Flatness Defects in Cold-Rolled Strip and Testing of a Flatness Measuring Device.

The nonadjustable flatness defects encountered in cold-rolled strip are due to differences in the length of the strip. In most cases, these defects comprise a number of individual defects. The required measuring accuracy can be ensured only when the length differences in the strip are determined from the distribution of the tensile stress. The developed flatness measuring device operates on this principle. It is designed like a deflection roll and detects the tension-proportional local deflection force for the deflection of the strip around the roll. This flatness measuring device was tested on a three-stand cold rolling mill for dry temper-rolling of extra-light-gage sheet and rolling of double-reduced stock. During these tests, the device worked troublefree.