At its Bochum plant for NO grades, thyssenkrupp Steel Europe uses a laser sensor system from nokra to measure the edge waviness of non-grain oriented strip. This optical inline measuring process has replaced the previous practice of manual offline edge-wave measurements. The new system can even handle moving strips, thus enabling the measurement of edge waviness along the entire coil length.
At its NO plant in Bochum, TKSE produces non-grain oriented electrical strip in thicknesses from 0.2 to 1.0 mm. The strip is heat-treated in three continuous annealing furnaces to achieve the physical and magnetic properties required.
According to standard EN 10251, wavy edges have to be measured and documented after the final heat treatment. During the measurements, the strip has to be tension-free.
The offline measurements at the No. 6 annealing furnace used to involve a great manual effort: Specimens had to be cut out at the strip head and tail ends and placed on a flat table. There, the wave lengths were manually measured and the wave heights determined using a wedge, according to the procedure laid out in the applicable standard.