双一[γ一（三乙氧基硅）丙基]四硫化物处理热镀铝锌层的耐蚀性研究

采用双-[γ-(三乙氧基硅)丙基]四硫化物(BTESPT)硅烷钝化液对热镀铝锌钢板进行了钝化处理.研究了在5%NaCl溶液中未钝化、硅烷钝化及铬酸盐钝化热镀铝锌钢板的极化曲线和电化学交流阻抗谱.通过中性盐雾试验比较了硅烷钝化膜与铬酸盐钝化膜的耐蚀性能.结果表明:经硅烷钝化液钝化后的热镀铝锌钢板,其腐蚀电位和电流密度下降,极化电阻增大,硅烷钝化膜抑制了热镀铝锌钢板的腐蚀过程,使得耐蚀性能远远高于铬酸盐钝化后的热镀铝锌钢板.     

Corrosion behavior of lanthanum-based conversion coating modified with citric acid on hot dip galvanized steel in aerated 1 M NaCl solution

Rare earth conversion coating is one of the most promising substitutes to the toxic chromate coating. The corrosion resistance of lanthanum conversion coating modified with citric acid on hot dip galvanized (HDG) steel was investigated in aerated 1 M NaCl solution by means of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements. Equivalent circuits were subsequently developed from the measurements to elucidate the corrosion behavior of the coating. The surface morphology of the lanthanum conversion coating was observed by scanning electron microscopy (SEM), and the chemical composition of the coating was characterized by energy dispersive spectroscopy (EDS). The results showed that the corrosion process of the modified lanthanum conversion coating consisted of three stages. The overall corrosion resistance of the coating was excellent.     

A comparative study of molybdate/silane composite films on galvanized steel with different treatment processes

Two types of molybdate/silane composite films were obtained on the surface of hot-dip galvanized steel sheets by either directly immersing in a solution containing silane and molybdate as additive (single-step process), or firstly immersing in a molybdate solution, then in a silane solution (two-step process). The chemical compositions and microstructures of the films were examined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and reflection absorption infrared spectroscopy (RAIR). The corrosion resistances were investigated by electrochemical measurements and neutral salt spray (NSS) test. The results showed that the molybdate/silane composite film formed in the single-step process had a similar double-layer structure as that obtained in the two-step process. The inner layer was composed mainly of the elements O, Mo, Zn, and P, similar to the single molybdate film; whereas the outer layer was composed mainly of the elements C, O and Si, similar to the single silane film. Compared with the single molybdate or silane film, the corrosion current of the composite films was reduced and the impedance of the films was increased. Accordingly, the corrosion resistance of the composite films was remarkably enhanced to a level which was comparable to or even surpassing that of the conventional chromate passivation film.     

热镀锌钢表面硅烷膜耐蚀性能的初步研究

将热镀锌(HDG)钢板经不同的表面处理后涂覆硅烷,研究成膜后的耐蚀性能。中性盐雾腐蚀试验和5%NaCl溶液中的电化学极化曲线测试表明:涂覆硅烷膜后,能够抑制热镀锌钢板产生白锈,涂覆前的碱处理和Ce3 盐处理能进一步提高膜层耐蚀性;硅烷膜能降低腐蚀速度,尤其是在镀锌层上经Ce3 盐处理后再涂覆硅烷成膜能够明显地抑制腐蚀过程中的阴极和阳极反应,耐蚀效果最好。     

Q235钢表面铈盐掺杂乙烯基三乙氧基硅烷膜制备及耐蚀性能

在Q235钢表面制备铈盐掺杂乙烯基三乙氧基硅烷膜。利用电化学阻抗谱(EIS)确定了最佳铈盐添加量,利用EIS和动电位极化法研究了涂覆掺杂硅烷膜的Q235钢在3.5% NaCl水溶液中的耐蚀性能,利用扫描电镜(SEM)观察了掺杂硅烷膜的表面形貌。结果表明,铈盐最佳添加量为1×10^-3 mol/L,经涂镀掺杂硅烷的Q235钢在腐蚀过程中的阳极反应和阴极反应受到抑制,与空白Q235钢相比其腐蚀电流密度减小近3个数量级,极化电阻提高3个数量级,低频阻抗值提高至少4个数量级。     

