Corrosion resistance of Fe-based amorphous alloys

Fe-based amorphous alloys can be designed to present an attractive combination of properties with high corrosion resistance and high mechanical strength. Such properties are clearly adequate for their technological use as coatings, for example, in steel pipes. In this work, we studied the corrosion properties of amorphous ribbons of the following Fe-based compositions: Fe66B30Nb4, [(Fe0.6Co0.4)(0.75)B0.2Si0.05](96)Nb-4, [(Fe0.7Co0.3)(0.75)B0.2Si0.05](96)Nb-4, Fe56Cr23Ni5.7B16, Fe53Cr22Ni5.6B19 and Fe50Cr22Ni5.4B23. The ribbons were obtained by rapid solidification using the melt-spinning process, and were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and optical (OM) and scanning electron microscopy (SEM). The corrosion properties were evaluated by corrosion potential survey and potentiodynamic polarization. The Cr containing alloys, that is the FeCrNiB type of alloys, showed the best corrosion resistance properties with the formation of a stable passive film that ensured a very large passivation plateau. (C) 2013 Elsevier B.V. All rights reserved.