During a metal rolling operation, t

During a metal rolling operation, the geometric shape of the work is changed but its volume remains essentially the same. The roll zone is the area over which the rolls act on the material, it is here that plastic deformation of the work occurs. An important factor in metal rolling is that due to the conservation of the volume of the material with the reduction in thickness, the metal exiting the roll zone will be moving faster than the metal entering the roll zone. The rolls themselves rotate at a constant speed, hence at some point in the roll zone the surface velocity of the rolls and that of the material are exactly the same. This is termed the no slip point. Before this point the rolls are moving faster than the material, after this point the material is moving faster than the rolls.