缓蚀剂对船用钢在潮湿大气中的防蚀研究

模拟 90 7A钢在海水的潮湿大气环境和表面覆有薄层缓蚀剂液膜状态下其腐蚀受抑制的情况 ,利用恒电量仪连接ACM控头 ,监测其腐蚀状态 ,结合电化学阻抗谱 (EIS)的测量 ,探讨 90 7A钢在薄层缓蚀剂液膜下的腐蚀受到抑制机理 .结果表明 :此时大气腐蚀反应已转变为阳极过程控制占优势 ,在浸润后期的EIS呈现出由腐蚀介质扩散和电化学放电混合控制特征 ,如果利用恒电量激励下的等效电路模型解析 ,则可以更清楚地获知薄层缓蚀剂液膜下金属表面膜层的信息     

薄层缓蚀剂液膜对907A钢防蚀效果的电化学测量技术

本文研究饱和海水湿气环境中对 90 7A钢施加缓蚀剂的防蚀作用 ,利用恒电量技术等电化学方法对同材质的三电极大气腐蚀监测探头 (ACM )进行腐蚀测量 .结果表明 :利用电化学方法监测薄层缓蚀剂液膜的防蚀效果可以更清楚地获知缓蚀剂成膜的过程 ,并对薄层缓蚀剂液膜防蚀效果作出快速评价     

电化学阻抗谱研究铈盐转化膜形成过程中的影响因素

应用电化学阻抗谱(EIS)连续测试B95铝合金在0.01 mol·L-1CeCl3溶液中铈盐转化膜的形成过程,通过成膜过程中交流阻抗值的变化研究了温度,溶解氧O2的变化对B95铝合金稀土转化膜成膜过程的影响机制,采用等效电路的方式对测试的EIS进行了解析.结果表明:温度在20,25,30 ℃时B95铝合金在0.01 mol·L-1CeCl3溶液中的阻抗谱等效电路与成膜形成阶段的相同;温度为35,40,45℃B95铝合金的阻抗谱与成膜成长阶段的等效电路相同,表明升高温度缩短了稀土膜形成阶段的时间,铝合金基体溶解迅速被抑制;升高温度有利于铈盐氧化膜的形成;通O2对稀土Ce转化膜的形成无明显促进作用,O2参与的反应不是Ce转化膜形成的决速步骤.     

铝合金在铈盐溶液中成膜过程的电化学阻抗谱研究

应用电化学阻抗谱(EIS)研究B95铝合金在0.01 mol.L-1CeCl3溶液中铈盐转化膜的形成过程和机制。结果表明:EIS变化可以清楚地显示B95铝合金在铈盐溶液中成膜的动态过程,稀土转化膜的成膜过程可以分成形成、成长和稳定平衡3个阶段;形成阶段以Al合金的溶解为主;在成长阶段随着时间的增加,转化膜不断增厚,铝合金基体的溶解已经被抑制;稳定平衡阶段,膜的成长与溶解已经达到平衡,通过EIS解析表明自然条件下生成的转化膜不致密,该阶段阻抗谱图等效电路与成长阶段相同,但阻抗谱包含两个时间常数;在成膜三阶段基础上提出了稀土转化膜的成膜模型;同时给出各阶段阻抗谱图等效电路及其阻抗表达式。     

中性介质中铜缓蚀剂的成膜过程

使用光电化学与电化学石英晶体微天平联用（PECQCM）技术对中性介质铜缓蚀剂成膜过程进行了现场研究．结果表明，在中性Na2SO4溶液中钝化型缓蚀剂Na2OrO4对Cu成膜生长有抛物线规律，而由于Cl-的影响，在中性NaCl溶液中，该缓蚀剂膜生长曲线为折线型．沉淀型缓蚀剂Na2SiO3在Na2SO4溶液中的铜晶振电极上不成膜，而在NaCl溶液中可成膜．     

