Q235钢在土壤中宏电池腐蚀行为的研究

在实验室中通过模拟装置对Ｑ２３５钢在土壤中的宏电池腐蚀行为进行了研究。结果表明,饱和／非饱和土壤环境的差异对金属的宏电池腐蚀具有决定性的作用,土壤的电阻率可以影响宏电池的电流分布。     

电化学保护技术及其应用：第三讲 牺牲阳极

1概述 在第二讲中已就阴极保护的原理进行过讨论.从中得知,在作用着的腐蚀电池体系中,接入另一电极,该电极的电位较负,这时这一电极将与原来的腐蚀电池构成一个新的宏观电池.这一较负的电极将是新电池的阳极,原来的腐蚀电池则为阴极,依靠外加阳极不断溶解所产生的阴极电流实现阴极保护.该电位较负的电极称为牺牲阳极,因为随着电流的不断流动,阳极材料不断消耗掉.     

不锈钢焊接接头低倍金相检验的制样方法

对电解腐蚀在不锈钢焊接接头低倍金相检验中的运用进行研究,通过试验选定腐蚀溶液、腐蚀时间和输出电流等参数。结果表明:采用10 mL HNO_3+90 mL H_2O腐蚀溶液,输出电流2 A,在室温下腐蚀6 min,制备出清晰的不锈钢焊接接头低倍金相试样,可清晰显示焊接接头各个区域。     

WBE技术研究水线区Q235碳钢腐蚀

应用阵列电极技术研究了Q235碳钢在3.5%NaCl溶液中的电流分布,并根据电流分布变化过程探究了腐蚀机理。结果表明,浸泡起始阶段,自水线向下,阳极电流呈逐渐增大趋势,表现出宏观氧浓差电池的特征,但此时阴极与阳极电流交叉分布。水线腐蚀发展阶段,形成了以水线附近为阴极,水线下为阳极的氧浓差电池。水线上阴极反应速率的不断增加,推动水线下金属腐蚀由水线下逐渐向水线处扩展,加速了整个金属的腐蚀反应速率。水线腐蚀稳定阶段,水线上成为电极表面主要的阴极反应区域,腐蚀速率处于稳定状态。阵列电极测量技术可以提供整个水线区的电流分布及其变化信息,弥补了传统片状电极的不足,为水线腐蚀研究提供了有效的技术手段。     

AH32长尺试样在模拟海洋潮差区腐蚀行为的电偶电流研究

利用自制的模拟实验装置模拟实海潮差,监测了在模拟潮差区内AH32长尺试样的电偶电流和电极电位变化情况。结果表明,由于供氧差异形成的宏电池作用,AH32长尺试样在潮差区和全浸区内的电极电位分布不均衡,引发了内部的电偶电流,其实质为阴、阳极反应产生的净电流。在潮差区内,AH32长尺试样不同部位的电偶电流随潮位运动发生周期性变化;当潮位最高时,所有部位的电偶电流均处于极大值状态,且中间潮位部位的电偶电流最大,由此所引起的阳极电流也最大。根据电偶电流的变化计算出的干燥、润湿和浸没状态的时间分布表明,AH32长尺试样在潮位区不同部位的腐蚀量取决于润湿和浸没时间在该部位的分配。各部位在浸没态时存在宏电池作用,产生电偶电流。而在润湿态下,由于薄液膜的溶液电阻很大,导致宏电池驱动电位几乎等于在薄液膜上的电压降,因此宏电池作用极弱,且不产生电偶电流。润湿时间和润湿电量的关系显示,潮位运动中AH32长尺试样的最大润湿时间出现在平均中潮位以上的部位,表明因润湿引起的该部位的腐蚀失重最大。结合由浸没态引起的平均中潮位腐蚀失重最大的结果可以确定,在潮水涨落过程中AH32长尺试样的最大腐蚀失重量应出现在平均中潮位偏上的部位,这与腐蚀速率的测量结果一致。     

硫酸盐还原菌对X70钢土壤宏电池腐蚀的影响

利用极化曲线、电化学阻抗、扫描电镜和表面能谱等方法,研究了硫酸盐还原菌对X70钢在土壤中宏电池腐蚀的影响.结果表明,接菌或灭菌粘土和砂土组成的宏电池,砂土中试样为宏电池的阴极,粘土中试样为阳极;随实验时间的增加,接菌及灭菌粘土中自然埋藏X70钢腐蚀速率逐渐减小,而砂土中宏电池阳极的腐蚀速率一直相当高;接菌土壤宏电池的电流和电动势比灭菌的大,接菌及灭菌粘土中阳极的腐蚀速率分别是自然腐蚀速率的4.93和2.45倍;在宏电池阴阳极面积比15∶1情况下,接菌及灭菌粘土中宏电池阳极的腐蚀速率分别为宏电池阴阳极面积比11时的5.01及2.33倍.     

