Perparation Technology and Property of a Low Chromium Dacromet Coating

The preparation technology of a low chromium dacromet coating is introduced. The property and corrosion behavior of the coating were studied by means of polarization curve, electrochemical impedance spectroscopy (EIS) and immersion test. The morphology and composition of the coating were analysed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that during the preparing process, part of chromic anhydride was replaced by inorganic salt, and the corrosion products as a shield could prevent the corrosion medium, and the corrosion resistance was increased. Adding epoxy resin and silane coupling agent could enhance the adhesion on the substrate surface.