分子结构对咪唑啉缓蚀剂膜在Q235钢表面生长和衰减规律的影响

采用弱极化法、电化学阻抗谱等手段研究了烷基咪唑啉和硫脲基烷基咪唑啉缓蚀剂对Q235钢在饱和CO2盐溶液中的缓蚀行为变化, 探讨了吸附膜的形成与衰减规律. 结果表明, 烷基咪唑啉和硫脲基烷基咪唑啉缓蚀剂都是以控制阳极过程为主的混合界面型缓蚀剂. 在85 ℃下, 烷基咪唑啉成膜相对较慢, 吸附能力较弱, 容易发生脱附; 而硫脲基的引入, 使得硫脲基烷基咪唑啉缓蚀剂溶液存在自动修复能力, 增强了咪唑啉环的吸附性能, 提高了缓蚀剂的缓蚀性能; 硫脲基烷基咪唑啉水解开环后, 成膜性能下降, 膜寿命和缓蚀效率也大大降低. 最后采用量子化学计算对上述结论进行了验证和解释.     

新型缓蚀剂对钻具在31%NaCl溶液中电化学行为研究

将聚醚表面活性剂(P)、硫酸锌、多聚磷酸钠和葡萄糖酸钙复配,制成用于以欠饱和盐水(31%,NaClby mass)作钻井泥浆的缓蚀剂.研究了该缓蚀剂对钻具钢G105的缓蚀作用机理极化曲线和交流阻抗(EIS).测试表明,80℃时该缓蚀剂是阳极型缓蚀剂,成分之间有较好的协同作用,并以总浓度为200×10-6g.L-1时缓蚀效果最好;缓蚀率随时间增加而增大,缓蚀剂在电极表面形成膜的致密度在试验范围内随时间延长而增大.缓蚀剂的作用机理因其浓度改变而不同:低浓度下以几何覆盖效应为主,高浓度下则以成膜为主.     

YKI-05缓蚀剂对不同浸没条件下907A钢的缓蚀性能研究

利用动电位极化方法 ,研究了有机膦酸醇酯类缓蚀剂 (YKI_0 5 )对 90 7A钢在天然海水中的缓蚀行为 .实验表明 :静态海水中 ,浓度为 30 0mg/L的YKI_0 5缓蚀剂能在 90 7A钢表面形成稳定的缓蚀膜层 ,是一负催化阴极型缓蚀剂 ,于实验周期内其对 90 7A钢的缓蚀效率可稳定在 90 %左右 ;在周期性间歇浸没情况下 ,此种缓蚀剂所形成的膜层很不稳定 ,随着间浸次数的增加 ,膜层破损程度愈甚 ,缓蚀效果减弱 ,缓蚀膜对 90 7A钢表面仅仅是个覆盖层 ,起到抑制了部分阴、阳极反应的作用 ,从而可将缓蚀机制归结为覆盖效应     

镁合金表面镧、钐稀土防护膜研究

利用化学转化处理在AZ31镁合金表面制备两种非铈稀土防护膜--镧膜和钐膜.采用电化学阻抗谱(EIS)方法评定膜层的防护效果,采用扫描电子显微镜(SEM)和能量色散谱(EDS)表征膜层的表面形貌及组成.结果表明:镁合金表面镧、钐转化膜均由相应的稀土氢氧化物/氧化物及基体金属氢氧化物/氧化物组成;镧转化膜均匀、致密,对基体金属防护效果好,而钐转化膜呈碎片状,部分覆盖基体表面,防护作用很弱.初步探讨了成膜机制.     

