海水介质中复配型水杨醛类席夫碱对碳钢的缓蚀作用

为了研究复配型水杨醛类席夫碱在碳钢表面的缓蚀机理和缓蚀行为,利用电化学方法和表面分析技术测试了碳钢在加入缓蚀剂前后的海水介质中的极化曲线、交流阻抗谱和微观形貌,计算了缓蚀率。结果表明:复配型水杨醛类席夫碱具有明显的缓蚀效果;碳钢表面形成了缓蚀膜,其原子与碳钢表面铁原子相互结合。     

A7N01S-T5铝合金在84消毒液中的电化学行为

为了研究消毒液对高铁车厢铝合金腐蚀的影响,采用动电位极化和电化学阻抗2种电化学测量技术,研究了高铁车体A7N01S-T5铝合金在不同浓度(100,200,400,800,1 000 mg/L) 84消毒液中的电化学行为,取自来水作为对照试验,使用VHX-2000C超景深三维体式显微镜观察试验后铝合金电极的微观形貌。结果表明:电化学阻抗谱中的Nyquist谱电极过程受活化和扩散控制,随着消毒液浓度升高电荷转移电阻和低频阻抗值减小并趋于一致;极化曲线的阴极过程和阳极过程分别以析氢反应和氧化还原反应为主,随着消毒液浓度升高,自腐蚀电位在不断负移后趋于一致,点蚀电位不断负移,腐蚀电流密度逐渐增大后趋于一致;随着消毒液浓度升高合金表面腐蚀由点蚀发展为全面腐蚀,腐蚀区域扩展缓慢,腐蚀速度减缓。     

碳钢在冷凝水中的腐蚀电化学行为

为了给20碳钢在冷凝水中流动加速腐蚀模型的建立奠定基础,在温度、压力可控的密闭腐蚀试验机上运用电化学测试手段(极化曲线、交流阻抗谱)研究20碳钢在不同温度、不同pH值的冷凝水中的腐蚀电化学行为,并通过扫描电镜(SEM)观察腐蚀产物膜形貌.结果表明:在80 ～125℃,pH值7～10的冷凝水中20碳钢的腐蚀反应基本受扩散控制,腐蚀产物膜均多孔疏松,在金属基体和腐蚀产物膜之间构成大阴极、小阳极的腐蚀系统,导致金属基体表面发生点蚀的倾向增大,腐蚀速率升高;pH =7时点蚀温度为90℃,pH =8,9时点蚀温度均为80℃pH=10时点蚀温度为100℃.     

双水内冷发电机空芯铜导线的腐蚀和缓蚀行为研究

电化学阻抗谱和溶液分析的研究结果表明，双水内冷发电机空芯铜导线冷却水的缓蚀剂ＢＴＡ比ＭＢＴ具有更多的优点；用电化学阻抗谱研究低电导介质中铜电极的腐蚀和缓蚀机理能取得令人满意的效果。     

镍基合金825在模拟油气井含CO_2环境中的耐蚀性研究

针对深层油气井开采过程中的CO_2腐蚀问题,采用高温高压釜模拟腐蚀试验和动电位极化曲线、电化学阻抗谱(EIS)等测试手段研究了镍基合金825在苛刻CO_2环境中的腐蚀行为。试验结果表明:镍基合金825在210℃、CO_2分压4.4 MPa的腐蚀环境中,腐蚀速率为0.015 7 mm/a,均匀腐蚀很轻微,表现出良好的抗均匀腐蚀性能;镍基合金825的阳极极化曲线呈现出明显的钝化区,且在120℃、CO_2分压为3.5 MPa条件下存在二次钝化现象;随着温度升高,CO_2分压增大,自腐蚀电位负移,腐蚀驱动力变大; EIS表明电化学阻抗谱有明显的容抗弧特征,电荷转移电阻呈减小的趋势,而钝化膜电容呈减少趋势,电化学腐蚀动力学阻滞性能减弱,降低了镍基合金825在模拟工况中的耐蚀性。     

不同供货状态的6082铝合金的电化学腐蚀行为

为了解模拟融雪剂环境下6082铝合金的电化学腐蚀行为,利用电化学阻抗谱(EIS)和动电位极化曲线等测试方法,研究了不同供货状态下6082铝合金在不同质量分数(0.8％和1.5％)的NaCl溶液中的耐蚀性能,并采用扫描电子显微镜(SEM)与透射电子显微镜(TEM)对电化学腐蚀后的试样进行了微观组织形貌观察分析.结果 表明:6082铝合金电化学阻抗谱中的Nyquist曲线由双容抗弧构成,频率-相位角Bode谱出现2个特征峰;溶液的浓度与铝合金的供货状态对极化曲线中腐蚀电流密度产生很大影响.在NaCl浓度一定的情况下,6082铝合金T6态的耐蚀性能要优于T1态;在供货状态一定的情况下,随着NaCl溶液浓度升高,6082铝合金耐蚀性能降低;6082铝合金的电化学腐蚀特征为由局部点蚀引起的大面积晶间腐蚀.     

