A New Sensor Concept for Roll Gap Measurements in Cold Flat Rolling

摘要

The new ROLLSURF concept of measuring the accumulated normal forces and friction forces with a transducer much longer than the contact zone determining the normal pressure and friction stresses by differentiating the forces is here proven to be valid. The proposed method for calibrating the transducer and the mathematical model describing the transition of the strain gauge signals into forces has also been verified. Reliable and reproducible measurements have been carried out. The Forward Slip calculations of the coefficient of friction mu at Ruukki Production Hameenlinna cold mill in Finland and at one of Sandvik MT cold mills in Sandviken, Sweden, have been compared to the ROLLSURF transducer measurements of the friction coefficient mu in the MEFOS pilot mill in Lulea, Sweden. The result was that the ROLLSURF measurements was in good agreement with the cold mill calculations and in all three cases did the coefficient of friction mu increase with increasing reduction, as expected, when cold rolling different steel grades.