AZ31镁合金表面镧转化膜的形成机制

通过化学浸泡方法在AZ31镁合金表面制备了高防护性镧转化膜。X射线光电子能谱(XPS)对膜组成的测试结果表明:镧转化膜主要由氢氧化镧组成,另外还有少量氢氧化镁及碳酸镧、碳酸镁成分。电化学技术测量成膜过程中试样开路电位(OCP)的变化,分为剧增、降低、缓慢平稳增长3个阶段。原子力显微镜(AFM)对膜层形貌的表征结果表明:镧转化膜最初为均匀致密膜,后出现纤维结构,然后纤维结构不断稳定发展。在上述结果基础上讨论了镧转化膜的形成机制:成膜过程分为紧密层形成、纤维层萌生、纤维层稳定生长3个特征阶段,前两个阶段发生非常迅速,后一阶段持续时间较长,是成膜的主要过程。     

EIS studies of the destruction behavior of a corrosion inhibitor film on carbon steel surface under hydrodynamic conditions

Effect of surface water shear stress on the performance of an inhibitor film used in the carbon steel pipelines for oil and gas product transportation is studied. Experiments were conducted in laboratory by electrochemical impedance spectroscopy (EIS). EIS that was carried out under various rotation rates, different temperature, and immersion time was taken to investigate the behavior of a corrosion inhibitor and the destruction process. Typical EIS spectral changes were acquired during the film destruction processes, and this means that EIS is an effective method for evaluating inhibitor performance and monitoring the film layers’ behavior. Experimental results show that the film layers become more porous with increase in rotation rates and temperature. Therefore, the performance of this corrosion inhibitor decreased resulting from surface shear stress and bubble impact. In addition, scanning electron microscopy (SEM) was also taken to help confirm the inhibitor film structure under different conditions.     

On the application of electrochemical impedance spectroscopy to study the self-healing properties of protective coatings

Active corrosion protection based on self-healing of defects in coatings is a vital issue for development of new advanced corrosion protection systems. However, there is a significant lack of experimental protocols, which can be routinely used to reveal the self-healing ability and to study the active corrosion protection properties of organic and hybrid coatings.The present work demonstrates the possibility to use EIS (electrochemical impedance spectroscopy) for investigation of the self-healing properties of protective coatings applied on a metal surface. The model EIS experiments supported by SVET (scanning vibrating electrode technique) measurements show that an increase of low frequency impedance during immersion in the corrosive medium is related to the suppression of active corrosion processes and healing of the corroded areas. Thus, EIS can effectively be employed as a routine method to study the self-repair properties of different protective systems. The 2024 aluminium alloy coated with hybrid sol–gel film was used as a model system to study the healing of artificial defects by an organic inhibitor (8-hydroxyquinoline).     

铝合金表面改性对有机涂层附着力的影响及腐蚀防护性能研究

利用电化学阻抗（EIS）、扫描微参比技术（SRET）、接触角、粗糙度、附着力、盐雾等测试方法,研究了铝合金阳极氧化与贻贝黏附蛋白（MAP）/CeO₂/硅烷γ-APS（MCA）表面复合修饰的腐蚀防护性能以及对改性聚氨酯涂层附着力和耐蚀性的影响。结果表明,MCA复合膜可抑制铝合金的腐蚀,并具有一定的自修复功能;阳极氧化和MCA表面复合修饰可为铝合金提供有效的早期腐蚀防护作用,且能提高铝合金表面粗糙度和润湿性,显著提升改性聚氨酯涂层在铝合金表面的附着力和耐蚀性,因而结合改性聚氨酯涂层和表面复合修饰可实现对铝合金长期有效的腐蚀防护。     

Effect of Aluminum Alloy Surface Modification on Adhesion of the Modified Polyurethane Coating and Its Corrosion Protective Performance北大核心CSCD

