The study of aluminium corrosion in acidic solution with nontoxic inhibitors

The inhibitory activity of some substituted N-arylpyrroles on aluminium corrosion in hydrochloric acid was studied in relation to inhibitor concentration, using potentiodynamic and impedance spectroscopy techniques. All investigated compounds were found to act as cathodic-type inhibitors and inhibition was ascribed to the adsorption of inhibitor onto the electrode surface. The inhibiting efficiency of the additives depended on the inductive power of the groups attached to the benzene and/or pyrrole ring. The carbaldehyde group showed better inhibiting power due to additional condensation on the electrode surface. The impedance results analysed in terms of the polarization resistance showed that the EIS technique can be successfully applied in the determination of corrosion resistance in systems where the corrosion kinetics are not simple.     

The inhibitive action of dimethyltin dichloride towards the corrosion of aluminium in hydrochloric acid and sodium hydroxide solutions

The dissolution of aluminium in hydrochloric acid and sodium hydroxide solutions in the presence of dimethyltin dichloride as corrosion inhibitor has been studied using hydrogen evolution and thermometric methods. The two methods gave consistent results. The higher inhibition efficiency of this compound in acidic than in alkaline media may be due to the less negative potential of aluminium in hydrochloric acid solution, favouring adsorption of the additive. The adsorption of this compound was found to obey Frumkin adsorption isotherm.     

硝酸根离子对铝在盐酸溶液中的缓蚀作用

用失重法和动电位极化曲线方法研究了硝酸根离子对工业纯铝在1．5mol／L HCl溶液中的缓蚀作用和机理,讨论了其在铝表面的吸附。结果表明,对铝在盐酸溶液中的腐蚀,硝酸根离子是很一种很好的缓蚀剂。当硝酸根离子浓度较低时,其缓蚀效率随着浓度增加而增大,随后增加硝酸根离子,缓蚀效率基本稳定;当硝酸根离子浓度较大时,缓蚀效率在测量时间内随着腐蚀时间的延长而增大。硝酸根离子通过抑制铝的阴极反应而起到缓蚀作用,其在铝表面的吸附符合Freundlich吸附等温式。     

盐酸介质中新型缓蚀剂研发进展

对盐酸介质中金属材质腐蚀的机理以及研究现状进行了分析和概述。对缓蚀剂的研发做出了展望。     

酸洗缓蚀剂的应用研究现状及发展趋势

概述酸洗和酸洗缓蚀剂对于热力设备的重要性，综述国内外酸洗缓蚀剂的研究状况及酸洗缓蚀剂的种类，文中针对工业生产中的不同情况，列举了硫酸酸洗缓蚀剂、盐酸酸洗缓蚀剂、氢氟酸酸洗缓蚀剂、硝酸酸洗缓蚀剂的应用现状，并阐明酸洗缓蚀剂的缓蚀机理及其发展趋势。     

阴极保护法对化肥厂中铝材的有效保护

介绍了化肥厂中普遍存在的铝材设备腐蚀问题及相应的腐蚀机理，针对化学药剂难以完全抑制碳化水箱的局部腐蚀，详细介绍了阴极保护方法，并阐述了阴极保护的机理及阴极保护方案，还根据实际经验，重点介绍了具体实施过程中涉及到的问题，如设备尺寸及保护面积的计算、阴极与阳极的布置、设备的表面处理及涂层。为证明此方法的有效性，作者还专门从直观效果和试片检测两方面介绍采用阴极保护的应用效果。理论和实践证明，阴极保护法是保护化肥企业铝材设备的有效手段。     

酸洗过程中的缓蚀剂

通过对近十年来酸洗缓蚀剂的研究工作的介绍与分析,结合清洁生产的要求及定量化计算数据,明确指出酸洗缓蚀剂在酸洗废液减量化的意义,并对进一步研究与开发绿色酸洗缓蚀剂提出值得重视的几个问题。     

盐酸介质金属缓蚀剂最新进展

对盐酸介质中金属材质腐蚀的机理以及研究现状进行了分析和概述。目前,人们认识到金属材质在盐酸溶液中腐蚀速度与酸度和氯离子浓度有关。而针对就盐酸溶液中的氯离子以及氢离子在金属的腐蚀过程发挥多大的功效,以及金属材质的阳杉阴极反应是如何进行的动力学问题的研究成为该领域的主要趋势,以解决金属材料在盐酸介质中腐蚀问题。     

Effect of some substituted anilines‐formaldehyde polymers on mild steel corrosion in hydrochloric acid medium

