Cailiao Baohu (Mar 2024)
Corrosion Resistance of Fe<sub>69.9</sub>Cr<sub>22.6</sub>Mo<sub>5.7</sub>Cu<sub>0.6</sub>Zr<sub>0.1</sub>Nb<sub>0.8</sub>W<sub>0.3</sub> Amorphous Alloy in Chlorine-Containing Solution at Different Temperatures
Abstract
In order to study the corrosion performance of iron-based amorphous alloys in chlorine-containing solution at different temperatures, Fe69.9Cr22.6Mo5.7Cu0.6Zr0.1Nb0.8W0.3 amorphous ribbons were prepared using arc melting combined with vacuum melt spinning. The effect of temperature on corrosion resistance of alloy in chlorine-containing solution was studied by potentiodynamic polarization curves, impedance spectroscopy and immersion tests. Results showed that, compared to 316 stainless steel, the alloy possessed a typical amorphous structure, and its corrosion resistance was significantly enhanced. In a 3.5% (mass fraction) NaCl solution at 25 ℃, the corrosion resistance of its free surface was comparable to that of the roll surface, with the self-corrosion current density being approximately 18.9% and 15.7% of that of 316 stainless steel, respectively. The alloy exhibited stable passivation characteristics in the NaCl solution, but with a wider passivation range ΔE. At 45 ℃ in the NaCl solution, the difference in corrosion resistance between the free surface and the roll surface significantly increased, the self-corrosion current density notably increased, and ΔE showed little change. In a 37% hydrochloric acid solution at 80 ℃, its corrosion rate increased by two orders of magnitude compared to the condition at room temperature, yet it remained significantly lower than that of 316 stainless steel by two orders of magnitude. The increase in temperature led to a rise in the number of active sites on the surface of the amorphous alloy, enhanced the penetration ability of chloride ions, and accelerated the corrosion reaction rate.
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