用1Cr18Ni9Ti钢板制作立窑烟囱

机立窑在煅烧熟料过程中产生大量的含尘烟气,粉尘含有碱氯硫化合物,它们对金属构件有强烈的腐蚀作用。由于烟气相对湿度较大,金属构件也会从烟气中吸附潮气并在表面形成溶膜,生成盐类溶液。尤其是在配料时掺有萤石,烟气中含有腐蚀性极强的F-,加剧了烟囱的腐蚀。使用δ=6m m普通     

金属构件的腐蚀疲劳裂纹扩展研究现状

在腐蚀环境下服役的金属构件经常遭受腐蚀与疲劳的协同作用,从而发生腐蚀疲劳。本文阐述了腐蚀疲劳的特征;对力学、环境、材料特性等因素对腐蚀疲劳裂纹扩展的影响进行总结;讨论不同的腐蚀疲劳裂纹扩展速率模型;同时提出有待于解决的问题。     

铜在5%过氧化氢消毒剂溶液中的腐蚀行为

新冠疫情期间双氧水(H₂O₂)等氧化型消毒剂的大量使用容易使金属构件产生腐蚀。采用电化学阻抗谱(EIS)、极化曲线、弛豫时间分布法(DRT)和微观形貌表征等方法对铜材料在5%过氧化氢消毒剂溶液中的腐蚀行为进行了研究。结果表明：在过氧化氢溶液中，铜表面呈现全面腐蚀的特征，不会出现腐蚀坑等局部腐蚀的现象。阴极还原过程是H₂O₂消毒剂溶液中铜腐蚀反应的控制步骤。阴极Tafel斜率随温度的升高而增大，腐蚀速率随着增加。腐蚀反应过程中，O₂扩散过程的弛豫时间更长，说明O₂扩散过程是过氧化氢腐蚀反应的重要控制步骤。研究结果有望增加大众对新冠防疫措施下的双氧水消毒剂腐蚀金属构件的认知。     

奥氏体不锈钢应力腐蚀破裂研究的新进展

金属构件在制造、装配、使用过程中,总会受到不同程度的内应力,若在某些特定的环境中使用,就可能发生应力腐蚀破裂。由应力腐蚀破裂造成的破坏事故很多,根据     

化工机械设备腐蚀原因及防腐措施浅析

化工机械设备大多采用金属构件,而金属易产生电化学腐蚀及化学腐蚀。分析化工机械设备腐蚀的内在原因(包括设备自身防腐蚀性能、结构设计、零件表面粗糙度等)与外在原因(包括介质的腐蚀性、介质流速与温度、外部环境条件等),并从设备选材、设计、制造、涂刷防腐涂料、电化学防腐、加强维护管理等方面入手,阐述化工机械设备的防腐措施。     

循环冷却水中的微生物腐蚀危害及其控制

<正> 微生物对金属构件的腐蚀现象早在30年代末及40年代初便开始了研究。人们发现埋在地下的金属管线如水管、油管、供气管等时常发生泄漏,是什么原因造成这些金属管道泄漏的呢?经过分析和研究证明这些管道是被细菌所腐蚀。许多报告指出不但埋在地下的管线受到微生物的腐蚀,就是地面上的建筑物如水库的金属框架、桥梁、海上码     

配方均匀设计对甲醇汽油系统腐蚀抑制剂的优化

针对甲醇汽油在燃烧贮运过程中对金属构件造成的腐蚀问题,采用失重法,对45钢在含0.01mol/L甲酸的M45甲醇汽油系统中进行腐蚀抑制剂配方筛选。应用配方均匀设计实验,采用数据处理系统(DPS)软件通过二次多项式逐步回归,最终得到稳定模型。优化得到的六组元配方对45钢的缓蚀效率可达到94%以上,是一种优良的腐蚀抑制剂,可适用于中低比例甲醇汽油体系。     

海洋环境下飞机结构涂层的耐腐蚀性能研究

在海洋环境下服役的飞机，由于长期遭受海水、盐雾等恶劣环境的影响，极易造成飞机结构的腐蚀。为了提高飞机结构的耐腐蚀性能，采用等离子喷涂与激光熔覆两种技术在304不锈钢基体表面制备了铁基非晶涂层，借助扫描电子显微镜、X射线衍射仪、维氏硬度计等仪器考察了涂层的微观组织形态和显微硬度。在模拟海水的腐蚀环境下，通过测量极化曲线和电化学阻抗谱，探究了铁基非晶涂层的腐蚀行为。结果表明，这两种表面技术制备的铁基非晶涂层都具有良好的耐腐蚀性能，可以降低飞机结构的腐蚀速率，从而保障飞行运行安全。     

