Characterization of first generation advanced high strength steel of the complex phase class for automotive application though light optical microscopy and electron backscattering diffraction

As the demand for Advanced High Strength Steels (AHSS) increases, the need for faster and reliable ways to identify their microstructure and quantify the phase distribution becomes more evident. For some types of steels this can be done by a simple color etching and light optical microscopy (LOM) imaging. On the other hand, steels with more complex microstructural distribution require a combination of additional techniques, many of which are time-consuming, such as dilatometry or electron backscattering diffraction (EBSD). In this work, a combination of LOM and EBSD was used to quantify the microstructure of Complex-Phase steels. The methods used to process the data and distinguish the microconstituents in EBSD is explained and some exemplary results obtained in industrial steels are reported. Also, a previously used way to quantitatively compare the LOM and EBSD results is also shown to confirm the validity of the approach discussed in the present work.