Corrosion Behavior of Thermally Sprayed NiCrBSi Coating on 16MnR Low-Alloy Steel in KOH Solution

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• 作者：Q. Zeng ; J. Sun ; W. Emori ; S. L. Jiang
• 刊名：Journal of Materials Engineering and Performance
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：25
• 期：5
• 页码：1773-1780
• 全文大小：1,270 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistryr>Characterization and Evaluation Materialsr>Materials Sciencer>Tribology, Corrosion and Coatingsr>Quality Control, Reliability, Safety and Riskr>Engineering Designr>
• 出版者：Springer New York
• ISSN：1544-1024
• 卷排序：25

文摘

NiCrBSi coatings were selected as protective material and air plasma-sprayed on 16MnR low-alloy steel substrates. Corrosion behavior of 16MnR substrates and NiCrBSi coatings in KOH solution were evaluated by polarization resistance (R_p), potentiodynamic polarization curves, electrochemical impedance spectroscopy, and immersion corrosion tests. Electrolytes were solutions with different KOH concentrations. NiCrBSi coating showed superior corrosion resistance in KOH solution compared with the 16MnR. Corrosion current density of 16MnR substrate was 1.7-13.0 times that of NiCrBSi coating in the given concentration of KOH solution. By contrast, R_p of NiCrBSi coating was 1.2-8.0 times that of the substrate, indicating that the corrosion rate of NiCrBSi coating was much lower than that of 16MnR substrate. Capacitance and total impedance value of NiCrBSi coating were much higher than those of 16MnR substrate in the same condition. This result indicates that corrosion resistance of NiCrBSi coating was better than that of 16MnR substrate, in accordance with polarization results. NiCrBSi coatings provided good protection for 16MnR substrate in KOH solution. Corrosion products were mainly Ni/Fe/Cr oxides.Keywords16MnRAPScorrosionKOHNiCrBSi coating