氢氧化钠溶液浓度对Fe-Cr-Mo-C-B非晶合金涂层耐腐蚀性能的影响

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

摘要:

利用电化学极化曲线方法、交流阻抗谱(EIS)技术和扫描电子显微镜(SEM)研究了Fe44Cr16Mo16C18B6非晶合金涂层在不同浓度NaOH(质量分数为10%，20%，30%)溶液中的电化学腐蚀行为。电化学测试结果表明，Fe44Cr16Mo16C18B6非晶合金涂层在NaOH溶液中的阳极极化曲线出现了宽的钝化区，并且发生了二次钝化，钝化区随着NaOH溶液浓度的增大而变窄。EIS图谱由高频感抗弧和低频容抗弧构成，利用R(RL)(Q(R(CW)))等效电路模型能有效地解释此合金涂层的腐蚀性能。SEM观察发现，Fe44Cr16Mo16C18B6非晶合金涂层的表面腐蚀产物随着溶液浓度的增加而变厚，并伴有脱落的现象。

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.