藤壶的啓示

对于海上的构筑物和船舰来说,藤壶是一种危害较大的附着生物,由于它们的大量附着不仅会大大降低船舰的航行速度,而且还会破坏金属构件上的保护涂层引起严重的腐蚀。为此,人们对防止海生物的附着问题     

国外航空工业用涂料的一些情况

飞机结构中采用大量的各种金属和非金属材料,其中主要是铝合金和各种钢材。飞机的零件和蒙皮断面小,因此腐蚀作用将大大破坏它们的强度。飞机可能在各种不同气候条件的地区飞行,腐蚀问题具有更重要的意义。     

埋地金属供水管道外壁腐蚀研究

在调查分析埋地供水管道腐蚀状况及腐蚀原因的基础上,通过实验室实验和现场测试,分析了埋地供水管道外部腐蚀结构成分,证明了电化学腐蚀和微生物腐蚀是引起埋地供水管道腐蚀的主要原因。     

Nanostructured coatings approach for corrosion protection

Nanostructured surface treatment coatings based on the Self-assembled Nanophase Particle (SNAP) approach were investigated as potential replacement for chromate-based surface treatments on aircraft aluminum alloys. In the traditional sol–gel method, hydrolysis-condensation processes are followed by condensation polymerization upon film application. This process sequence provides a low temperature route to the preparation if thin coatings which are readily applied to most metallic substrates. The recent discovery of a method of forming functionalized silica nanoparticles in situ in an aqueous sol–gel process, and then cross-linking the nanoparticles to form a thin film, is an excellent example of a nanoscience approach to coatings. This Self-assembled Nanophase Particle (SNAP) process can be used to form thin, dense protective organic surface treatment coatings on Al aerospace alloys. The ability to design coating components from the molecular level upward offers tremendous potential for creating multifunctional coatings.

The important components of Al alloy corrosion inhibition by chromate are storage and release of Cr^VI species, inhibition of cathodic reactions (primarily oxygen reduction), and inhibition of attack at active sites in the alloy. Unlike chromate-based treatments, current SNAP coatings provide barrier-type corrosion resistance but do not have the ability to leach corrosion inhibitors upon coating damage and minimize corrosion of the unprotected area. In this study, organic inhibitors were tested for corrosion protection of aluminum alloys in combination with the (SNAP). Scanning Vibrating Electrode Technique, anodic polarization, electrochemical impedance spectroscopy, and salt spray test were used to study this new approach for chromate replacement.     

国内在役宽体客机腐蚀损伤情况调查与分析

收集了两种常见型号(A型、B型)的39架国内在役宽体客机近10年的腐蚀损伤数据,明确了在役宽体客机结构中易腐蚀的区域。分析了机龄和环境因素对腐蚀的影响,不同区域的腐蚀频率差异,以及结构用材的差异对腐蚀发生频率的影响。结果表明,宽体客机结构腐蚀频率随定检周期的进行具有周期性变化。处于不同机场环境区域的宽体客机在结构腐蚀频率上有显著的差异。厨卫结构和货舱区域由于其专门的使用功能而发生了较为频繁的腐蚀。A型宽体客机在客舱座椅与地板区域由于采用了铝合金与碳纤维复合材料混用的情况,因而发生腐蚀的频率明显高于B型宽体客机。     

Monitoring of crevice corrosion with the electrochemical frequency modulation technique

In this work, it is investigated whether electrochemical frequency modulation can be used to monitor crevice corrosion. With this novel technique, a potential signal consisting of two sine waves of different frequencies is applied to a corroding system. As a corroding system is non-linear in nature, the ac-response will contain non-linear components at harmonic and intermodulation frequencies. Analysis of these components can give information about the corrosion behavior of the system under investigation like the uniform corrosion rate. Crevice corrosion has been investigated by measuring the so-called “causality factors”, which are calculated from the ratio of the current components in the ac-response.According to ASTM standard G48, crevice corrosion has been investigated under the rubber band and cylindrical TFE-fluorocarbon block. Tests were also conducted by creating crevice between circular boundary of metallic sample and epoxy in which metal is engraved. Thus, three patterns of crevice corrosion have been used to see the response of causality factors for AISI 304. Besides some simulations with a simple mathematical model, experiments with artificial crevices were carried out in chloride containing water. The results show that in most cases these causality factors do change when the system goes from uniform corrosion to crevice corrosion.     

