Influence of chemical composition and processing conditions on interstitial content of cold rolled ferritic steels

Determining the content of solute elements in cold rolled ferritic steels constitutes an important aspect in metallurgy, since the interstitial elements have a harmful effect on the anisotropy properties (i.e. texture) of the final product, usually steel sheets for automotive applications. Both the carbon and nitrogen contents in solid solution depend on the chemical composition and thermomechanical parameters, such as the coiling temperature (CT) and the cold reduction degree. In the present paper, thermoelectric power measurements technique has been applied to study the relationship between the process variables such as CT and cold rolling reduction, and the amount of interstitial elements in solid solution. It was shown that at high CTs the value of the thermoelectric power only depends on the carbon content in solid solution, meanwhile at low CTs, a second contribution should be considered due to the presence of nitrogen in solid solution.