舟山某码头钢管桩牺牲阳极阴极保护系统检测

舟山某码头钢管桩采取牺牲阳极阴极保护已10余年。通过检测阳极的表面形貌,计算阳极使用寿命,测量保护电位和检查钢管桩腐蚀状况,对牺牲阳极保护效果进行了评价和分析。结果表明,10年间钢管桩受到了充分有效的保护,阳极剩余寿命在10年以上,实际使用寿命将大于设计寿命。     

铁基牺牲阳极对17-4PH不锈钢的阴极保护

采用两种铁基牺牲阳极材料 (20CrMo和40CrMo) 对17-4PH不锈钢进行阴极保护,通过恒电流实验和自放电实验评估这两种牺牲阳极的保护效果,并用扫描电镜 (SEM) 和能谱 (EDS) 分析17-4PH阴极实验后的表面形态和元素成分。结果表明：两种牺牲阳极对17-4PH不锈钢均有500 mV左右的驱动电位。20CrMo牺牲阳极具有比40CrMo更负的工作电位、更大的电流效率,20CrMo牺牲阳极表面均匀腐蚀。经过20CrMo阳极保护的17-4PH阴极表面形成的氧化产物含量更少。20CrMo对17-4PH不锈钢的保护效果更好。     

Cathodic protection of steel in concrete using magnesium alloy anode

Corrosion of steel embedded in concrete structures and bridges is prevented using cathodic protection. Majority of the structures protected employ impressed current system. Use of sacrificial system for the protection of steel in concrete is not as widely employed. The use of magnesium anodes for the above purpose is very limited. This study has been carried out with a view to analyse the use of magnesium alloy anode for the cathodic protection of steel embedded in concrete.Magnesium alloy anode, designed for three years life, was installed at the center of reinforced concrete slab, containing 3.5% sodium chloride with respect to weight of cement, for cathodic protection. Potential of the embedded steel and the current flowing between the anode and the steel were monitored, plotted and analyzed. Chloride concentration of concrete at different locations, for different timings, were also determined and analyzed.The magnesium anode was found to shift the potential of the steel to more negative potentials initially, at all distances and later towards less negative potentials. The chloride concentration was found to decrease at all the locations with increase in time. The mechanism of cathodic protection with the sacrificial anode could be correlated to the removal of corrosive ions such as chloride from the vicinity of steel.     

钢质石油储罐罐底外壁牺牲阳极阴极保护

本文对钢质石油储罐的腐蚀机理、因素进行了分析,介绍了牺牲阳极阴极保护的原理,对1座10000m3的钢质石油储罐罐底外壁进行了牺牲阳极阴极保护设计,并对其保护效果进行了检验。结果显示该储罐实施牺牲阳极保护后,牺牲阳极保持较低的工作电位,使罐底外壁得到相应保护,达到了设计技术要求,有效减缓罐底外壁的腐蚀速率。     

Influence of Mg and Ti on the microstructure and electrochemical performance of aluminum alloy sacrificial anodes

The experiments focused on the influence of magnesium and titanium as additional alloying elements on the microstructure and electro-chemical behavior of Al-Zn-In sacrificial anodes. The electrochemical behavior of the aluminum sacrificial anode with 3 wt.% sodium chloride solution was studied by electrochemical impedance spectroscopy (EIS) tests. It was found that a microstructure with few precipitates and refined grains could be achieved by adding 1 wt.% Mg and 0.05 wt.% Ti to the Al-Zn-In alloy,resulting...     

Bi含量对Al-Zn-Ga-Si-Bi合金电化学性能和腐蚀形貌影响

通过在Al-Zn-Ga-Si低电位牺牲阳极材料中添加Bi来改善阳极的性能，以不同Bi含量制备了5种牺牲阳极材料。通过电化学性能测试、极化曲线以及电化学阻抗谱测试来分析Bi对阳极电化学性能的影响；采用三维视频和宏观表征来分析Bi对阳极腐蚀形貌的影响。结果表明，添加适量Bi可以有效破坏铝合金阳极表面的氧化膜，提高阳极活化性能，并减少晶界腐蚀的作用，改善阳极的溶解形貌，但Bi含量过高时反而降低阳极的均匀活化性能，当Bi含量为0.05%(质量分数) 时阳极综合性能良好，可用作高强钢的阴极保护。     

Effect of Zn/Mg ratio on cathodic protection of carbon steel using Al−Zn−Mg sacrificial anodes

Al−Zn−Mg alloys with different Zn/Mg mass ratios were evaluated as sacrificial anodes for cathodic protection of carbon steel in 3.5 wt.% NaCl solution. The anodes were fabricated from pure Al, Zn and Mg metals using casting technique. Optical microscopy, SEM−EDS, XRD and electrochemical techniques were used. The results indicated that with decreasing Zn/Mg mass ratio, the grain size of α(Al) and the particle size of the precipitates decreased while the volume fraction of the precipitates increased. The anode with Zn/Mg mass ratio >4.0 exhibited the lowest corrosion rate, while the anode with Zn/Mg mass ratio <0.62 gave the highest corrosion rate and provided the highest cathodic protection efficiency for carbon steel (AISI 1018). Furthermore, the results showed that the anode with Zn/Mg mass ratio <0.62 exhibited a porous corrosion product compared to the other anodes.     

