摘要
通过动电位极化、电化学阻抗、扫描电镜和X射线衍射仪等研究了SO_(4)^(2-)、NO_(3)^(-)、NH_(4)^(+)对U75V钢轨钢在以FeCl_(2)为基础组分的缝隙腐蚀模拟液中的腐蚀行为的影响。在不同离子种类以及离子浓度环境的溶液中,对U75V钢轨钢进行了阴、阳极极化测试,在自然浸泡条件下进行原位阻抗测试,并对腐蚀形貌进行分析。结果表明:在FeCl_(2)的基础溶液中,钢轨钢前期表现出程度较轻的均匀腐蚀,腐蚀后期出现沟壑状腐蚀坑;而SO_(4)^(2-)在腐蚀前期会加速钢轨钢表面的全面腐蚀,后期对其表面的局部腐蚀有抑制作用;NO_(3)^(-)能抑制阳极的活性溶解并大幅提高了阴极反应速率,对钢轨钢的腐蚀抑制作用明显;NH_(4)^(+)对钢轨钢的腐蚀有促进作用,在腐蚀前期钢轨钢表面就产生腐蚀坑,后期腐蚀坑分布密集。此外,在除氧的模拟液中浸泡的钢表面出现了Fe_(3)C,说明该钢在缝隙腐蚀中容易出现Fe_(3)C在缝内积累的现象。
Effects of SO_(4)^(2-), NO_(3)^(-) and NH_(4)^(+) on corrosion behavior of U75 V rail steel in simulated crevice corrosion environment based on FeCl_(2) were studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), scanning electron microscopy(SEM) and X-ray diffractometer(XRD). A cathodic and anodic polarization test of the U75 V rail steel was carried out in solution with different ion types and ion concentration. In situ impedance test was carried out under natural immersion conditions, and corrosion morphology was analyzed by SEM. The results show that in the FeCl_(2) basic solution, the rail steel shows slight uniform corrosion in the early stage and gully corrosion pit in the later stage of corrosion, while the SO_(4)^(2-) accelerates the overall corrosion of the rail steel surface in the early stage of corrosion, and inhibits the local corrosion on the surface in the later stage of corrosion. The NO_(3)^(-) can inhibit the active dissolution of the anode and greatly improve the cathodic reaction rate, which can inhibit the corrosion of the rail steel obviously. The NH_(4)^(+) can promote the corrosion of the rail steel, and the corrosion pits are produced on the surface of the rail steel in the early stage of corrosion, and become more denser in the later stage of corrosion. Moreover, Fe_(3)C appears on the surface of the steel immersed in the simulated liquid of deoxygenation, indicating that the Fe_(3)C is prone to accumulate inside crevice during crevice corrosion of the U75 V steel.
作者
邓羽
张杰
徐玮辰
DENG Yu;ZHANG Jie;XU Wei-chen(Key Laboratory of Marine Environmental Corrosion and Bio-fouling,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China;School of Shipping and Ship Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Open Studio for Marine Corrosion and Protection,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China;Center for Ocean Mega-science,Chinese Academy of Sciences,Qingdao 266071,China)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2021年第1期155-164,共10页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金国家重大科研仪器研制项目(41827805)
国家自然科学基金(51708541)
山东省自然科学基金(ZR2019QEM011)。
关键词
U75V钢轨
缝隙腐蚀
离子浓度
U75V rail steel
crevice corrosion
ion concentration
