Improved Corrosion Resisting Property Of Magnetism Iron Fiber

Iron fibers have been used in every field widely, because they have supervisingproperty and they cost little. But the iron fibers oxidated very easily by reason of theirprimary element iron. The poor ability in anti-corrosion prevents the iron fibers to bemore useful. The disadvantage must be overcome, so that the iron fibers would developfurther and faster.In order to improve the property in anti-corrosion, we use three methods and thenwe test the property of the films. The methods are Cr(Ⅲ) black passivation, Cr(Ⅵ) blackpassivation and coat SiO2to the surface of the iron fibers. Scanning electron microscopywas used to observe the morphology of the films. Elements of passive films areconformed by using EDS. Phase composition of the passivation films after heat treatmentwas identified by X-ray diffraction. The anti-oxidation property was studied bythermogravimetry (TG) analysis and the mean of3％CuSO4solution drip was adopted todetermine the anti-corrosion property.The passivation films obtained from the primary trivalent chromium blackpassivation bath have bright black surface with uniform color. However, the corrosionresistance of the black passivation films was poor for that the CuSO4corrosion time wasonly65s, but the surface of the films were even.Both orthogonal and single factor experiments were carried out to determine thebest scheme of the Cr(Ⅵ) black passivation. The properties of the passivation films weredetected and the results were as follows:1)3％CuSO4solution drip was220s;2) SEMshowed that the surface of the films were even and uniform density;3)Fe, Ni, Cu werefound in the film by the test of EDS. Passivation films with bright color, uniform densityand good corrosion resistance can be obtained.At last we experiment that coated the iron fibers with SiO2, and the experimentresults show:1)3％CuSO4solution drip was240s;2) SEM showed that the surface ofthe iron fiber has been covered with SiO2;3) Si, O were also found in the film as wellas Fe, Ni, Cu by the test of EDS, it indicated the iron fibers have been coated with SiO2successfully;4) The anti-oxidation property of iron fibers coated with SiO2wasbetter than the fibers without treatment obviously;5) It can be testified that the anti-corrosion property of the iron sample coated with SiO2improved significantly than theiron sample without treatment. Passivation films with uniform density and goodanti-corrosion can be obtained.