Wear of roll surface in twin-roll casting of 4.5% Si steel strip

The rolls are one of the most important components of the twin-roll casting process, determining not only strip quality, but due to their expense, add to the price of the as-cast strip. The potential for reducing operational cost and ensuring required strip quality may be achieved through a reduction in wear of the roll surface and hence reduced frequency of roll surface reconditioning and replacement. To achieve this, it is imperative to understand the mechanisms of roll surface wear which occur during casting operations. The present study was aimed at determining the influence of liquid metal, roll separation force and strip incline from the vertical casting direction on the wear of the roll surface in a twin-roll casting process. It was found that roll wear in the twin-roll casting process is accompanied by removal of material from the roll surface and redistribution of topography of the roll surface. Applying high roll separation forces lead to increase erosion of the roll surface and coarsening of the roll surface topography Roll surface wear caused by deformation occurs by imprinting of the strip surface on the roll surface as well as grinding of the roll surface by the strip. Even with the application of high roll separation forces the highest contribution to wear of the roll surface is by the interaction of the melt with the roll surface in the very early stages of solidification.