J. Behringer et W. Syllwasschy, TENSION LEVELING OF ELECTRICAL SHEET USIN G A MECHANICAL TENSION BRIDLE AS A TENSION UNIT, Stahl und Eisen, 115(12), 1995, pp. 85
An ''Umlauf'' or mechanical plate-type chain tension bridle was instal
led as a tension unit in the exit of a tension levelling line. On this
line, annealed and temper-rolled semi-finished electrical sheet was t
ension-levelled with different elongations. The intention was to exami
ne whether the critical cold reduction which initiates the grain growt
h during the final anneal can be imparted by tension levelling alone o
r also by a combination of temper rolling and tension levelling, and h
ow this improves the magnetic properties. In addition, it was to be de
termined whether the correction of coilset (longbow) and crossbow is p
ossible. An ''Umlauf'' or plate-type chain tension bridle was integrat
ed in place of a tension roll assembly in a tension levelling line. Wi
th this arrangement it was possible to easily achieve elongations in t
he order of 9% for annealed strip, and total elongations in the order
of 9.4% for annealed and temper-rolled strip. Coilset (longbow) and cr
ossbow were corrected by means of the bending roll and correction roll
settings. A distribution of tension builds up between the tension lev
eller and the tension unit which is consistent with the fibre length d
ifferences remaining over the strip width after the levelling process.
Up to elongations of around 6%, continuous furnace annealed and tensi
on-levelled strip exhibits reduced core losses. If the annealed strip
is temper-rolled prior to the tension levelling, such losses are signi
ficantly lower, with polarisation values undiminished.