钛钢复合板在海水中电偶腐蚀研究

电偶腐蚀电位接近碳钢自腐蚀电位,不随面积比的增大而变化;电偶腐蚀电流密度和腐蚀深度,随阴阳面积比的增加成倍增大。钛钢复合板制设备一旦内层钛局部腐蚀穿孔,钛与碳钢形成大阴极小阳极的电偶对,很大的电偶腐蚀电流密度作用在碳钢上,使碳钢加速腐蚀,造成设备早期失效。     

钛/碳钢电偶腐蚀和阴极保护研究

用电化学法研究了钛/碳钢电偶在海水中的腐蚀和阴极保护。得出阴、阳极面积比与电偶阳极碳钢腐蚀速度和保护电流密度、保护电位、保护度之间的影响关系。     

高温冷却水系统中有机膦羧酸(PBTCA)缓蚀阻垢性能的研究

采用电偶腐蚀试验和静态阻垢试验 ,研究了高温 (85± 2℃ )冷却水系统中有机膦羧酸 (PBTCA)的缓蚀阻垢性能。试验结果表明 :PBTCA对铸铝 碳钢电偶腐蚀具有优良的缓蚀效果 ,而对铸铁 碳钢、焊锡 黄铜、黄铜 铜电偶腐蚀的缓蚀作用不大 ;PBTCA阻垢性能优良 ,浓度在 5mg/L时阻垢率就可达到 90 %     

导静电涂层的不当应用及隐患

导静电涂层具有导电(含导静电)和较碳钢相对正的电位等电化学行为,与碳钢接触构成腐蚀电偶,碳钢存在产生电偶腐蚀的因素,当涂膜表面电阻率≥1011Ω时,可能对石油储罐运行构成安全隐患。     

电化学噪声研究碳钢在高温环烷酸中的腐蚀行为

以南帕斯凝析油混炼减二线油品为研究对象,通过添加一定比例环烷酸,考察酸值对20#碳钢在高温油品中的腐蚀影响;采用电化学噪声(EN)分析不同温度下碳钢在高温环烷酸中腐蚀状况。结果表明,20#碳钢受高温环烷酸的腐蚀速率随温度的升高呈现出先增大后减小的规律;随酸值的增大,碳钢的腐蚀速率一直增大。在环烷酸的酸值为10 mg KOH/g,流速为1 m/s时,碳钢在280℃时腐蚀速率最高。     

电化学噪声研究碳钢在高温环烷酸中的腐蚀行为

以南帕斯凝析油混炼减二线油品为研究对象,通过添加一定比例环烷酸,考察酸值对20#碳钢在高温油品中的腐蚀影响;采用电化学噪声(EN)分析不同温度下碳钢在高温环烷酸中腐蚀状况。结果表明,20#碳钢受高温环烷酸的腐蚀速率随温度的升高呈现出先增大后减小的规律;随酸值的增大,碳钢的腐蚀速率一直增大。在环烷酸的酸值为10 mg KOH/g,流速为1 m/s时,碳钢在280℃时腐蚀速率最高。     

Zn／A3钢在海水中电偶腐蚀的研究

研究了金属Zn与A3钢在海水中偶接时的电偶腐蚀行为。考察了偶接时间、溶液中Cr浓度、电偶对中阴阳极面积比、实验温度等因素对阳极腐蚀速度的影响。结果表明：偶接时间为24h时,腐蚀速度趋于稳定。腐蚀速度随温度升高,溶液中Cr浓度的增大;阴阳面积比的增大,A3钢的腐蚀速度会相应减慢。     

温度对碳纤维复合材料与金属间电偶腐蚀电流的影响

研究了温度对T700碳纤维复合材料(CFRP)与不锈钢和6061铝合金之间的电偶腐蚀的影响,以及电偶腐蚀电流及其腐蚀速率对材料表面形貌的影响。结果表明:CFRP与6061铝合金在氯化钠(NaCl)电解质溶液体系中会发生电偶腐蚀,而CFRP与不锈钢在NaCl电解质溶液体系中则会发生较小的电偶腐蚀;随着温度的增加,CFRP与6061铝合金发生的电偶腐蚀电流、平均电偶腐蚀速率相应增大,表面腐蚀现象更加严重;在NaCl电解质溶液体系中电偶腐蚀作用对CFRP影响不大,CFRP基本没有受到腐蚀。     

NaCl溶液中铜和A3钢接触腐蚀的研究

研究r金属铜与A3钢在NaCl溶液中偶接时的接触腐蚀行为。考察了偶接时间、溶液中cl-浓度、电偶对中阴阳极面积比、实验温度等因素对阳极腐蚀速度的影响。结果表明,腐蚀速度随温度升高、溶液中Cl-浓度的增大、阴阳极面积比的增大而增大;偶接时间为24h时,腐蚀速度趋于稳定。     

NaCl溶液中铜和A_3钢接触腐蚀的研究

研究了金属铜与A3钢在NaCl溶液中偶接时的接触腐蚀行为。考察了偶接时间、溶液中Cl-浓度、电偶对中阴阳极面积比、实验温度等因素对阳极腐蚀速度的影响。结果表明,腐蚀速度随温度升高、溶液中Cl-浓度的增大、阴阳极面积比的增大而增大;偶接时间为24 h时,腐蚀速度趋于稳定。     

Galvanic studies related to the use in desalination plant of corrosion-resistant materials

