Skin-pass rolling

  • Kijima, Hideo (Project Participant)

    Project Details

    Description

    Skin-pass rolling is the final forming step of the production of cold rolled steel sheet performed to avoid Lüder band formation, ensure required tolerances and tailored surface texture.

    The process has quite different parameter settings than conventional plate rolling due to small reductions (app. 1%), large contact length compared to the sheet thickness and large roll radius compared to the contact length. Furthermore, skin-pass rolling is usually performed under dry friction conditions, which lead to high friction between the material and the work rolls causing severe inhomogeneous deformation. Skin-pass rolling has great influence on mechanical material properties and resulting dimensional tolerances as well as resulting surface topography of the cold rolled sheets, which are tailored to meet stringent customer requirements for subsequent sheet forming applications.

    In spite of the large influence on final properties the skin-pass rolling process has not been subject to much fundamental research. The lecture describes a two years study on the subject carried out at IPL-DTU together with Professor Niels Bay.

    By elasto-plastic FEM analysis skin-pass rolling has been modelled showing the deformation to be highly inhomogeneous. An extended sticking region in the roll gap is determined together with the boundary between the sticking and the sliding region, where heavy plastic deformation is concentrated in the surface. The location of the transition between the sticking and the sliding region is strongly influenced by the coefficient of friction. The influence of process parameters such as friction, reduction and texture of roll surface on the resulting texture of the rolled plate is shown quantitatively. The numerical predictions are shown to be in good accordance with experimental analysis.
    StatusFinished
    Effective start/end date01/11/200431/10/2006