Effect of the elastic deformation of rolls on the surface texture transfer in skin-pass rolling

Abstract

This paper investigates the surface texture transfer with elastically deformed work rolls in skin-pass rolling. A numerical approach was developed to efficiently overcome the multiscale challenges associated with the numerical characterisations. To couple the microscale plastic deformation of strip surface asperities with the microscale elastic deformation of roll surface asperities, a specific method was first developed to generate the characteristics between normal contact pressure and interface separation. To deal with the three-dimensional deterministic rough surfaces, a material redistribution scheme was used to predict the plastic deformation of the strip surface asperities and a discrete fast Fourier transform algorithm was employed to efficiently calculate the elastic deflection of the roll surface asperities. These enabled the subsequent multiscale analysis in coupling the microscale interface contact with the macroscale deformation of the metal strip and work roll. As such, the stick/slip transition in the rolling bite due to the elastic deformation of the roll as well as the surface topography of the rolled strip have been quantified. The new method has successfully revealed the effects of elastic roll deformation, roll radius, and strip thickness/roughness on the resultant surface texture of strips in skin-pass rolling.