The effects of rolling method changes on productivity in thick plate rolling process

We present a draft schedule scheme to estimate the productivity in thick plate rolling process. Dependency of design force, design torque and maximum bite angle of a rolling mill on the reduction ratio models were fully considered in the draft schedule scheme. Roll force and torque equations used in the reduction ratio models were verified by comparing the measurements with the predictions. Using the draft schedule scheme, we examined the influence of rolling method changes on the productivity (i) material position after the broadside passes, (ii) material position after the longitudinal passes and (iii) the number of turn, i.e., number of times that slab (material) is rotated by 90 degree, before the broadside and/or longitudinal passes begin. Results reveal that the number of turn gives the major influence on productivity. Rolling time can be minimized if material positions after the broadside and longitudinal passes are not fixed in advance.