Control of Quarter Buckle on Sendzimir 20-High Mills

THE problem of control of strip flatness in cold rolling has challenged the industry for a long time. The problem can be separated into two parts: measurement of flatness; and adjustment of roll gap profile to correct any deviation from the target detected by the measuring device. The flatness measurement problem has largely been solved, and several flatness measuring devices (shapemeters) are now available. These devices all have their limitations, eg, high cost, some are suitable for low tensions only, and frequent discrepancies may be found between their indicated flatness values and actual flatness (as measured subsequently on the strip). However, in general, for a given application, it is possible to obtain a shapemeter that will perform satisfactorily