ABSTRACT
Width variation plays an important role in determining product width tolerance. It is dif cult to predict and to control width variation in a portion of strip length in hot-rolling processes. As noted, these variations include width spreading or necking at strip heads and tails, as well as midwraps in an unstable rolling state. Most hot band users specify minimum widths in the orders. Coil producers provide extra widths to meet the speci cations for compensation of potential width necking, which does not only cause the loss of process yield, but also create a series of problems to the downstream processes, such as side trimming and spiral welding, etc.
