Abstract
It is known that the transcription ratio of roughness in skinpass rolling is varied with various rolling conditions, but the relation between rolling conditions and the conditions of surface roughness of rolled strip is not well known yet. In this paper, zooming method is adopted to a rigid plastic finite element analysis, and applied to dry skin-pass rolling processes of steel to investigate the deformation behavior of the surface of strip. The profile of roll surface shape is modeled from measured profile of electrical discharge machined dull roll (ED model, Ra=2.7 mm) and shot dull roll (SD model, Ra=3.6 mm). Although the reduction of total thickness is small, it is found that the equivalent strain near the surface of strip is considerably large because of the microscopic deformation caused by transcription of the surface roughness. When the reduction is small, the surface roughness transcription ratio with ED model is larger than that with SD model. The transcription ratio increases as the reduction increase, and become almost 100% when the reduction become 6% for ED model, and 10% for SD model. The transcription ratio slightly decreases when the reduction exceeds the peak reduction because of the relative slip between the strip and the roll. The strip materials seem to have little effect on the transcription ratio. The transcription ratio becomes slightly large when the diameter of roll increases.