The influence of linear copolymer of amines and formaldehyde namely poly(aniline‐formaldehyde) (Inh1), poly(o‐toluidene‐formaldehyde) (Inh2), and poly(p‐chloroaniline‐formaldehyde) (Inh3) on corrosion of mild steel in hydrochloric acid was evaluated by weight loss measurements, linear polarization, Tafel polarization, and electrochemical impedance spectroscopy. These polymers showed very high inhibition efficiency at very low concentrations. Results obtained showed that all inhibitors are mixed inhibitors and participate in reaction probably in the form of metal inhibitor complex on metal surface. Atomic force microscopic studies reveal that the surface of metal is quite unaffected after use of inhibitor in hydrochloric acid solution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

盐酸酸洗咪唑啉型缓蚀剂IM的研究

以玉米油为原料合成了一种新型的咪唑啉型缓蚀剂IM ,利用静态失重法测定了该缓蚀剂在盐酸介质中对 2 0A碳钢的腐蚀速度和缓蚀效率 ,探讨了其缓蚀机理。结果表明 ,该缓蚀剂在盐酸介质中对 2 0A碳钢具有较强的缓蚀能力     

Influence of power ultrasound on the corrosion of aluminium and high speed steel

The influence of power ultrasound on the corrosion of aluminium and high speed steel in chloride medium has been investigated. Open circuit potential, polarization curves and electrochemical impedance spectroscopy were employed to study the corrosion process before, during and after ultrasonic irradiation as well as scanning electron microscopy of the corroded surfaces. Cavitation led to formation of pits, erosion and increased mass transport. The effect of ultrasound power, chloride concentration, horn tip–metal distance and of tip diameter were assessed. The principal effect of ultrasound on aluminium is destruction of the oxide film and on high speed steel removal of corrosion products and increased solution mass transport; the influence of ultrasound is greatest at low chloride concentrations. For both metals it was shown that for chloride ion concentrations up to 0.1 M the influence of ultrasound power is most evident, followed by the distance between probe tip and metal, then [Cl^–] and lastly the size of the probe tip. The potentialities of using ultrasound as a rapid diagnostic test of corrosion resistance are indicated.     

Performance assessment of poly (methacrylic acid)/silver nanoparticles composite as corrosion inhibitor for aluminium in acidic environment

This article reports the preparation of poly (methacrylic acid)/silver nanoparticles composite (PMAA/AgNPs) by in situ mixing of aqueous solutions of PMAA and 1 mM AgNO₃ with natural honey as reducing and stabilizing agent. The prepared PMAA/AgNPs composite was characterized by UV–vis spectroscopy, Fourier transformed infrared, X-ray diffraction and energy dispersive spectroscopy (EDS) while the morphology of the AgNPs in the composite was obtained by transmission electron microscopy (TEM). TEM results revealed that the AgNPs were spherical in shape. The performance of PMAA/AgNPs composite as anticorrosion material for Al in acidic environment was examined by electrochemical, weight loss methods, complemented by surface analysis characterization with scanning electron microscopy (SEM), EDS and water contact angle measurements. Results obtained indicate that PMAA/AgNPs composite is effective corrosion inhibitor for Al in an acid-induced corrosive environment. Inhibition efficiency increased with increase in composite concentration but decreased with rise in temperature. From potentiodynamic polarization results, PMAA/AgNPs composite is found to function as a mixed-type corrosion inhibitor. The adsorption of the composite onto Al surface was found to follow El-Awady et al. adsorption isotherm model. SEM, EDS and water contact angle results confirmed the adsorption of the composite on Al surface.     

三元复合硫酸酸洗缓蚀剂对碳钢缓蚀性能的研究

采用失重法研究了2-巯基苯并咪唑、三乙醇胺、碘化钾单独使用时在0.5 mol/L硫酸中对碳钢的缓蚀效果。研究表明,单独使用3种缓蚀剂添加量较大。为了减少缓蚀剂用量,降低成本,进行了三元复配。通过正交及平行实验得到最佳三元复配缓蚀剂,当2-巯基苯并咪唑、三乙醇胺、碘化钾三者质量浓度比为1∶10∶3,总用量为140mg/L时,缓蚀率可达到96.58%。同时对缓蚀剂的缓蚀机理及各组分间的协同作用进行了探讨。     

Effect of curing on the corrosion protective properties of thin organosilane films on aluminium

Film properties and corrosion protection given by thin organosilane films (bis-1,2-(triethoxysilyl)ethane: BTSE) on aluminium were investigated as a function of curing. The thickness was determined using spectroscopic ellipsometry (SE). Impedance spectra, modelled by an electrical equivalent circuit, show three time constants. The variation of the elements in these three time constants as a function of the immersion time in a NaCl solution indicate the structure of the film after curing. It can be concluded that the barrier properties of the organosilane films are influenced more by the curing temperature than by the curing time.     

