Microstructural analysis of galvannealed coating by grazing-incidence X-ray diffraction

摘要

A technique for identification of phases on galvannealed coatings on extra low carbon and interstitial free steel sheets is presented using a combination of electrochemical stripping method and a grazing incidence angle X-rays diffraction. The different Zn-Fe phases show characteristic corrosion potentials, which can be observed as plateaus in the galvanostatic diagram. It was found that the extension of these plateaus are directly related to current density, and so the value of 2 mA/cm~2 was the best one for this system. The small depth of the incident beam to grazing-incidence X-Ray diffraction have allowed the identification of the different Zn-Fe phases on the galvannealed coating.