Galvanic currents and potentials have been measured for bimetallic couples involving carbon steel, three grades of stainless steel, 90 Cu/10 Ni and titanium when exposed to seawater in the laboratory at temperatures of 18C and 60C and varying oxygen content. The galvanic currents flowing between couples consisting of two of the corrosion-resistant materials were very small. The galvanic corrosion rate of carbon steel, when connected to one of the other materials, was dependent upon the cathodic-polarisation characteristics of the noble-material surface with indications that, at a given area ratio, the galvanic corrosion of carbon steel was greater when coupled to the 90 Cu/10 Ni alloy than when connected to stainless steel or titanium. The usual effects of increasing the anode/cathode area ratio were observed and data were obtained to demonstrate quantitatively the significant beneficial effect of coating the cathode in a bimetallic couple. Intermediate air exposures were not found to promote any large, long-term, effects on galvanic corrosion. There was evidence that galvanic corrosion rates were very small when the dissolved oxygen content was controlled at low levels and some interesting aspects of galvanic corrosion at the higher temperature were noted.     

Localized corrosion of carbon steel in a CO2-saturated oilfield formation water

In this work, corrosion and localized corrosion behavior of X65 pipeline steel were studied in a simulated, CO₂-saturated oilfield formation water by various electrochemical measurement techniques, including electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curves, galvanic current and localized EIS (LEIS). The morphology and composition of the formed corrosion scale were characterized by scanning electron microscopy and energy-dispersive X-ray analysis. A conceptual model was developed to illustrate the occurrence of localized corrosion of the steel under scale. Both galvanic current and LEIS measurements showed that a galvanic effect existed between the bare steel and the scale-covered region. The scale-covered region served as cathode and the bare steel site as the anode. The big cathode vs. small anode geometry accelerated the local corrosion reaction. At an elevated temperature, a compact, crystalline scale was formed on the steel surface, enhancing the galvanic effect. Moreover, the stability of the scale was increased with time, and localized corrosion of the steel under scale experienced mechanistic changes with time.     

TiCN and metallic coatings for corrosion protection of separator plates in MCFCs

Stainless steel 304 substrates were coated with different materials in order to find a suitable coating material for corrosion protection of separator plates in molten-carbonate fuel cells (MCFCs). Five titanium carbonitride coatings differing in composition and morphology and a titanium monoxide coating were deposited with chemical vapour deposition techniques. Also double-layer coatings of TiN/Au and TiN/Ni were prepared. The coatings were tested on their corrosion protection of separator plates in four different environments: under MCFC-cathode or anode gas, at load or at open circuit conditions. The corrosion behaviour was characterized using cyclic voltammetry. Corrosion rates were determined with electrochemical methods and cross-section analyses of corrosion layers. Titanium nitride coatings showed the best corrosion protection. The titanium carbide and titanium monoxide coating showed respectively less and no protection. The thin gold and Ni-coatings were unstable. Under cathode gas, the most important corrosion protection is given by keeping the cell at load, and then a titanium nitride coating might provide lifetime protection. Under anode gas, corrosion is most severe at load conditions. A titanium nitride coating also gives corrosion protection, but not enough for lifetime protection.     

盐酸介质中头孢硫脒对碳钢的缓蚀作用

采用动电位极化曲线和交流阻抗实验,研究了抗生素——头孢硫脒的缓蚀剂在盐酸介质中对碳钢的缓蚀性能和缓蚀作用机理。结果表明,头孢硫脒对碳钢在1.0 mol/L盐酸溶液中具有良好的缓蚀性能,当头孢硫脒浓度为0.4 mmol/L时,缓蚀率达86%以上,为抑制阴极反应为主的混合型缓蚀剂。头孢硫脒在碳钢表面的吸附符合Langmuir等温式,属于单分子层吸附,其吸附行为是以化学吸附为主的物理和化学混合吸附。     

碳钢—硝酸体系腐蚀与缓蚀行为研究

采用失重法、容量法和电化学方法研究了碳钢在50g/kg HNO_3中的腐蚀行为,并对Lan-5在碳钢—50g/kg NHO_3体系中的缓蚀行为进行了初步探索研究.实验结果表明:碳钢在50g/kg HNO_3中的阳极腐蚀产物是Fe~(3+),阴极反应主要不是析氢反应.Lan-5是碳钢—50g/kg HNO_3体系的高效缓蚀剂,其缓蚀效率可达到99.9%,缓蚀剂之间具有显著的协同作用.研究结果还发现,碳钢在硝酸—Lan-5介质中有孔蚀倾向,阳极极化加速孔蚀的形成.     

Theoretical and experimental study of galvanic coupling effects between carbon steel and stainless steels

The use of stainless steel in high corrosion risk areas represents a viable option for reducing the life-cycle cost and extending the service life of concrete structures. However, the possible galvanic corrosion between it and carbon steel continues to be a concern. In this article, the galvanic coupling behaviours of carbon steel and three different stainless steels were investigated in simulated pore solutions and concrete specimens. The results showed that the oxygen reduction reaction was much lower on stainless steel than on passive carbon steel, leading to a lower galvanic coupling current between stainless steel and corroding carbon steel than that between passive and corroding carbon steels. However, rust contamination of stainless steel was found to increase galvanic coupling corrosion on carbon steel.     

电解合成丁二酸的研究进展

综述了国内外电解合成丁二酸的方法,详细介绍了电解反应过程中阴极材料、阳极材料、电解槽结构和隔膜材料的发展趋势.分析结果表明铅及铅合金阴极凭借其自身的优势,仍然是工业生产所采用的最主要的阴极材料;最适合的阳极材料是钛基氧化钌、铱或钽铱钛合金;而且无需使用任何形式的隔膜;未来最具有应用前景的研究方向是Ti或Ti/TiO2阴极.