Effects of production parameters on mechanical properties of thermomechani̇cally rolled dual phase steel

regard to automotive applications due to their attractive combinations of mechanical properties. For the automotive/heavy transportation industry, these steels are primarily used for underbody components, which require good press formability and ductility as well as acceptable surface appearance despite in most cases being hidden away. In addition to developing steels that satisfy customer requirements, the additional challenge facing strip steel producers of today is in the production of a hot rolled coil with optimum mechanical properties that satisfy the demands of the final application (i.e. fitness for purpose), whilst causing minimal disruption to rolling practices or increasing costs. In this study, effect of rolling and coiling temperature in thermo mechanical controlled process (TMCP), on the microstructure and mechanical properties of dual phase (DP) steel according to martenzite volume fraction (MVF) rate was investigated. By using various finishing mill exit temperature and cooling conditions that is controlled laminar cooling system, the microstructural evolution of coil improves the mechanical properties with lower costs and higher productivity, in comparison to the heat treatment after rolling. The main part of the paper contains the result of tensile, yield and microstructure properties of DP600 steel produced on hot strip rolling plant and run- out table line. The results show that a higher MVF and an increasing cooling rate after the last deformation raised strength of the DP600 steel. The yield strength and ultimate tensile strength increase by decreasing coiling temperature.