Microstructural characteristics and texture of hot strip low carbon steel produced by flexible thin slab rolling with warm rolling technology

The mechanical properties and development of microstructure and texture of a low carbon steel produced by Flexible Thin Slab Rolling (FTSR) with warm rolling technology were investigated using scanning electron microscopy, transmission electron microscopy, electron back-scattered diffraction and X-ray diffraction etc. The microstructural features in the hot strip are mainly large polygonal ferrite grains with very few or hardly any pearlite colonies. The values of yield strength and tensile strength are in the range of 215–240 MPa and 305–335 MPa, respectively, and the elongation is in the range of 33–41%. The ferrite softening can be attributed to ferrite recrystallization. Even though the dominant bulk texture is the typical recrystallization texture, which can be grouped into the ND fibre ({111}<110–112>) having a <111> axis parallel to the normal direction, a weak {110}<112> transformation texture was also observed in the final microstructure by electron back-scattered diffraction. By analysis, the large grain size is explained in terms of ferrite recrystallization and relevant growth mechanisms, and the ferrite recrystallization can be considered to play a major role in determining the grain size in the microstructure of the low carbon steel produced by FTSR with warm rolling technology.