装载缓蚀剂的蒙脱土对环氧涂层耐蚀性能的研究

将不同比例的装载缓蚀剂蒙脱土和环氧树脂混合制备出纳米复合环氧涂层。根据电化学阻抗谱 (EIS) 和盐雾实验对涂层的耐蚀性进行表征。结果表明,3%装载蒙脱土环氧涂层的水扩散系数为9.89×10^-11 cm²/s,孔隙率为2.22×10^-8,整个浸泡过程中阻抗值在10⁹ Ωcm²以上,表现出最佳的耐蚀性。     

热镀锌钢表面乙烯基三乙氧基硅烷膜的腐蚀电化学行为

采用开路电位(OCP)、交流阻抗(EIS)和动电位极化法对热镀锌钢表面乙烯基三乙氧基硅烷膜腐蚀电化学行为进行了研究。结果表明,在3.5%NaCl溶液中,涂覆硅烷膜层的热镀锌钢与空白热镀锌钢相比,其低频阻抗值提高至少2个数量级,同时腐蚀电流密度减小1个数量级以上,乙烯基三乙氧基硅烷膜防腐蚀效果良好。     

The corrosion resistance of hot dip galvanised steel and AA2024-T3 pre-treated with bis-[triethoxysilylpropyl] tetrasulfide solutions doped with Ce(NO3)3

The present work aims at evaluating the anti-corrosion behaviour of a novel pre-treatment based on bis-[triethoxysilylpropyl] tetrasulfide (BTESPT) doped with cerium nitrate for application on hot dip galvanised steel and AA2024-T3 substrates. The corrosion resistance was evaluated by electrochemical impedance spectroscopy (EIS) and by the scanning vibrating electrode technique (SVET), during immersion in NaCl solutions. The electrochemical results showed that the pre-treatment provides excellent corrosion protection to the substrates. Furthermore, the results evidenced improved protection comparatively to the use of undoped BTESPT pre-treatments, both for galvanised steel and AA2024-T3. This improvement is most likely due to enhanced barrier properties of the film and additional active corrosion protection originated from the inhibiting action of the cerium-based inhibitor impregnated in the silane matrix.     

热镀锌板表面控制技术

为了提高钢板的耐腐蚀性能,在带钢表面进行热浸镀锌是应用最为广泛的途径之一。影响用户选材及使用的最主要的性能有表面质量、力学性能、焊接性能、成形性能等,特别是表面质量,不仅直接影响镀锌板产品的外观,还会影响产品的使用性能。因此,如何从成分设计、热轧工艺、退火工艺等方面采取有效措施,提高镀锌板的表面质量是热镀锌板生产过程中最重要的技术之一。结合热镀锌生产线的生产工艺,从不同方面介绍了影响镀锌板表面质量的因素,并提出了改善镀锌板表面质量的技术。     

热镀锌层上改进型硅烷膜的耐蚀性能

采用添加钼酸盐和磷酸盐的改进型硅烷溶液处理热镀锌钢板,应用俄歇电子能谱（AES）技术分析了膜层中元素的分布。结果表明,改进型硅烷膜为双层结构,外层是较厚的C-Si-O,内层是Mo-P-O-Zn复合物。通过中性盐雾实验（NSS）、极化曲线和电化学交流阻抗谱（EIS）研究了膜层的耐蚀性能。结果显示,该膜层的耐蚀能力接近于铬酸盐钝化膜,是替代传统铬酸盐钝化的良好选择。     

Analytical characterisation and corrosion behaviour of bis-[triethoxysilylpropyl]tetrasulphide pre-treated AA2024-T3

This work aims at studying the corrosion behaviour of AA2024-T3 pre-treated with bis-[triethoxysilylpropyl]tetrasulphide. Simultaneously, the work investigates the influence of the Cu-rich intermetallic particles on the formation of the silane film. The analytical characterisation of the silane films was performed by Auger electron spectroscopy and X-ray photoelectron spectroscopy. The corrosion performance of the pre-treated substrates was evaluated by electrochemical impedance spectroscopy. Atomic force microscopy associated with Kelvin probe was also used to determine the influence of the silane film on the Volta potential distribution on the alloy surface. The results show that copper present in the intermetallics plays an important role on the film formation.     