The ordinary organic coatings on aluminum alloy usually encounter a problem of low adhesion to the substrate, which results in destruction and failure of the long-term protective performance of the anticorrosion systems. The surface modification of aluminum alloy is able to enhance the adhesion of organic coating on aluminum alloys, and to improve their protective performance. In this work, a combined surface modification of anodic oxidation and mussel adhesion protein/CeO2/3-aminopropyltriethoxysilane composite film (MCA) was developed on the aluminum alloy. The adhesion of modified polyurethane coated on the treated aluminum alloy and its corrosion protective performance were evaluated comprehensively by using contact angle, adhesion strength, electrochemical impedance spectroscopy (EIS), and scanning reference electrode technique (SRET). The measurements of EIS and SRET demonstrated that the MCA composite film on anodic oxidized Al possessed self-healing function and provided effective protection against early corrosion of aluminum alloy. The pull-off test showed that both anodic oxidation treatment and MCA composite film modification were able to increase the adhesion of modified polyurethane coating on aluminum alloy, and their combined action were supposed to remarkably enhance the adhesion strength up to 17.1 MPa. The reason for the improvement of adhesion was that the anodic oxidation treatment and MCA composite film modification could improve the surface roughness of aluminum alloy, and enhance the surface wettability and surface polarity, which is beneficent to enhance the bonding of the modified polyurethane coating to aluminum alloy surface. The EIS results showed that no any corrosion occurred for the modified polyurethane coating on the treated aluminum alloy during 65 d immersion in 3.5wt.% NaCl solution. The impedance value in low frequency range of the modified polyurethane coating always maintained at a high order of magnitude on the aluminum alloy treated by anodic oxidation and MCA composite film modification, showing an excellent protective performance of the coating system. The evaluation of Neutral Salt Spray (NSS) indicated that the modified polyurethane coating on the treated aluminum alloy owned superior corrosion protection performance, and the adhesion strength remained 13.1 MPa and no any corrosion was found at the scratch locations even after 1200 h of salt spray testing. It was concluded that combination of anodic oxidation and MCA composite film were capable of significantly improving the adhesion of modified polyurethane coating on aluminum alloy and providing long-term effective corrosion protection for aluminum alloy. © 2021 Authors. All rights reserved.     

Electrochemical impedance spectroscopy for characterization of coatings with intrinsically conducting polymers

The method of electrochemical impedance spectroscopy (EIS) was applied to investigate the behaviour of a thin intrinsically conducting polymer film (ICP) deposited on a metal substrate. Especially the conductivity, the redox properties, the anion release properties, and the corrosion protection of a coating with and without ICP film on an iron or steel substrate were studied. Combined with other electrochemical methods, the reactions taking place at an injured surface area of the coated iron were studied. The corrosion protection mechanism of polythiophene could be explained.     

Electrochemical studies for the electroactivity of amine-capped aniline trimer on the anticorrosion effect of as-prepared polyimide coatings

The electroactive polyimide consisting of various content of amine-capped aniline trimers (ATs) have been successfully synthesized and characterized by Fourier-Transformation infrared and UV-visible absorption spectroscopy. The electroactivity of as-prepared polyimides was tested by electrochemical cyclic voltammetry (CV) studies. It was noticed that the as-prepared electroactive polyimide with higher content of amine-capped ATs shows higher electroactivity (i.e., larger redox current) than that of non-electroactive polyimide, leading to enhance corrosion protection efficiency on cold-rolled steel (CRS) electrodes. This enhanced corrosion protection efficiency has been explained based on a series of electrochemical measurements such as corrosion potential, polarization resistance, corrosion current and electrochemical impedance spectroscopy (EIS) studies in 5 wt-% NaCl electrolyte. This significant enhancement of corrosion protection on CRS electrodes as compared to non-electroactive polyimide might probably be attributed to the redox catalytic property of as-prepared electroactive polyimide coatings inducing the formation of passive layer of metal oxide.     