触变成形AZ91D镁合金在NaCl溶液中腐蚀行为的电化学分析

用动电位极化曲线和电化学阻抗谱的方法对触变成形AZ91D镁合金在NaCl水溶液中腐蚀行为进行了研究.结果表明:在相同浓度的NaCl水溶液中,随着腐蚀时间的延长,开路电位逐渐提高(正移),同一腐蚀电位下触变成形AZ91 D镁合金的阳极极化电流明显减小,电化学阻抗谱(EIS)显示其容抗减小,腐蚀产物在合金表面沉积,对基体金属具有一定的保护作用,因而其腐蚀速度减小;随着溶液中Cl-浓度的增大,开路电位呈下降(负移)趋势,且其开路电位的正移速度较慢,同一腐蚀电位下触变成形AZ91D镁合金的阳极极化电流增大,EIS显示其线性阻抗减小,腐蚀反应的过程加快,所以腐蚀速度增大.     

蒙脱土改性气相缓蚀剂的制备及性能研究

采用蒙脱土对吗啉类气相缓蚀剂进行改性,通过气相防锈甄别试验和气相缓蚀能力试验,对改性气相缓蚀剂进行了防锈性能评定,结果表明,蒙脱土的引入增强了气相缓蚀剂的缓蚀能力.密闭空间挥发减重试验表明,改性气相缓蚀剂的挥发能力有所提高.模拟大气腐蚀水的电化学极化曲线表明,蒙脱土的引入进一步增大了对阳极和阴极电化学过程的抑制作用.     

酸性溶液中Cl-含量和温度对PH13-8Mo腐蚀行为的影响

为了解决在深海油气钻采中出现的酸性环境中对钻采设备的腐蚀问题,结合海洋中油气田的实际环境,在pH值为3的Na2SO4+H2SO4溶液中,采用电化学极化曲线、循环极化曲线、电化学阻抗谱(EIS)结合静态浸泡实验,分别研究了Cl-质量分数(1%、3.5%和7%)和溶液温度(4、25、50和80℃)对马氏体沉淀硬化不锈钢PH13-8Mo电化学腐蚀行为的影响,并采用点缺陷PDM模型结合闭塞电池理论对其腐蚀机理进行了分析.结果表明,随着溶液中Cl-浓度的升高,PH13-8Mo极化曲线中二次钝化的特性消失.溶液中Cl-浓度和温度的升高均使得PH13-8Mo的点蚀电位降低、点蚀保护电位降低,抗点蚀能力下降,腐蚀电流密度增大,钝化电位区间缩短,电荷转移电阻呈指数关系下降,样品表面腐蚀形貌由点蚀发展为全面腐蚀.     

用于川西气田CO2腐蚀控制的缓蚀剂性能的研究

为解决川西气田的CO2腐蚀问题,利用极化曲线法和交流阻抗方法结合失重试验方法对缓蚀剂MC-1在常温常压和高温高压条件下CO2饱和的模拟气井产出水中的电化学行为和缓蚀性能进行了测试.电化学试验结果表明:在两种条件下,加入缓蚀剂后,体系的阳极电流密度都减小,自腐蚀电位都明显正移,缓蚀机理属于"负催化效应";常温常压下存在阳极脱附现象,而且阻抗值比高温高压条件下的大;常温常压下,缓蚀剂在浓度为100 mg/L时其缓蚀效率达到极值,而在极值浓度下,浸泡时间越长缓蚀效果越好.失重试验结果表明,缓蚀剂在高温高压下的效果不如常温常压下理想.     

