Ali Cem Taşdemir*, Onuralp Yücel

The iron and steel industry has had a strategic importance throughout history. In recent years, with the development of technology and sectoral competition, new investments have been investigated. One of them is Interstitial-Free (IF) steels. Interstitial-Free Steel, containing very small amounts of carbon and nitrogen, is used in the production of automotive interior and exterior panels. IF steel structures have high formability. This feature has been obtained by removing interstitial atoms such as C and N in vacuum degassing method. In addition, remaining of these elements can be stabilized in steel by adding Ti and/or Nb. After the steel production process is completed, the slab is heated to a certain temperature in the heating furnace. The finishing and coiling temperatures are also important factors in determining the deep-drawing capability. These parameters help in obtaining the coarse TiC and NbC precipitates and the high r value, which is an important indicator of fine-grained structure, high ductility and formability. In this study, the effect of process parameters on IF steels in electric arc furnace steel production, secondary metallurgy processes and hot rolling are explained. Also, the effect of microstructures of steel samples with different chemical compositions and thicknesses on mechanical properties was investigated. In addition, the samples taken from the hot rolled coil were examined under scanning electron microscope (SEM), and texture analysis was performed with electron backscatter diffraction (EBSD) technique. Particularly, the microstructure investigations have shown that Ti and/or Nb is the critical element in terms of ensuring the formability, so interstitial atoms are not formed