Influence of process variables on development of camber during hot rollingof strip steel

Experimental design techniques have been used to study the effects of varia tions in horizontal scale breaker process parameters in relation to camber generation during the early reduction stages in a hot strip mill, A fractio nal factorial experiment was designed and performed to identify which proce ss variables are most influential to camber generation. The parameters whic h emerge from this analysis as being significant are: slab wedge, temperatu re differentials across the strip width, the deviation of the slab from the mill centreline, and mill tilt. A full factorial experiment was then desig ned and performed to further investigate these significant process paramete rs to determine where to set influential and control table variables so tha t camber is minimised. The results show that none of the process parameters is significant to camber generation when acting alone; however, they are a ll significant when combined with one or two other process parameters. This study has enabled a predictive equation to be developed which is able to p redict camber to within +/-4 mm, This equation may be used in conjunction w ith mill tilting strategies to reduce camber in the early reduction stages of a hot strip mill.