The flaked zincc thermosetting coating on steel can exhibit superior anticorrosive effect against fresh water,by substituing boric acid for a poart of chromic anhydride in the coating composition.The mechanism of the anticorrosive activity of this coating was studied with XRD,XPS and NMR measuring techniques.The results show that noncrystalline B 2O 3 and Cr 2O 3 coexist in the voidbetween the zinc particles acting as the binder for the metal powders,and boron is in two forms of tetrahedron and triangle .It is proposed that boron could snatch oxygen atoms from n ZnO layer on the surface of zinc flakes,increase the density of superfluous Zn 2+ and n conductivity of ZnO layer,thus the coating layers still display sacrificial protection effect for steel substrate in fresh water environments.
