Effects of NaOH Solution Concentration on Corrosion Resistance of Fe-Cr-Mo-C-B Amorphous Alloy Coatings

Abstract:

The electrochemical corrosion behavior of Fe44Cr16Mo16C18B6 amorphous alloy coatings in different concentration NaOH solutions (10%, 20% and 30%) at room temperature was evaluated by electrochemical polarization curves, EIS, and scanning electronic microscopy (SEM). Potentiodynamic experiment shows that the coatings exhibit a second wide passive region in the polarization curves, and the passive region gradually gets narrower with the increase of NaOH concentration. The EIS of Fe44Cr16Mo16C18B6 amorphous alloy coatings are composed of high-frequency inductive loop and low-frequency capacitance arc. The corrosion phenomenon of Fe44Cr16Mo16C18B6 amorphous alloy coating can be better interpreted by R(RL)(Q(R(CW))) equivalent circuit model. SEM observation shows that the shed corrosion products of Fe44Cr16Mo16C18B6 amorphous alloy coatings get thicker with the increase of NaOH solution concentration.

Key words:amorphous alloy coatings; polarization curves; EIS