The aluminium and stainless steel industries need a better understanding
of strip surface finish and friction between the roll and strip to improve
their models of rolling for on-line control or for optimising mill
scheduling. Work at Cambridge has developed micromechanical models of the
contact between the roll and strip, including the roles of hydrodynamic
lubrication and asperity deformation. Spectral analysis of the strip
surface is used to examine the behaviour of different wavelengths of
roughness. In the aluminium industry the strip is made steadily brighter
as it is reduced in thickness from the ingot. For stainless steel,
however, a very rough surface is generated relatively near the finished
gauge, due to the annealing, pickling, descaling and shot-blasting
operations required. For this operation, the focus of research has been to
identify and model the elimination of micropits. Finally the talk will
describe how tribological models can be coupled with mechanical models of
the roll bite, including the elastic deformation of the rolls needed for
to model thin foil rolling.