碳钢用绿色复配气相缓蚀剂的制备

目的 制备一种绿色高效复配气相缓蚀剂,用于金属的防锈包装.方法 选用苯甲酸钠(C7H5CO2Na)、葡萄糖酸钠(C6H11O7Na)、植酸(C6H18O24P6)和柠檬酸钠(C6H5Na3O7)为复配药品,以A3钢和45#钢为实验对象.通过密闭挥发减量实验、气相快速甄别实验电化学实验和湿热实验筛选出缓蚀率最高的复配气相缓蚀剂配方.将确定的最高缓蚀率气相缓蚀剂制成气相防锈纸,与防锈原纸、市售气相防锈纸进行防锈效果对照,对照实验采用扫描电子显微镜(SEM)、能谱仪(EDS)和接触角仪测试.结果 筛选出四元复配组11 g/L苯甲酸钠+11 g/L葡萄糖酸钠+15 g/L植酸+5 g/L柠檬酸钠的缓蚀率最高,对A3钢的缓蚀率达到了94.36％,对45#钢的缓蚀率达到了94.47％.经该防锈纸防护的A3钢和45#钢表面光滑,无锈蚀出现,氧元素含量低,且接触角大于90°,呈现明显疏水性.结论 经过4种缓蚀剂药品的复配筛选,最终确定出了缓蚀率最高的气相缓蚀剂配方为11 g/L苯甲酸钠+11 g/L葡萄糖酸钠+15 g/L植酸+5 g/L柠檬酸钠,且制成的复配气相防锈纸防锈效果优于空白组的防锈原纸以及市售气相防锈纸.     

温度对X90管线钢及其焊缝电化学腐蚀性能的影响

为了明确X90钢的腐蚀变化规律,利用电化学阻抗技术(EIS)和动电位极化测试技术,研究了X90管线钢母材及其焊缝在不同温度下的电化学腐蚀行为。结果表明:在不同温度下,随着温度的升高,X90管线钢母材及其焊缝越容易发生腐蚀,电化学阻抗逐渐减小;母材与焊缝相比,焊缝在溶液中更容易发生腐蚀,且电化学阻抗值小于母材的。     

Electrochemical impedance spectroscopy investigation on indium tin oxide films under cathodic polarization in NaOH solution

The electrochemical corrosion behaviors of indium tin oxide (ITO) films under the cathodic polarization in 0.1 M NaOH solution were investigated by electrochemical impedance spectroscopy. The as-received and the cathodically polarized ITO films were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction for morphological, compositional and structural studies. The results showed that ITO films underwent a corrosion process during the cathodic polarization and the main component of the corrosion products was body-centered cubic indium. The electrochemical impedance parameters were related to the effect of the cathodic polarization on the ITO specimens. The capacitance of ITO specimens increased, while the charge transfer resistance and the inductance decreased with the increase of the polarization time. The proposed mechanism indicated that the corrosion products (metallic indium) were firstly formed during the cathodic polarization and then absorbed on the surface of the ITO film. As the surface was gradually covered by indium particles, the corrosion process was suppressed.     

螺纹钢水基防锈剂的制备及性能

目前建筑用螺纹钢普遍存在易生锈的问题,而普通水基防锈剂严重污染环境,防锈油又会影响螺纹钢与混凝土的握裹力。自制了一种环保型水基防锈剂对螺纹钢进行防腐蚀保护,利用中性盐雾试验、Tafel极化曲线、电化学阻抗谱研究了该防锈剂在螺纹钢表面成膜后的耐蚀性,同时进行露天耐候试验,研究该防锈剂的实际应用效果,并将自制防锈剂的防锈性能与2种市售防锈剂进行了对比。结果表明:自制的防锈剂能显著提高螺纹钢的耐腐蚀电位,降低其腐蚀电流密度和腐蚀速度,缓蚀保护效率达到99.8%;经自制防锈剂保护的螺纹钢在5%NaCl溶液中浸泡96 h后仍具有较大的极化阻抗值,大气暴露防锈期超过2个月。     

Streptomycin: A commercially available drug as corrosion inhibitor for mild steel in hydrochloric acid solution

The corrosion inhibition of mild steel in 1 M HCl solution by Streptomycin has been studied by Tafel polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurement. The inhibitor showed 88.5% inhibition efficiency at optimum concentration 500 ppm. Results obtained revealed that inhibition occurs through adsorption of the drug on metal surface without modifying the mechanism of corrosion process. Potentiodynamic polarization studies suggest that it is a mixed type of inhibitor. Electrochemical impedance spectroscopy techniques were also used to investigate the mechanism of corrosion inhibition.     