紫铜表面3-巯丙基三乙氧基硅烷薄膜的制备与耐蚀性能

利用傅里叶变换红外(FTIR)光谱分析了3-巯丙基三乙氧基硅烷分别在酸性和碱性的醇-水溶液中水解后以及在紫铜表面成膜后的结构特征. 利用极化曲线、电化学阻抗谱(EIS)和盐水浸泡实验测试了硅烷膜的耐腐蚀性能. 结果表明: 3-巯丙基三乙氧基硅烷在酸性溶液中能够发生一定程度的水解并生成Si―OH结构, 且当该溶液在自然状态下晾干后, 其水解程度进一步增大. 在碱性溶液中该硅烷只发生少量的水解, 溶液中含有较多SiOCH₂CH₃结构, 且在溶液自然晾干后水解程度也没有明显增大. 由酸性硅烷溶液制得的薄膜中硅烷分子以Si―O―Si 键相互交联的程度比由碱性硅烷溶液制得的薄膜高. 硅烷膜降低了紫铜电极的腐蚀电流密度, 其保护效率分别为90.3%(酸性)和79.2%(碱性). 在3.5% (w) NaCl溶液中浸泡24 h后, 由酸性溶液制得的薄膜表现出更高的阻抗值, 而由碱性溶液制得的薄膜则基本失去了对基底的保护能力.     

锈层下碳钢和耐候钢的微区和宏观腐蚀电化学行为

采用扫描电化学显微镜(SECM), 辅以极化曲线和电化学阻抗谱(EIS), 并结合SEM和XRD研究了耐候钢和碳钢在干湿交替环境下的腐蚀行为, 包括微区阳极溶解过程和阴极还原行为、 宏观腐蚀过程和微观结构及组成等. SECM测试结果表明, 锈层下碳钢和耐候钢的腐蚀过程都受阳极控制, 锈层的存在促进氧的还原. 宏观和微区电化学测试结果均表明, 在实验周期内, 初期形成的锈层降低了Fe阳极溶解速率, 从而提高碳钢和耐候钢的耐蚀性能, 后期形成的锈层由于其组成和结构特征的变化, 2种钢的腐蚀速率增加; 同时耐候钢的腐蚀速率较碳钢大, 且氧还原也较碳钢强, 有利于锈层的形成, 从而有利于长期的防护, 但是耐候钢的锈层在短期内并没有很好的保护性. 锈层不够致密, 呈疏松多孔状, 其组成主要有晶态的γ-FeOOH, Fe₃O₄和γ-Fe₂O₃等, 相同的干湿循环条件制备的耐候钢锈层较碳钢厚.     

Corrosion protection of carbon steel using a combination of Zr conversion coating and subsequent zinc-rich silicate coating with a flake ZnAl alloy

To improve the corrosion protection properties of zinc-rich silicate coatings on steel, zirconium pretreatment loaded with (3-aminopropyl)triethoxysilane (APTES) 0.025 % (v/v) and the partial replacement of spherical zinc by flake ZnAl alloy were investigated. DC polarization and electrochemical impedance spectroscopy (EIS) show that the zirconium pre-treated layer containing APTES improves the corrosion protection of the bare steel. Zinc-rich silicate coatings containing flake ZnAl with and without pretreatment were evaluated by EIS, salt spray test and pull-off test. Pretreatment with a zirconium conversion layer reduces corrosion products and adhesion loss (from 16.53% to 12.54%) while the performance of corrosion protection significantly increased from 2003 Ω.cm² to 2640 Ω.cm² in comparison with the non-pretreated samples. The results show that flake ZnAl pigment (5 wt%) significantly improves corrosion resistance and prolongs the duration of cathodic protection of zinc-rich silicate coatings.     

AZ31镁合金表面聚吡咯的化学氧化合成及其耐蚀性能

以对甲苯磺酸钠为掺杂剂, 三氯化铁为氧化剂, 用化学氧化聚合法在AZ31 镁合金表面制备聚吡咯(PPy)膜. 采用傅里叶变换红外(FTIR)光谱分析了镁合金表面聚吡咯膜结构, 通过电化学极化曲线、电化学阻抗谱(EIS)研究了其耐蚀性能, 通过扫描电子显微镜(SEM)、X射线能量散射谱(EDS)分析了表面形貌和成分. 和镁合金裸样相比, 聚吡咯膜对镁合金腐蚀有一定的抑制作用. 硅烷预处理改善了镁合金/聚吡咯体系的耐腐蚀性能, 使腐蚀电位较镁合金裸样正移了110 mV, 电流密度减小了约2个数量级.