The estimation of phase fractions in a galvannealed steel sheet using independent component analysis

Several iron–zinc phases are usually present in a galvannealed steel sheet. Since manufacturers require the identification of phases for the most suitable coatings, the quantitative determination of phase fractions is necessary. There are some qualitative and quantitative methods for phase analysis, but the quantitative procedure of obtaining phase fractions is not available. By using the independent component analysis applied to the X-ray diffraction spectra of galvannealed steel sheets, the present phases were identified by extracting a pure spectrum of each phase. Furthermore, a procedure for estimating phase fractions was proposed, which is based on the regression model subject to the non-negativity constraint on coefficients. Simulation experiments were carried out to demonstrate the performance of the proposed approach.