《中国腐蚀与防护学报》1991—1992年主题索引和总目录

主题索引(按关键词第一字笔划顺序排列)两划二氧化硫Fe一20Cr一SAI一0.SY的高温腐蚀12.116Rene80合金受载时的高温腐蚀12,235三划大气腐蚀多孔薄板式气体腐蚀性探测电池11,145材料大气腐蚀数据库11,373阴极保护对耐候钢腐蚀疲劳的影响11,292四划不锈钢氮对双相钢应力腐蚀的影响11,1氮改善双相钢抗应力腐蚀的机理11,9SUS36钢的阳极钝化膜11.125氮注入提高xcr18NigTi钢的耐蚀性11,193NO犷对闭塞区腐蚀的抑制作用11.225交变电场对钝化膜性质的影响11,319在Nacl溶液中的缝隙腐蚀11,353在强酸性含Cl一介质中的孔蚀11,393载波钝化及其后处…     

自身电偶腐蚀

1　起因于钝化金属的局部失钝当两种不同的金属相互电接触并且周围有导电介质存在而构成电流回路时就会发生电偶腐蚀 ,也称伽伐尼腐蚀。这种导电介质常常是液体 ,例如水溶液。两种金属构成电偶 ,由电偶中电位较正的金属提供极化电流 ,把电位较负的金属极化到较正的电位 ,使其腐蚀速度变大。这一过程跟发生在普通电池中的过程在本质上完全一样 ,只不过在电池中电流被迫通过外部负载 ,于是得到有用功。通常 ,电偶腐蚀几乎总是与两种不同的金属或合金相联系 ,例如碳钢和黄铜。然而 ,也有在同一金属或合金上建立起电偶电池的 ,即所谓的“自身电…     

防腐包装文摘

对于金属腐蚀速度理论,解说了以下内容的腐蚀电化学理论,阳极、阴极反应电位——电流曲线的测定,均一的腐蚀速度理论,金属的钝化、氧浓差局部电池腐蚀理论、表面腐蚀生成物薄膜     

金属的交流电腐蚀

当金属构件与周围环境(介质)作用而发生腐蚀时,若有交流电通过金属构件和腐蚀介质,会对金属腐蚀过程产生重要影响,这个过程称为交流电腐蚀。交流电腐蚀与直流电腐蚀不同。直流电的流动方向是一直不变的,外界的直流电通过由金属、介质等组成的腐蚀电池时,若金属与电源阳极相接,则金属—直被溶解,若与阳极相接,则金属一直处于被保护状态。如果腐蚀电池与外界交流电源相接,金属上的外界电流大小和方向变化很快,如工频电流变化周期仅有0.02秒时间。这个外界交流电对金属腐蚀中的电化学反应、钝化膜生长与破坏均可能产生作用。因此,交流电腐蚀引起人们广泛的注意。     

电化学噪声技术检测核电环境材料的腐蚀损伤

探讨和解决了电化学噪声技术在核电环境材料腐蚀损伤检测应用的关键问题,建立了基于零阻电流（ZRA）检测的SCC电化学噪声测试体系。采用小面积的Pt或表面热喷涂陶瓷涂层的工作电极材料作为对电极,研制适用于核电现场检测的多种电化学传感器。运用Compact RIO模块化仪器和设计制作的基于ZRA电路的电化学噪声测试模块,实现电位一电流噪声的同步测量和采集。成功研制出便携式核电材料损伤检测系统。应用研制的测试系统和电化学传感器研究了高温高压和动态水环境304不锈钢的电化学噪声谱特征。并初步实现了在役核电站辅助车间不锈钢管道表面直接腐蚀检测和钢厂动力锅炉连续排污管的现场腐蚀检测,取得了比较满意的结果。     

Development of corrosion sensors for monitoring steel‐corroding agents in reinforced concrete structures

Corrosion sensors were devised to develop a system whereby the depth of chloride permeation from concrete surfaces can be monitored non‐destructively on a real‐time basis using such sensors embedded in cover concrete of reinforced concrete structures. The proposed corrosion sensors were subjected to accelerated corrosion in NaCl solutions, mortar specimens intrinsically containing chlorides, and mortar specimens impregnated with chloride solutions, while recording the changes in the resistance readings. The resistance of sensors increased as the degree of corrosion increased. The time to the first change in the resistance decreased and the corrosion degree and resistance increased as the chloride concentration increased and as the distance from mortar surfaces decreased. It was therefore confirmed that the corrosion sensors are capable of monitoring the depth of chloride permeation with sufficient accuracy.     

混凝土结构中钢筋腐蚀智能监测技术

对混凝土结构中钢筋腐蚀监测技术的研究成果进行了综述,同时指出传统监测手段的不足之处,并提出了智能监测技术的要求;着重分析了钢筋腐蚀监测光纤传感器和无线传感器的研究进展,并展望了混凝土结构中钢筋腐蚀智能监测技术的发展方向.     

