宝钢IBF循环水地下水管环境腐蚀状况分析

根据宝钢ＩＢＦ循环水地下水管的特点，结合国内外防止环境腐蚀（土壤、水介质）的方法与经验，选用土壤腐蚀多项指标综合评价法及水介质均匀腐蚀的十级标准等分析方法，通过测定地下水管周围土壤及水介质的理化性质，对宝钢ＩＢＦ循环水地下水管环境腐蚀状况进行了初步分析与评价。     

Beeinflussung von Korrosion und Kavitations-Korrosion in Kühlmitteln durch Inhibitoren

Inhibition of Corrosion and Cavitation-Corrosion in Coolants Based on the results of literature data the properties of modern inhibitors are described. The test results of antifreezes, oils for corrosion protection and chemicals are dealt with. The behaviour of coolants added to these substances in different concentration was studied on corrosion and cavitation-corrosion tests. Furthermore the ageing resistance was determined by simulating motor tests. For use in practice, besides the inhibition effect and ageing resistance the influence of the admixtures on heat transfer, forming of layers, properties of packing materials and maintenance conditions are to be considered.     

A new strategy for corrosion protection of porous stainless steel using polypyrrole films

In this work, a method to improve the protection against corrosion of porous sintered stainless steel is presented. It is based on the electrodeposition of polypyrrole(PPy) layers doped with a large size counterion such as dodecylbenzenesulphonic acid(DBSA), a conducting polymer with high corrosion resistance and good biocompatibility. The efficacy of PPy coating depends on the adequate adhesion between the metal substrate and the coating layer. The protection against corrosion has been tested using 316 L stainless steel(SS) powder sintered at different conditions to evaluate the effect of the sintering atmosphere(nitrogen and vacuum) and cooling rates(furnace and water) on corrosion resistance, while wrought 316 L SS has been used as reference material. In addition, two electrochemical deposition techniques have been tested to select the most adequate. Open circuit potential evolution, anodic polarization measurements and electrochemical impedance spectra have been used to evaluate corrosion protection in phosphate buffer saline medium. It has been evidenced that a more homogeneous and stable coating was obtained in the case of porous stainless steel. The corrosion potential shifted to nobler values and the anodic polarization branch became more stable. Coated porous samples have a good passivation performance with a lower stable passive current density and a higher breakdown potential. The transfer electronic resistance and the impedance module increase more than one order of magnitude. Therefore,the porosity of sintered stainless steel is seen as an advantage for the improvement of the adherence of the PPy coatings. The best corrosion protection is found for samples sintered in nitrogen and water-cooled.     

聚苯胺防腐蚀电化学方法研究

本文综述了国内外在聚苯胺 (PANI)防腐研究中一些常用和新颖的电化学方法 ,指出其测试原理、过程和结果 ,表明PANI有良好的防腐效果。     

低Cr钢在H_2S/CO_2环境中的腐蚀行为研究

运用腐蚀失重和电化学测量技术,研究普通低Cr油套管用钢在模拟塔里木油田环境的H2S/CO2腐蚀行为.结果表明:在模拟CO2腐蚀环境中,Cr元素在腐蚀产物膜中的富集显著改善了膜的保护性,低Cr钢表现出良好的抗CO2均匀腐蚀和局部腐蚀能力;在模拟CO2/H2S腐蚀条件下,H2S腐蚀占主导作用,其均匀腐蚀速率远小于单独CO2腐蚀环境中的均匀腐蚀速率;低Cr材料H2S腐蚀的阳极极化曲线存在较为明显的钝化区,交流阻抗图谱(EIS)拟合的H2S腐蚀极化电阻远大于CO2腐蚀极化电阻.     

Corrosion behavior of friction stir welded AZ31B magnesium alloy with plasma electrolytic oxidation coating formed in silicate electrolyte

A protective ceramic coating of about 50 μm thick on a friction stir welded (FSW) joint of AZ31B magnesium alloy was prepared by plasma electrolytic oxidation (PEO) in silicate electrolyte. Electrochemical corrosion behavior of uncoated and coated FSW joints was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The equivalent circuits of EIS plots for uncoated and coated FSW magnesium alloy were suggested. The corrosion resistance of FSW magnesium alloy depended on microstructure of the FSW joint. The heat-affected zone with severe grain growth was more susceptible to corrosion than the stir zone and base metal. The PEO coating consisted of a porous outer layer and a dense inner layer. The inner layer of PEO coating played a key role on corrosion protection of the FSW joint of magnesium alloy. Meanwhile, corrosion potential, corrosion current density and impedance at different zones of coated FSW joint were almost the same. The PEO surface treatment significantly improved the corrosion resistance of FSW joints of AZ31B magnesium alloy.     