南海1 200 m深海环境Al-Zn-In合金阳极电化学性能研究

目的 研究对比了3种不同配方Al-Zn-In合金阳极在南海环境条件下的腐蚀形貌及电化学容量、电化学效率等性能参数,为深海工程装备的阴极防护设计提供可靠的参考依据。方法 通过在我国南海1200m深海试验架上搭载阳极阴极保护测试装置及数据采集、存储系统,采用自放电测试（Free Running Test,FRT）试验方法研究了阳极在110 d长周期条件下的电化学性能,采用超景深三维显微镜对其表面腐蚀形貌进行了观测。结果 1#—3#阳极下水后工作电位均快速活化,整个试验阶段,平均工作电位分别为-1.029、-1.033、-1.098 V(Ag/AgCl/海水);电化学效率分别为81.62%、78.02%、87.90%。仅自主设计的3#配方阳极的开路电位和电化学效率达到了UNE-EN 12496-2013阴极保护设计标准的要求。结论 与模拟深海环境下的恒电流测试（Galvanostatic Test,GST）短期试验（4 d）结果相比,同一配方阳极在深海110 d长周期FRT测试条件下的电化学效率分别降低15.13%,18.87%和8.14%。长周期FRT试验更接近实际阳极服役状态,可为深海阴...     

交流电干扰对镁合金AZ41牺牲阳极电化学性能的影响

在模拟填包料环境的硫酸钙－氢氧化镁饱和溶液中,在ＡＺ４１镁合金牺牲阳极直流放电的同时引入交流电干扰,试验发现,引入交流电干扰时采用不同形状的辅助电极,电场分布情况不同,放电试验后镁阳极形貌明显不同,镁阳极工作电位等随着交流电干扰的增强面明显正移,有时甚至可能正于铁人开路电位,出现所谓的“极性逆转”现象。从硫酸钠＋铁氰化钾＿亚铁氰化钾溶液中测试的极化曲线来看,镁阳极上的腐蚀产物具有ｎ－型半导全的导电     

城镇燃气埋地钢质管道牺牲阳极阴极保护的设计

在明确了阴极保护的管道条件前提下,文章简述了埋地钢制管道牺牲阳极阴极保护基本原理,确定了应采用的阳极材料;给出了规范要求和设计参数、以及镁阳极接地电阻的简化计算公式;明确了不宜使用钢套管及对水泥套管内管道采取的保护措施;给出了阳极地床填包料的组分。     

变电站接地网的防腐方法研究

利用埋片失重法及电化学法测定接地网试片的腐蚀速率,对比分析了缓蚀剂、牺牲阳极阴极保护法及缓蚀剂-牺牲阳极阴极保护联合保护3种方法的优缺点。结果表明：分别采用1%钼酸钠、2%六偏磷酸钠和4%硅酸钠作为缓蚀剂,Q235钢接地网在土壤中的缓蚀效果均较好,接地网试片的腐蚀速率均减小至0.1200 mm/a,保护度能达到约70%;采用六偏磷酸钠+钼酸钠的复配缓蚀剂,Q235钢的腐蚀速率从0.4667 mm/a减小至0.0873 mm/a,保护度达到81.3%;采用镁牺牲阳极阴极保护技术,Q235钢的腐蚀速率从0.2671 mm/a 减小至0.0639 mm/a,保护度为76.1%;采用复配缓蚀剂-牺牲阳极法联合保护,Q235钢的腐蚀速率从0.3342 mm/a减小至0.0260 mm/a,保护度可达92.2%。     

车辆阴极保护效果测试与数值模拟

某型车辆长期处于高温、高湿、高盐雾和高日照的恶劣海洋环境中,通常采用牺牲阳极加涂层的方法保证车辆整体防腐蚀性能。对某型车辆牺牲阳极的保护效果进行了实车测试,并根据实测结果,提出了新的牺牲阳极保护方案,采用阴极保护优化软件Beasy对设计方案进行了数值模拟,为车辆腐蚀防护的信息化奠定了基础。     

Al-Zn-In-Si牺牲阳极在模拟海水及海泥环境中的电化学性能

目的 分析A13型Al-Zn-In-Si牺牲阳极在海水、海泥中的电化学性能.方法 采用恒电流极化进行4 d的加速实验,使用电化学阻抗谱(EIS)分析电化学腐蚀过程,通过扫描电子显微镜(SEM)、能谱分析(EDS)及三维超景深显微镜观察分析腐蚀形貌及表面化学成分,对比研究了Al-Zn-In-Si牺牲阳极在模拟海水和海泥环境下的腐蚀形貌、电化学性能.结果 在模拟海水和海泥环境中,尽管Al-Zn-In-Si牺牲阳极都满足DNVGL-RP-B401的要求,但在海泥环境中,其电化学效率仅为65.97％,远低于海水环境中的89.43％.牺牲阳极在海水环境中发生均匀腐蚀,而在海泥环境中却呈现严重的不均匀腐蚀现象,表面腐蚀坑为疏松多孔蜂窝状.结论 在海泥环境下,Al-Zn-In-Si牺牲阳极的腐蚀产物扩散困难,局部呈现腐蚀坑,自腐蚀速率高,导致电化学效率降低.溶解过程中,由于组织脱落,自身消耗增加,电化学容量降低,从而导致阳极在模拟海泥环境中的电化学性能低于海水环境,并揭示了阳极在模拟海水、海泥环境中的腐蚀机理.     

