Abstract: The effect mechanism of chromic anhydride in tension coating of oriented silicon steel was systematically analyzed and studied through the design of experimental research programs and the use of XPS, XRD, TGDSC and FESEM and other analysis and detection techniques. The results showed that the chromic anhydride adding into ingredients of tension coating can help to form gelatinous membrane materials, by using the lowmeltingpoint characteristic of chromic anhydride in the initial stage of heating and curing. And in the indurating stage, the small molecule filmforming materials of phosphates and silica will fill into the trivalent chromium skeleton structure generated by the REDOX reaction of chromic anhydride itself, which can reduce the coating microporous structure and make the coating film more dense. The tension coating combined with magnesium silicate bottom layer can exert tension stress on iron substrate, which can refine magnetic domains and greatly reduce iron loss of silicon steel.

Key words: oriented silicon steel, tension coating, chromic anhydride