用铝土矿制备聚合氯化铝的研究

研究了用铝土矿和质量分数为20％的废盐酸为原料。采用两段溶出工艺制备聚合氯化铝的方法。考察了盐酸用量对铝土矿溶出率及碱化度的影响。结果表明：随着盐酸用量的增加。铝土矿溶出率增加，铝土矿与盐酸的最佳比例是l：1．5。     

盐酸酸洗缓蚀抑雾剂MY的研究

研制的一种适用于碳钢在高温盐酸中酸洗除锈的MY缓蚀抑雾剂,是以合成的一种咪唑啉季铵盐与其他化合物复配得到的混合物。采用静态失重法和中和滴定法对其缓蚀抑雾性能进行评价,并对其缓蚀机理进行探讨。结果表明,MY缓蚀抑雾剂在20%盐酸中,酸洗温度为80℃,用量为0.5%时,缓蚀效率达95%以上,抑雾效率达到90%以上,对改善作业环境,综合治理环境污染具有积极的作用。     

Inhibition of copper corrosion in aerated hydrochloric acid solution by amino-acid compounds

The effect of two amino-acid compounds, dl-alanine and dl-cysteine, on copper corrosion in an aerated 0.5 mol l⁻¹ HCl solution was studied by weight-loss measurements, potentiodynamic polarisation curves, and electrochemical impedance spectroscopy. A conventional benzotriazole (BTA) inhibitor was also tested for comparison. dl-cysteine was shown to be the most effective inhibitor among those tested inhibitors. Potentiodynamic polarisation results revealed that both the dl-alanine and dl-cysteine acted as an anodic inhibitor; however, dl-cysteine, in particular, was more effective, as it strongly suppressed anodic current densities. The improved inhibition efficiency of dl-cysteine in the 0.5 mol l⁻¹ HCl solution was due to its adsorption on the copper surface via the mercapto group in its molecular structure.     

Formation and corrosion of InP/In contacts in hydrochloric acid

Flatband potentials, charge carrier concentrations and their frequency dispersions of p-type and n-type InP in 1.0 M HCl were determined. The cathodic decomposition of InP in this acidic solution is compared with the deposition process of indium from 1.0 M-HCl containing 0.1 M InCl₃. The share of the involved reactions, hydrogen evolution, InP decomposition and indium deposition are investigated. The reaction rates are generally smaller on p-type InP and the reaction speed is much slower but the principal reactions are the same. The kinetics of the indium deposition and dissolution are studied in detail. These reactions are discussed in terms of the preparation of watersplitting photoelectrodes with modified surfaces.     

Characterization of a lacquer film formulated with phosphating reagents for corrosion protection of galvanized substrates

This paper analyzes the chemical composition of the interface resulting from the application of an organic coating (lacquer) containing phosphating reagents on galvanized steel, galvanneal, and galfan substrates and its stability after short periods of exposure to condensing humidity and UV light (UVCON test). X-ray photoelectron spectroscopy (XPS) has shown that the lacquer drying process gives rise to a number of discontinuities on the lacquer surface (pores) exposing the phosphate layer formed on the original metallic coating surface. It is interesting to note the detection of fluoride and nitrite ions and phosphoric acid not combined with zinc (perhaps as HPO₄ ²⁻ and H₂PO₄ ⁻) on the lacquered surfaces before testing, which suggests a tendency of these species to concentrate on the outer surface of the phosphate layer or at the lacquer-phosphate layer interface (in zones covered by the lacquer). After one day of exposure to the UVCON test, XPS reveals the disappearance of the fluoride and nitrite ions and of the free phosphoric acid. After 15 days of exposure to the UVCON test, the carbon content is seen to have decreased considerably, while the zinc, phosphorus, and titanium contents have risen. The low atomic percentages of carbon (only moderately higher than those obtained with the coatings in bare state) and Zn/P atomic ratios close to 1.5 suggest the removal of a very substantial percentage of the lacquer, leaving the zinc phosphate formed on the surface of the different metallic coatings exposed. This quick and significant drop in the lacquer content barely seems to have a repercussion on the degradation of the metallic substrate during the UVCON test, since its visual aspect remains unaltered.