Corrosion Behavior of SiCp／2024 Al Matrix Composites in 3.5 wt pct Sodium Chloride

The influences of volume fraction and particle size of SiC particulate reinforcements on the corrosion characteristics of SiCp/2024Al metal matrix composites in aerated 3.5wt pct NaCl aquecus solution were investigated.The electro-chemical behavior was investigated by prtentiodynamic polarization and electrochemical impedance spectroscopy, the general corrosion behavior of the composites was studied further by immersion tests.The results showed that pitting susceptibility was about the same for the composites and the alloy.The corrosion potentials were also independent of SiC phase.The corrosion resistance for the composites decreased as the volume fraction increased or particle size decreased.     

浓硫酸中304不锈钢焊接接头腐蚀行为的电化学研究

为了给应用于浓硫酸工业生产的304不锈钢管道的防护提供指导,采用电化学阻抗谱法与动电位扫描法研究了304不锈钢焊接接头各个区域在质量分数为98%的浓硫酸中不同温度下的腐蚀行为。结果表明:304不锈钢焊接接头在浓硫酸中的腐蚀形式以点蚀为主。在相同条件的浓硫酸介质中,焊接接头各区域耐蚀性优劣依次为:基材、焊缝、热影响区,焊接过程对不锈钢的腐蚀起到促进作用。随着硫酸介质温度的逐渐升高,基材的钝化膜比较稳定,而焊缝与热影响区的钝化膜会发生破裂;并且各区域的自腐蚀电流与腐蚀速率会逐渐增大,耐腐蚀性逐渐下降。     

Acid Cleaning of Steel Using Arghel Echo Friendly Corrosion Inhibitor

Acid cleaning of mild steel dissolution by 1M sulfuric acid/10 % methanol (test solution) in presence of Arghel herb extract as green inhibitor were monitored by potentiodynamic and electrochemical impedance techniques in the temperature range 30–60^oC. At all temperature, the corrosion rate decreased with increasing inhibitor concentration. Potentiodynamic polarization measurements indicated that the inhibitor has strong effect on the corrosion behavior of the steel and behave as mixed type inhibitor. Impedance results indicate that the charge transfer controls the dissolution mechanism of steel across the phase boundary in the absence and the presence of the inhibitor. The inhibition efficiency obtained from various employed methods is in good agreement. Thermodynamic and activation parameters obtained from this study indicated that the presence of the Arghel increases the activation energy, and the adsorption process of the inhibitor on the metal surface is spontaneous.     

An impedance study of two types of stainless steel in Ringer physiological solution containing complexing agents

The effect of complexing agents EDTA and citric acid on the electrochemical behaviour of AISI 304 and orthopaedic stainless steels in Ringer physiological solution was investigated by potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS). The content of Mo has a pronounced effect on the corrosion resistance, as evident by the broader passive range of the orthopaedic stainless steel containing Mo. The addition of complexing agents induces significant changes in polarization and impedance characteristics, i.e., the shift of corrosion and breakdown potentials in a more negative direction, an increase in current density, and a significant decrease in charge transfer resistance. The results were interpreted by the formation of soluble complexes of metal ions with chelating agents, especially EDTA, which suppressed the formation of the outer Fe(III) layer of the passive film. The impact of complexing agent on the electrochemical parameters was found to be related to its concentration in electrolyte and the stability constant of the complex formed with the related metal ion.     

碳钢用双吗啉甲基脲基复配气相缓蚀剂及其缓蚀性能

目的 制备一种用于碳钢保护的绿色高效复配气相缓蚀剂。方法 以双吗啉甲基脲、尿素、十二烷基磺酸钠为三因素,采用45^#钢为研究对象,通过极化曲线和电化学阻抗实验确定三水平,设计L9(3³)正交实验,筛选出最优配方并制成气相防锈纸,采用X射线光电子能谱和接触角测量研究复方VCI在碳钢表面的吸附情况。结果 筛选出了最佳的三元配方:3 g/L双吗啉甲基脲+2 g/L尿素+0.25 g/L十二烷基磺酸钠;以此为基础制成防锈纸,其挂片实验的缓蚀效率高达94.05%。经该防锈纸防护的金属表面接触角与被原纸保护的金属表面接触角相比增大了约11°,呈现出更高的疏水性。结论 以最优气相缓蚀剂配方为基础制成的气相防锈纸具有明显的气相防锈保护作用。