镁合金表面铈盐掺杂硅烷膜的腐蚀电化学行为

目的为进一步提升镁合金表面常规硅烷膜的耐蚀性能。方法在γ-氨丙基三乙氧基硅烷溶液中掺杂0.50 g/L硝酸铈,采用简单化学浸渍处理,在AZ91D镁合金基体表面制备了铈盐掺杂硅烷膜。借助扫描电子显微镜(SEM)观察了铈盐掺杂前后硅烷膜的表面微观形貌,通过开路电位-时间曲线、电化学交流阻抗谱(EIS)和中性盐雾试验(NSS)研究了铈盐掺杂对5%Na Cl溶液中硅烷膜耐蚀性能的影响。结果铈盐掺杂硅烷膜比普通硅烷膜更厚且平整,其致密性、均匀一致性较好,完全覆盖了镁合金基体,已看不到磨痕。铈盐掺杂硅烷膜的稳定电位约为-1.31 V,且需要的稳定时间最长。铈盐掺杂硅烷膜具有更大的低频阻抗数值,有效遏制了侵蚀性粒子向镁合金基体的迁移和扩散,避免了镁合金基体发生阳极溶解反应。结论采用向硅烷溶液中添加硝酸铈的方法,能够在AZ91D镁合金表面制备出铈盐掺杂硅烷膜。由于铈离子在某种程度上修复了硅烷膜层中的微裂纹和缺陷,显著提升了硅烷膜的耐蚀能力。     

镀锌钢在东莞大气及模拟大气中的腐蚀行为

采用失重法、金相检验、扫描电镜法(SEM)、X射线衍射法(XRD)、能量色散谱法(EDS)以及电化学阻抗谱法(EIS)研究了镀锌钢在东莞大气环境和模拟大气环境中暴露不同时间后的腐蚀行为。结果显示:在东莞大气中,镀锌钢在暴露早期发生了局部腐蚀,随着暴露时间的延长,腐蚀速率先迅速降低然后逐步稳定,耐蚀性先降低后增强;腐蚀12个月后,主要腐蚀产物为ZnO和Zn4SO4(OH)6;在模拟大气环境中,镀锌钢的腐蚀速率和耐蚀性随时间的变化规律和东莞实地大气暴露试验的结果具有良好相关性。     

Felduntersuchungen mit feuerverzinkten Stahlrohren – Auswertung von Langzeit-Daten

Field corrosion tests on hot dip galvanized steel pipes – Assessment of long term data The degree of metal loss and its time dependence of hot dip galvanized steel pipes in flowing waters were correlated with the water parameters. A good correlation was observed with CO₂ concentration of the water. The higher the initial corrosion rate the higher is in many cases the decrease in corrosion rate with time. This is explained in terms of increased iron oxide content in the protective layers formed after the dissolution of a significant amount of zinc layer. Except phosphates the other water parameters (chlorides, sulphates, nitrates and TOC) do not exhibit any influence. The favourable influence of the iron oxide rich protective layers on the corrosion rate may get lost in waters very rich in carbon dioxide.     

无铬复合钝化膜的微观组织结构及耐腐蚀性能

目的解决热镀锌钢板表面六价铬钝化工艺所产生的环境污染问题。方法以钼酸铵、纳米硅溶胶、单宁酸、硅烷偶联剂KH151和KH792为主要原料配制新型环保的无铬复合钝化液,在镀锌板表面制备钝化膜。采用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线光电子能谱仪(XPS)分析无铬复合钝化膜表面的微观形貌、元素组成和化学成分,用电化学工作站测试Mo元素对镀锌板耐蚀性的影响,使用中性盐雾实验研究不同皮模量时膜层的耐蚀性。结果无铬复合钝化膜中的Mo元素可以抑制微裂纹的产生和发展,阻挡腐蚀性介质向金属基体扩散,提高复合硅烷膜的电阻。复合钝化膜的电化学交流阻抗比硅烷钝化膜提高了1.6倍,与六价铬钝化膜接近,可以有效抑制腐蚀电化学反应的发生,降低反应速度,提高膜层的耐蚀性。皮膜量为892 mg/m2时,膜层的腐蚀面积为0,耐蚀性达到六价铬钝化膜水平;皮膜量为1252 mg/m2时,耐蚀性能优异。结论制备的无铬复合钝化膜结合了硅烷钝化膜和钼酸盐钝化膜两方面的优点,提高了膜层的致密性和结合性,膜层耐腐蚀性接近/达到了六价铬钝化的效果。     

