Model for the Generation of Surface Topography in Steel Strip Temper Rolling

The surface topography plays an important role in surface quality of cold-rolled steel strip.How surface topography changed in temper rolling is investigated.Based on Ritz method,a new numerical solution of steel strip plastic deformation during temper rolling is developed.Combining it with elastic deformation of rolls,the integration model of rolls and strip is built.Then the elastic-plastic contact between work roll and steel strip is simplified to asperity contact between one rough surface and one ideal smooth surface.The micro models of the generation of steel strip surface topography with pressing-in,furrowing and squeezing are built.The models considered the uplift effect of edges and neighbor role of asperities.Combining two kinds of models mentioned above,a model for the generation of surface topography is established considering asperity contact,roll force,relative sliding displacement between work roll and steel strip.The generation of surface topography of high strength steel strip and the influence of process parameters during temper rolling are studied.The results show that the pressing-in,furrowing and squeezing of work roll asperities on steel strip all influenced the strip surface morphology.The surface roughness of steel strip in the outlet with the changes in tension stress,reduction,roll roughness,roughness of steel strip at the entrance are obtained when pressing-in,furrowing and squeezing are dominant respectively.The following experiments validated the calculation results.