Long-term Field Corrosion Monitoring in Supporting Structures of China Xiamen Xiangan Subsea Tunnel

Xiamen Xiangan Subsea Tunnel is the first undersea tunnel constructed in China.It has become the major undersea pathway connecting Xiamen Island and Xiangan District since its operation in 2010.The total length is 6.05 km with the undersea length of 4.2 km.In an effort to onsite-monitor reinforcement corrosion in concrete structures,the commercially available CorroWatch multiprobe sensors and ERE-20 reference electrodes were pre-embedded in the selected locations and positions of supporting structures during the tunnel constructions.The real-time data have been collected annually by onsite measurements for 6 years.In this paper,the feasibility of the onsite corrosion monitoring system and suitability of the measured parameters including corrosion current,potential and temperature are discussed based on the preliminary results.The measured typical cyclic-type variations in corrosion current and temperature with monitoring time might be related to the seasonal changes during the annual routine measurements.The widely scattered corrosion potentials that are fluctuated complicatedly reflected localized differences in the vicinity of rebar and concrete.These findings,along with the progressively ongoing research,will provide valuable information in structural durability for service life prediction of reinforced concrete structures exposed to marine environments.     

交流阻抗法在凝汽器黄铜管腐蚀研究中的应用

探讨交流阻抗法研究凝汽器黄铜管在循环冷却水系统中的腐蚀问题.采用热电厂实际使用的黄铜管制作管状传感器,利用交流阻抗法在同种材料三电极体系电解池中测量传感器的电化学阻抗谱,并与经典三电极体系电解池下的数值作比较.结果表明,实验室数据与现场测试数据基本吻合,交流阻抗法可以提供凝汽器黄铜管在循环冷却水系统中的年腐蚀速率和极化电阻,帮助现场工作人员及时了解凝汽器黄铜管的腐蚀状况.交流阻抗法可以有效地评定黄铜管的耐腐蚀性能,为现场腐蚀监测,进而指导生产提供了有益信息.     

Remote corrosion monitoring of the RC structures using the electrochemical wireless energy-harvesting sensors and networks

Essentially, the corrosion process of the steel bar in reinforcing concrete structures is a series of electrochemical reactions. Therefore, the released energy during these reactions provides the opportunities to identify the corrosion status and power the wireless corrosion monitoring sensors. Furthermore, the recognition of the corrosion status has been realized with active monitoring techniques (AMTs) and passive monitoring techniques (PMTs). Additionally, the sensor mote platform that harvests the corrosion energy has been designed for corrosion monitoring, and then how to network these sensors to remotely access the corrosion data has been discussed. The preliminary experiment has been conducted to validate the micro corrosion energy.     

光纤金属腐蚀传感器研究及应用进展

光纤传感技术具有诸多传统的检测方法不具备的优点,如防电磁干扰、传感器体积小、重量轻,可以进行远距离探测等,近年来越来越多的应用于金属腐蚀监测领域。本文综述了探测透射光强型、光纤光栅型、荧光光谱型等类型的光纤金属腐蚀传感器的工作原理、研究应用现状及发展趋势。     

Listen to corrosion at work — A newly developed versatile corrosion monitoring tool ready for plant application

The basic principle of a new approach of electrochemical noise (ECN) diagnostics, the Coulombs counting method, is outlined, and the wide range of application as an online‐monitoring tool in technical corrosion systems is exemplified. It is shown that corrosion monitoring can be achieved with ECN sensors as simple as monitoring temperatures. A special feature of this method is that corrosion in crevices or under deposits can be investigated under real‐time conditions. This allows to monitor the efficiency of mitigation measures, e.g. application of corrosion inhibitors, under crevice corrosion conditions. The new ECN diagnostic approach listens to the message of corroding systems and translates it into technically relevant information.     

Comparative investigation on copper atmospheric corrosion by electrochemical impedance and electrical resistance sensors

Electrochemical impedance (EIS) and thin electrical resistance (ER) sensors were invented for atmospheric corrosion measurement of copper (Cu) during cyclic wetting–drying/high–low temperature tests and field exposure tests. Three-month field exposure results showed that average corrosion rate of Cu measured by ER sensor was well in accordance with that by weight loss method. During cyclic wetting–drying test, EIS was proven to reflect sensitively time of wetting and drying on the surface of sensor. Although corrosion rate obtained from EIS had a similar tendency to that obtained from ER sensors, the former was more dependent on environmental humidity than the latter. When relative humidity was low than 60%, corrosion rate of Cu measured by EIS was much lower than that by weight loss method, mainly attributing to the fact that impedance sensor failed to detect corrosion current of interlaced Cu electrodes due to the breakdown of conductive passage composed of absorbed thin liquid film under low humidity condition. Promisingly, ER sensor was proven to be more suitable for atmospheric corrosion monitoring than electrochemical techniques because it could sensitively monitor thickness loss of Cu foil according to the Ohmic law, no matter how dry or wet the sensor surface is.     

Experimental methods designed for measuring corrosion in highly resistive and inhomogeneous media

Corrosion measurement in highly resistive and inhomogeneous media can be very challenging due to practical difficulties in setting up and maintaining testing cells and sensors, problems associated with IR potential drops and nonuniform polarisation current distribution, and limitations associated with localised corrosion monitoring and detection. Many technological innovations have been made over the past decade to address these issues with reports scattered throughout the literature. This paper provides an overview of innovative experimental methods designed for corrosion testing and monitoring in highly-resistive and inhomogeneous media, with particular focus on localised corrosion measurement using electrode array and electrochemical noise techniques.