镀锌钢板铈盐钝化的电化学性能研究

采用稀土铈盐钝化工艺对镀锌钢板进行了钝化处理.比较了镀锌钢板在0.5mol/L的NaCl溶液中钝化前后的极化曲线、电化学交流阻抗谱.研究了铈盐钝化膜的耐蚀性能,并根据阻抗谱特征建立了腐蚀等效电路.结果表明:经铈盐钝化处理后的镀锌钢板,其腐蚀电流密度下降、极化电阻升高,稀土铈盐钝化膜抑制了镀锌钢板的腐蚀过程,经铈盐钝化处理后,镀锌钢板的耐蚀性能优于空白试样,接近低铬钝化处理样品的耐蚀性.同时,简要分析了稀土铈盐对镀锌钢板的钝化机理.     

镀锌钢板钛盐/硅烷复合膜的耐蚀性研究

研究了镀锌钢板上钛盐钝化膜、硅烷转化膜、钛盐/硅烷复合转化膜的表面形貌和化学成分,并对比了这3种转化膜与普通铬酸盐转化膜的电化学行为和耐盐雾腐蚀性能。结果表明:镀锌钢板钝化后,腐蚀电流密度降低,极化电阻及交流阻抗得到极大提高;钛盐/硅烷复合膜的耐蚀性已经接近普通铬酸盐钝化。SEM和EIS分析表明,硅烷膜是一层物理遮盖膜。     

国产镀锌钢在不同水环境中的腐蚀行为:II反渗透水和调质水

利用开路电位测量、电化学阻抗谱测试技术,结合微观形貌观察,对比研究了国产镀锌钢板在不同反渗透水中的腐蚀行为,镀锌钢在不同进水盐度所得的反渗透水中的腐蚀失效表现出了相似的电化学特征,通过CaCl2、NaCl和NaHCO3等对反渗透水的水质进行调整,改变了镀锌钢的腐蚀失效历程,这可能与腐蚀产物膜的脱落和附着密切相关。     

硅烷γ-APS协同稀土镧钝化镀锌钢板的研究

    采用γ-氨丙基三乙氧基硅烷（γ-APS）协同稀土镧盐钝化镀锌钢板.通过先在试样表面组装一层γ-APS薄膜,再在膜上沉积稀土镧转化膜制得硅烷稀土复合膜.采用电化学交流阻抗（EIS）、盐雾试验（NSS）检测复合膜耐腐蚀性,结果表明,复合膜的耐腐蚀性能优于单一硅烷、稀土转化膜.原子力显微镜检测结果表明复合膜相对于单一硅烷、稀土转化膜更加均匀,致密.EDS检测表明复合膜主要由N,O,Si,Fe,Zn,La等元素组成,其中复合膜中La元素相对摩尔百分含量是单一稀土转化膜的4倍.分析试验数据得出硅烷预处理试样有利于稀土镧转化膜沉积,硅烷与稀土转化膜发生了协同作用,增强了复合膜耐腐蚀性能.初步探讨了复合膜成膜和耐腐蚀机理.     

硅烷偶联剂处理对富锌涂层行为的影响

 采用测量涂层的腐蚀电位和电化学阻抗谱(EIS)等方法研究了硅烷偶联剂处理(钢铁表面的硅烷偶联剂预处理和富锌漆中掺入硅烷偶联剂)对富锌涂层在3.5mass%NaCl溶液中腐蚀行为的影响.结果表明，两种硅烷处理方式均明显延长了富锌涂层的阴极保护期.钢铁表面硅烷处理减弱了无机富锌涂层的阴极保护作用. 