Preliminary straightening of thick steel sheet in a seven-roller machine

Abstract

A mathematical model is proposed for determining the forces and torques in the preliminary cold straightening of thick steel sheet in a seven-roller machine. On that basis, the bearing reaction of the working rollers, the residual stress in the wall of the steel sheet, the proportion of plastic strain over the sheet thickness, and the relative strain of longitudinal surface fibers of the sheet in straightening may be determined as a function of the working-roller radius, the spacing between rollers of the straightening machine, the reduction of the sheet by the upper rollers, and the sheet thickness, as well as the Young’s modulus, yield point, and strengthening modulus of the sheet. The results may be used at manufacturing and metallurgical plants.