Effect of Flow Stress Characteristics and Process Condition on Dog-Bone Profile in the Vertical Rolling

Abstract

Vertical and Horizontal rolling in roughing mills are important processes to control width and thickness reduction of slab, respectively. In roughing mills, Horizontal rolling process may lead to width spread. Vertical rolling process controls this phenomenon or reduces width of slab substantially to improve product quality before horizontal rolling. However, the edge of slab is locally deformed during vertical rolling. It causes a kind of formation so called 'Dog-bone'. The dog-bone shape would affect width spread after horizontal rolling. Some models for dog-bone have been developed from several experimental data. But there is no analysis for material properties. In this paper, some materials and process condition are applied to slab and discussed about shape difference. Some materials consist of flow stress values. The flow stress equation is dependent on temperature and chemical composition. The flow stress equation characteristics of each material in vertical rolling are predicted through FE analysis. Verification for FE analysis is also considered.