Prof.
G. Hirt, Dr. Eng.


Saarstahl AG (Völklingen, Germany):
S. Soiren, Dr. Eng.

AG der Dillinger Hüttenwerke (Dillingen (Saar), Germany):
M. Jochum, Dr. Eng.


Flatness is the most important quality characteristic in the production of high quality thick sheet. Its necessary level is achieved during the flattening process. To optimize the process and accounting for the formation of flatness defects during flattening, it is necessary to describe them by means of characteristic indicators. Since all technological parameters are archived in the database, defects by classes can be compared with production conditions and, as a result, the flattening process can be optimized. In order to obtain a sheet with the flatness required by the customer after the hot rolling or subsequent cooling stage it is usually subjected to a flattening process. During this processing, the sheet undergoes alternating bending, and the material undergoes elastic-plastic deformation. This enables to change the initial level of internal stresses and as a result get a flat sheet. In case of a thick sheet, the flattening process is carried out in a reverse mode and, depending on the severity level of the defect, is implemented in several stages. The decision on the intensity and number of flattening passes is made by experienced production personnel, as a rule, based on the corresponding geometric and physical characteristics of the sheet material, as well as estimates of the initial flatness level.

keywords Flatness, quality, control, thick sheet, defect

1. Loges F. Entwicklung neuer Strategien zur Messung und Regelung der Bandplanheit beim Flachwalzen, Universität Kassel. 2009. (Diss.).
2. Henrich L. Theoretische und experimentelle Untersuchungen zum Richtwalzen von Blechen, Universität Siegen. 1994. (Diss.).
3. DIN EN 10029:2010: Warmgewalztes Stahlblech von 3 mm Dicke an — Grenzabmaße und Formtoleranzen, deutsche Fassung. 2010.
4. Gong D., Xu J. Research on single-side long edge of hot rolled strip caused by asymmetrical stiff ness of mill stand, SciRP, 2011.
5. Tsuzuki S., Kira Y., Misumi K. Flatness control system of cold rolling process with pneumatic bearing type shape roll. IHI Eng. Rev. 2009. Vol. 42. Nr. 1. S. 54–60.
6. Laugwitz M., Seuren S., Jochum M., Lohmar J., Hirt G. K. P. Flatness characterisation of hot plates for plate levelling. Proc. European Steel Technology and Application Days (ESTAD) 2017. 26–29 Juni 2017. Wien, Österreich.
7. Mücke G., Karhausen K. Formabweichungen in Bän-dem: Einteilung, Entstehung : Messung und Beseitigung sowie quantitative Bewertungsmethoden. Stahl u. eisen. 2002. Vol. 122. Nr. 2. S. 33–39.

Language of full-text russian
Full content Buy