The corrosion kinetics behavior of Dacromet coating was studied by potentiodynamic scan,galvanostatic charge and fast triangular voltage methods.The corrosion kinetics parameters were calculated and the semiconductor ...The corrosion kinetics behavior of Dacromet coating was studied by potentiodynamic scan,galvanostatic charge and fast triangular voltage methods.The corrosion kinetics parameters were calculated and the semiconductor conductivity of the coating was investigated.The superior anticorrosive effect of the coating can be attributed to the multilayer inactivation that greatly increases the breakthrough potential and prolongs the breakdown time.On the other hand,the conductivity of the coating could allow the metal powder within the coating displaying sacrificial protection effect at the expense of anade controllably for steel substrate in salt water environments.The coating formed by substituting boric acid for a part of chromic anhydride in the coating solution,contained more charge carriers and showed more negative corrosion potential,so that the coating still effectively displayd such protection effect even in fresh water.展开更多
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 ...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.展开更多
文摘The corrosion kinetics behavior of Dacromet coating was studied by potentiodynamic scan,galvanostatic charge and fast triangular voltage methods.The corrosion kinetics parameters were calculated and the semiconductor conductivity of the coating was investigated.The superior anticorrosive effect of the coating can be attributed to the multilayer inactivation that greatly increases the breakthrough potential and prolongs the breakdown time.On the other hand,the conductivity of the coating could allow the metal powder within the coating displaying sacrificial protection effect at the expense of anade controllably for steel substrate in salt water environments.The coating formed by substituting boric acid for a part of chromic anhydride in the coating solution,contained more charge carriers and showed more negative corrosion potential,so that the coating still effectively displayd such protection effect even in fresh water.
文摘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.