Advanced environmentally friendly coatings prepared from amine-capped aniline trimer-based waterborne electroactive polyurethane

Electroactive waterborne polyurethane (EWPU) containing conjugated segments of electroactive amino-capped aniline trimer (ACAT) unit was successfully prepared and characterized. Iodine-doped EWPU with conductivity 1.2 × 10⁻⁶ S cm⁻¹ was detected. The electroactivity of EWPU was evaluated by performing electrochemical cyclic voltammetry studies. It was worth noting that the EWPU coating was found to exhibit enhanced corrosion protection effects on cold-rolled steel (CRS) electrodes as compared to the corresponding non-electroactive waterborne polyurethane (NEWPU) coating based on a series of electrochemical measurements in 3.5 wt% NaCl electrolyte. A possible mechanism for the enhanced corrosion protection ability of the EWPU coatings on the CRS electrode could be interpreted as the redox catalytic capabilities of the aniline trimer units existed in EWPU induce the formation of passive metal oxide layers on the CRS electrode, as further evidenced by SEM and XPS studies. The thermal stability of EWPU was also investigated by thermogravimetric analysis (TGA).     

Corrosion protection of carbon fibre reinforced aluminium composite by diamondlike carbon coatings

Abstract

Carbon fibre reinforced aluminium exhibits poor resistance against electrochemical corrosion in 3·5 wt-%NaCl solution. Diamondlike carbon (DLC) coatings provide properties which make them interesting materials for external corrosion protection on metal matrix composites (MMCs). The electrochemical corrosion behaviour of uncoated and DLC coated carbon fibre reinforced aluminium was tested in 3·5 wt-%NaCl solution. It has been found that the pitting potential is shifted significantly in the anodic direction and the corrosion current density is much lower due to the presence of the sealing DLC coating. Additionally, scratch tests and SEM studies were carried out in order to characterise the adhesion of the DLC films on the heterogeneous MMCs. Reliable corrosion protection is connected with sufficient coating durability under loading. In order to ensure sufficient loading capacity of the DLC coating under tribological conditions, wear tests were undertaken which revealed a considerable improvement in wear resistance due to deposition of the DLC coatings.     

海洋环境下热喷涂锌、铝及其合金涂层防腐蚀机理研究概况

综述了国内外几十年来在不同海水环境中对热喷涂锌铝及其合金涂层防护性能和机理研究的成果.热喷涂锌铝及其合金涂层在海洋环境中具有优良的长效防护性能,锌具有优良的电化学保护性,铝具有比锌更好的化学稳定性,锌铝合金既保留了锌的电化学特点,又具有铝的化学稳定性能.指出了今后的研究重点应该是金属与有机复合层在浪花飞溅区苛刻腐蚀环境下界面的腐蚀规律和腐蚀机理的探讨,对金属与有机复合层界面的腐蚀原因在理论上做出了本质的解释,并能预测涂层体系的防腐蚀寿命.     

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。     

Cathodic protection revisited: Impact on structural morphology sheds new light on its efficiency

Cathodic protection (CP) has been found as one of the most viable techniques for inhibiting chloride induced corrosion of steel in concrete structures. This contribution specifically pursues exploring the morphological alterations of corrosion products in reinforced mortars under cathodic protection. For this purpose, scanning electron microscopy (SEM) techniques are combined with energy dispersive X-ray analysis (EDXA) and X-ray diffraction (XRD) for microstructural analysis and quantification of the corrosion products. The combined characterisation provides important insight into the structural alterations induced by cathodic protection, and therefore, help to explain the efficiency of CP techniques. Furthermore, electrochemical measurements are employed to monitor the electrochemical process at the steel–paste interfaces. The beneficial microstructural alterations result in better corrosion resistance of the protected specimens, and turn out to be the mechanisms underlying the efficiency of CP techniques.     

Theoretical analysis of the measurement of polarisation resistance in reinforced concrete

Polarisation resistance (R_p) technique based on Stern–Geary equation is one of the most widely used methods of measuring corrosion rate of reinforcement in the field. With the aid of a “sensorised guard ring”, this electrochemical technique is claimed to be able to determine corrosion rate (I_corr) within a given measuring area. However, there are three theoretical problems in the application of this technique: (1) the original Stern–Geary equation is applicable in a uniform corrosion system at its corrosion potential, whereas the reinforced concrete structure may be subjected to non-uniform corrosion or strong polarisation by macro-cell galvanic effects or imposed currents; (2) the value of the parameter B in the original Stern–Geary equation has been estimated to fall within the range 25–52 mV. This may not be suitable for all the corrosion cases of reinforced concrete structures; (3) The polarised surface area of steel may theoretically not always be fully confined by the sensorised guard ring when the cover concrete is too thick.

