Further development of the flange-tip straightening process
The previous ECSC project, 7215-EA/803, demonstrated the successful flange-tip straightening (FTS) of large beams. The work in that project focused on applying the technique in principle to mill - in this case, Teesside Beam Mill (TBM). Difficulties arise due to the variation of flange heights, both side to side and along the length of the section. To some extent this can be overcome by 'overstraightening' the section; that is using more penetration than is necessary to straighten the section, therefore straightening the flanges sufficiently. An investigation into flange height variation has been performed with the aim of specifying the applicability of the technique to a mill with a certain flange height variation during rolling. Another significant and perhaps more important difficulty with the technique is that horizontal out of straightness, or camber, cannot be rectified as easily with FTS as with conventional straightening. Unlike conventional straightening, the section is not 'squared up' over the tightly built up rolls on the RSM to reduce camber. In addition, the use of axial penetrations during production flange-tip straightening cannot be recommended due to the interaction with vertical penetrations. During this project, work has focused on the use of the exit vertical rolls (reverse bending unit at BFI) operating with either a full FTS set up or with a hybrid FTS/conventional roll set up. The hybrid technique is discussed in more detail later in the report, but essentially uses FTS rolls early in the machine, where the penetrations are higher, and conventional rolls later in the machine, where the penetrations are expected to be lower. Hybrid straightening in conjunction with the use of exit vertical roll adjustments is the recommended method to reduce camber.
Bibliographic Reference: EUR 21914 EN (2005), 108pp. Euro: 25
Availability: Katalogue Number: KI-NA-21914-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.europa.eu
ISBN: ISBN: 92-79-00125-6
Record Number: 200618558 / Last updated on: 2006-04-28
Original language: en
Available languages: en