CHANGING METHOD FOR ROLLING REDUCTION IN EDGING WORK FOR SLAB

摘要

PURPOSE:To control the breadth reduction in the next rolling pass, and to imporve the yield, by obtaining the change of the rolling load and the breadth transformation of the slab in the present rolling pass. CONSTITUTION:The change DELTAP of the rolling load in the present rolling pass is stored as the function of the time, DELTAP=f(t). Then, the total rolling time of this stored rolling pass is taken as t0 and the total rolling time of the next rolling pass to be determined from the elongation of the slab is taken as ton, and the ratio of the rolling times, ton/t0=alpha is operated. The time T0 of producing the control output for the rolling reduction in the next pass is determined. The change DELTAP of the rolling load in the present pass is made a function of the time T. Meantime, the change DELTAP of the rolling load and the breadth transformation DELTAW of the slab have a relationship DELTAW=betaDELTAP, in which beta is a factor. On the other hand, the edging rate DELTAE and the breadth transformation DELTAW have a relationship DELTAW=etaDELTAE, in which eta is the breath adjustment efficiency; accordingly, the edging rate DELTAE is given by DELTAE=1/eta.beta.f(T), so that the control output DELTAE is produced for every corresponding time T for performing the edging pass.