This paper aims at discussing the theoretical problems. A general relationship between the dissolution rate of steel reinforcement and the measured polarisation resistance is deduced under general conditions. The range of B value is also analysed based on all the possible corrosion situations of reinforced concrete. Furthermore, unsatisfactory confinement by sensorised guard ring on a thick cover concrete is demonstrated.     

防腐蚀涂料性能的电化学检测方法

综述了电位-时间法、交流阻抗法、电化学噪声法以及多重动电位扫描技术等腐蚀电化学方法在评价涂层耐蚀性能中的应用,阐述了电化学方法评价涂层耐蚀性能的基本原理、一般规律和特点,指出电化学方法评价涂层性能具有快速、准确、方便、能提供较多定量和半定量有关涂层失效和涂层下金属腐蚀信息的优点。     

Corrosion Behavior and Protection Efficiency of 2024Al and SiCp／2024Al Metal Matrix Composite

The corrosion resistance of 2024 Al and SiC particle reinforced 2024 Al metal matrix composite(SiCp/2024Al MMC) in 3.5% NaCl solution was investigated with electrochemical method and immersion test, and the corrosion protection of sulfuric acid anodized coatings on both materials was evaluated by electrochemical impedance spectroscopy.The results showed that the SiCp/2024AlMMC is more susceptible to corrosion than its matrix alloy in 3.5% NaCl.For 2024Al,the anodized coating provides excellent corrosion resistance to 3.5%NaCl.The anodized coating on the SiCp/2024Al provides satisfactory corrosion protection,but it is not as effective as that for 2024Al because the structure of the anodized layer is affected by the SiC particulates.     

光伏电站钢制螺旋地桩的腐蚀与防护

电化学腐蚀是威胁光伏电站钢制螺旋地桩使用寿命的重要因素。通过现场试验,研究了强腐蚀土壤环境中牺牲阳极的保护效果,解决了钢制螺旋地桩的腐蚀问题,使之成为真正长寿命钢制螺旋地桩,有利于其在光伏电站领域长期应用。     

航空铝合金大气腐蚀加速试验研究

针对航空铝合金LC4CS的大气腐蚀,采用电化学技术、扫描电子显微镜等方法研究了连续盐雾、周期浸润和综合环境等加速试验.通过户内外试验的比较,对加速试验的模拟性和加速性进行了讨论.结果表明,综合环境试验较好地模拟了大气腐蚀过程中材料表面干/湿循环和电化学特点;同时综合环境试验也较好地模拟了铝合金试样表面的宏观形貌和微观形貌,较好地反映了户外暴露试验的动力学特征.因此综合环境试验是更为合理的加速试验.     

Positive effect of adding aluminum salts to primary coolants of nuclear power installations

With the aim to decrease the ⁶⁰Co content in deposits of activated corrosion products in primary circuits of nuclear power installations, the formation of polymeric hydrolysis products in mixed solutions of Fe(III) + Al(III) + Co(II) nitrates was studied under the conditions simulating the hydrolysis of corrosion products in primary coolants on adding aluminum salts. A study by gel chromatography in combination with radioisotope and elemental analyses showed that the Co(II) ions incorporated in polymeric hydrolysis products in the step of their formation were practically fully replaced by aluminum ions in the course of the polymer aging. Because such polymers are precursors of loose corrosion product deposits formed in primary circuits of nuclear power installations and incorporating the most radiation-hazardous radionuclide ⁶⁰Co, adddition of aluminum salts to primary coolants improves the radiation situation in the maintenance area of nuclear power installations and therefore is appropriate.     

舰船的电化学腐蚀及其外加电流阴极保护法应用状况

舰船在海洋环境下会发生电化学腐蚀,其结果严重影响部队战斗力的提高.实行外加电流阴极保护可以有效防止舰船浸水部分的电化学腐蚀,因而被广泛应用于国内外舰船的保护.介绍了舰船的电化学腐蚀的形成,外加电流阴极保护法的基本原理以及其在国内外舰船上的应用及展望.     

Improvement of the characteristics of corrosion resistance of chemical and petrochemical equipment

We suggest the following methods for the corrosion protection of equipment under the conditions of its long-term service: comprehensive monitoring of equipment accompanied by its reconditioning (suppression of the causes of local corrosion) and electrochemical or complex electrochemical inhibitor protection. We also determined service conditions under which it is possible to use inexpensive carbos steels and cast irons.Severodonetsk Scientific Research Institute of Chemical Machine Building, Severodonetsk. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 31, No. 5, pp. 109–112, September – October, 1995.     

浅谈空调行业中铜铝换热器的腐蚀问题

概述了金属的化学腐蚀及电化学腐蚀机理;分析并实验验证了空调铜铝换热器的腐蚀原因。同时提出了空调铜铝换热器的防腐蚀注意事项。