复合式牺牲阳极保护钢管桩的试验研究

本文报道在淡水环境中采用铝合金和镁合金复合式牺牲阳极对钢管桩进行阴极保护的可行性研究。分别检测了安装3组、4组或5组复合牺牲阳极后,钢管桩1天和7天的极化电位,评估了该方案的实际保护效果,确定了较为合理的镁合金与铝合金牺牲阳极的用量和比例。     

格形板桩码头牺牲阳极阴极保护效果检测与评估

对华南某港口5万吨级码头格形板桩牺牲阳极阴极保护效果的检测,详细介绍了检测的内容和方法.本工作采用修正的计算公式,准确计算了阳极的剩余寿命,分析了码头端部钢桩保护电位偏低的原因,并提出了一些维修建议.     

Korrosionsschaden durch Elementbildung – Fallbeispiel aus dem Stahlwasserbau

Corrosion damage by element formation – example from hydraulic steel structures Hydraulic steel structures with huge costs of investments generally are protected against corrosive deterioration. Usually the protection is guaranteed by application of a coating system based on polymeres. Additional application of priming coats can raise the efficiency. Research on a weir plant in this work however show, that even protection by a high performed coating system does not necessarely lead to a prevention of corrosion. Immediately there are no hints of a general denial of the applicated coating systems or any causal influence by the immersion medium (river water). The weir plant is constructed by high alloyed steel in combination with carbon steel, partly welded one to another. Thereby the premises of corrosion by galvanic elements are given: an electronic conductivity through the phase boundary of the different types of steel as well as an ionic conductivity by the immersion medium. Delaminations of the coating of the weir gate can be explained by that as well the anodic iron desolution (pitting corrosion) of the carbon steel. Even a renovation of the coating system by an inclusion of the alloyed steel did not stop the corrosion as a whole. An essential improvement of the protection efficiency finally was reached by the installation of a cathodic protection system with sacrificial anodes. With the help of Ohm's and Faraday's law the rate of iron desolution on the one side and the consumption of sacrificial material on the other side can be estimated.     

带状镁合金牺牲阳极在库鄯输油管线阴极保护中的应用

根据φ３７７埋地管道工业规模预备试验的初步结果，在土壤电阻率相当高的新疆库鄯输油管道工程中，分别依靠三组长１０００ｍ的带状镁合金牺牲阳极，在两个相邻的测试桩上以两根并联或四根并联的方式埋设使得长８１ｋｍ，１３１ｋｍ和１０７ｋｍ的三处φ６１０长输管段受到了有效的阴极保护。     

Kathodischer Korrosionsschutz von emaillierten Speicherwassererwärmern

Cathodic protection of enameled hot water tanks Cathodic corrosion protection of enameled hot water tanks has gained a degree of high reliability. According to market analysis the number of installations per year only for Germany amounts to more than 1/2 million tanks, while for Europe the total number of installations is in the region of some millions. Cathodic corrosion protection of commercial hot water tanks with galvanic anodes as well as impressed current anode systems is a technique that has been developed to some perfection, but still is with some possibilities for improvement. Subject of this article is to present the steps of development of cathodic corrosion protection of enameled hot water tanks by Mg sacrificial anodes as well as by impressed current anodes, to demonstrate the presently reached technical status and to show possible tendencies of its future development.     

Improving the efficiency of magnesium sacrificial anodes

To improve the efficiency of magnesium sacrificial anodes used in corrosion protection, the effect of microstructure was investigated. Efficiency was improved by controlling the amount of second-phase particles at grain boundaries, by producing a uniform distribution of impurities in the matrix, and by ensuring a micrometer-order cell size via cooling rate and heat treatment. After evaluation with the efficiency test, it was found that the efficiency values were quite good as compared with commercially available magnesium sacrificial anodes.     

Prevention of steel corrosion in concrete exposed to seawater with submerged sacrificial anodes

This paper presents the results of a study of the effectiveness of submerged sacrificial anodes in preventing the onset of pitting corrosion in the emerged part of marine piles. Experimental tests were carried out on reinforced concrete columns with steel embedded both in chloride free concrete and chloride contaminated concrete in order to compare the effects of sacrificial anodes on passive steel and on corroding steel. Results have shown, at least under the present testing conditions, that sacrificial anodes may be more effective in preventing corrosion initiation (i.e. in providing cathodic prevention) than in controlling ongoing pitting corrosion (i.e. in guaranteeing cathodic protection). Monitoring criteria for this type of prevention are also discussed.