EIS study of corrosion behavior of metallic materials in ethanol blended gasoline containing water as a contaminant

In the present paper, the effects of ethanol as a gasoline additive and water as a contaminant on the corrosion behavior of metallic components of a fuel delivery system were investigated. Electrochemical impedance spectroscopy (EIS) testing was performed in both water-free and water contaminated gasoline containing 0%, 5%, 10% and 15% ethanol without the addition of any supporting electrolyte. The surface of the specimens examined in 10% ethanol blended gasoline was observed by scanning electron microscope to understand what types of corrosion attack occurred. The results revealed that the addition of ethanol to gasoline fuel decreased the solution resistance and polarization resistance values of the specimens, resulting in an increase in the corrosion rates of these specimens in ethanol blended gasoline. Water contaminant caused a decrease in the polarization resistance of the ferrous specimens, whereas the observed behavior in others was reversed. Among the investigated metallic materials, the brazing alloy fared the best while Al 6061 alloy showed satisfactory corrosion resistance compared to the rest of the materials in both water-free and water-contaminated ethanol blended gasoline. Moreover, no localized attack was observed in corrosion products.     

飞机蒙皮局部腐蚀的原位快速修复工艺

采用电刷镀设备对飞机硬铝合金蒙皮表面局部的腐蚀进行阳极化，然后实施喷漆，从而达到了原位快速修复的目的。介绍了快速修复的原理及工艺过程、采用间隙盐雾试验考察了修复层的耐蚀性能结果表明，飞机铝舍金蒙皮修复后耐蚀性能为处理前的4倍，使用寿命得以延长：     

Steel corrosion in simulated carbonated concrete pore solution its protection using sol–gel coatings

The corrosion features of polysiloxane hybrid films deposited on carbon steel substrates by dip-coating are compared. Sol–gel coatings were prepared by condensation and polymerization of TEOS/MPTS, TEOS/MTES, TMOS/MPTS and TMOS/MTES mixtures in three molar ratios to assess the influence of their components. The corrosion protection of the coatings was evaluated by means of polarization curves and electrochemical impedance spectroscopy measurements. Coating thickness and composition were quantified by field emission scanning electron microscopy equipped with an EDX analyzer. The results show that all the coatings improved the corrosion resistance of carbon steel in a carbonated synthetic solution, with especially improved protective properties in the case of the TMOS/MTES mixture. These best properties could be due to a highly cross-linked network and greater adhesion to the metallic surface, restricting the corrosion attack.     

Die Arten der rißbildenden Korrosion und ihre Bedeutung für die Betriebsbereitschaft von Komponenten der Chemietechnik

Kinds of crack-producing corrosion and their significance for the availability of components of chemical plants. Interor transcrystalline cracks in metallic components of chemical plants can occur under the combined influence of mechanical stress and corrosion. Since they usually remain unrecognized before the occurrence of visible damage – leakage of a vessel or fracture of a structural part – such crack-producing corrosion processes are greatly dreaded. Based on differences in the mechanism of the process of damage, one distinguishes two groups, i. e. stress corrosion cracking (SCC) and corrosion fatigue (CF). SCC stands for an interaction between local corrosion attack and quasi-static tensile stresses (load- and/or residual stresses). CF means a combination of mechanical stresses differing in time and corrosion. Hydrogen induced SCC is a special kind of crack corrosion, initiated by atomic hydrogen absorbed in a metal. The paper describes the different systems of SCC and CF, the forms of failure, the parameters, and the possibilities of avoiding damages, especially emphasizing their significance in practice.     

Embedded electrode electrochemical noise monitoring of the corrosion beneath organic coatings induced by ac-dc-ac conditions

The degradation of urethane topcoat/epoxy primer systems used for military aircraft and industrial applications were monitored using the electrochemical noise method and measured with embedded electrodes. The degradation was induced by the ac-dc-ac method. The trend in the noise resistance parameter was consistent with the trend in the low frequency impedance modulus obtained from electrochemical impedance spectroscopy experiments. The localization index was not informative about the corrosion mechanism. However, the two shot noise parameters, average charge of event and event frequency, were able to characterize the corrosion process beneath the coating. There was a change from uniform corrosion to localized corrosion on the metal substrate associated with the aircraft coating as indicated by the decrease in frequency event as this coating failed. There was an increase in the charge per corrosion event of the substrate of the industrial coating indicating that the uniform corrosion occurring became more severe as the coating failed.     

工业循环冷却水中金属的腐蚀与腐蚀控制(Ⅰ)

讨论了循环冷却水系统中金属腐蚀控制的指标和金属腐蚀的机理;重点讨论了金属腐蚀控制的方法以及金属腐蚀控制用的缓蚀剂—亚硝酸盐、正磷酸盐、聚磷酸盐、磷酸酯、有机膦酸、锌盐、硅酸盐、钼酸盐、硼砂和芳香唑类。