Corrosion Behavior of Thermally Sprayed NiCrBSi Coating on 16MnR Low-Alloy Steel in KOH Solution
Corrosion Behavior of Thermally Sprayed NiCrBSi Coating on 16MnR Low-Alloy Steel in KOH Solution
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DOI：
10.1007/s11665-016-2012-9
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发表时间：
2016-03
影响因子：
2.3
通讯作者：
Q. Zeng;J. Sun;W. Emori;S. L. Jiang
中科院分区：
文献类型：
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作者：
Q. Zeng;J. Sun;W. Emori;S. L. Jiang
选用NiCrBSi涂层作为防护材料，在16 MnR低合金钢基体上进行空气等离子喷涂。采用极化电阻（Rp）、动电位极化曲线、电化学阻抗谱和全浸腐蚀试验研究了16 MnR基体和NiCrBSi涂层在KOH溶液中的腐蚀行为。电解质是具有不同KOH浓度的溶液。NiCrBSi涂层在KOH溶液中的耐蚀性上级16 MnR涂层。在一定浓度的KOH溶液中，16 MnR基体的腐蚀电流密度是NiCrBSi涂层的1.7-13.0倍。相比之下，NiCrBSi涂层的Rp为基体的1.2-8.0倍，表明NiCrBSi涂层的腐蚀速率远低于16 MnR基体。在相同条件下，NiCrBSi涂层的电容值和总阻抗值远高于16 MnR基体。结果表明，NiCrBSi涂层的耐蚀性优于16 MnR基体，与极化曲线结果一致。NiCrBSi涂层在KOH溶液中对16 MnR基体具有良好的保护作用。腐蚀产物主要为Ni/Fe/Cr的氧化物。
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 (Rp), 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,Rpof 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.