Corrosion longevity of gas turbine blades protective coatings

Results obtained from long-term studies conducted at the NPO Central Boiler-Turbine Institute on determining corrosion longevity of gas turbine blade protective coatings applied using different methods are presented. It is found how the base and alloying elements of coatings, the ceramic layer thickness, and the corrosion resistance level of undercoat alloy influence the longevity of coatings.     

The effect of the alloying elements of a CoNiCrAlY system on the corrosion resistance of alloys for protective coatings of gas turbine blades

Results from testing for resistance to sulfide-oxide corrosion of model alloys used to make possible CoNiCrAlY system-based protective coatings are presented. The effect exerted by Ni, Cr, Al, and Y on the corrosion resistance of these coatings at different temperatures is determined, and equations for calculating the chromium equivalents of these coatings are obtained.     

Regularities of degradation of thermal barrier coatings of the MCrAlY/ZrO2 system under sulfide-oxide corrosion conditions

The results from investigation of the service life of thermal barrier coatings under the conditions of sulfide-oxide corrosion at 800, 850, and 900°C are considered. The effect of the ceramic layer thickness, the aluminum and chromium concentration in the metallic layer, and the formation of the oxide film in the boundary region on degradation and corrosion longevity of coatings is determined.     

滨海电厂控制系统电器设备的大气腐蚀与防护

滨海地区的大气腐蚀性较强,极大地影响了滨海电厂集散控制系统(distributed control system,DCS)的稳定性和使用寿命.为此,研究了滨海地区的大气腐蚀因素,分析滨海电厂DCS各种电器设备的腐蚀原因及机理,并在此基础上给出了合理的腐蚀防护措施,主要有镀层、喷涂防护漆、添加缓蚀剂以及电化学保护等.     

Corrosion and Microstructure Behaviour of Steel Strand Used in Bridges

Abstract

The corrosion and microstructure behavior features, such as steel strand corrosion and corrosive wear of the as-prepared composite coatings and substrates were investigated. It is found that the experimental pitting depth followed a normal distribution and both the location and scale parameters increased with the corrosion degree. The fatigue test results indicated that corrosion could cause a significant decrease in the fatigue life of corroded steel wires. The substrate exhibited corrosion-accelerating wear, while the coatings exhibited wear accelerating corrosion. A method based on 3D measurements and AFGROW software was proposed to predict the remaining fatigue life of corroded steel wires. The predicted fatigue lives agreed well with the test results.     

菏泽发电厂420 t/h煤粉锅炉水冷壁高温硫腐蚀分析及防治对策

菏泽电厂 420煤粉锅炉水冷壁发生的高温腐蚀t/h ,为硫酸盐、硫化铁、硫化氢 3种腐蚀并存,属于高温硫腐蚀类型。分析其原因,主要是入炉煤的含硫量太高,K、Na等致腐物质含量较高;双通道燃烧器的空气动力工况不良,在水冷壁附近存在较高的硫化氢等腐蚀气体等。采取了控制入炉煤质量,改善配风,合理组织燃烧,在水冷壁腐蚀区域喷涂铝基防腐层,在水冷壁上预留缝隙喷口,改善贴壁气氛等措施。     

火力发电厂热力设备腐蚀与对策

随着火力发电厂大容量高参数机组的投运,防止腐蚀及结垢的措施也应加强。通过对腐蚀及结垢的原因分析,提出加强水汽监督保证水汽质量的高度纯净,定期进行化学清洗是防止设备腐蚀的有效措施。     

输电铁塔腐蚀防护全寿命周期成本

对山东电网输电铁塔的腐蚀防护状况进行了调查分析,获得了首次防腐蚀维护时间、维护间隔、维护费用等数据;对热浸镀锌、热喷涂锌铝镁稀土合金的耐蚀性能及成本进行了调查分析。依据调查结果及前期试验结果,对输电铁塔热浸镀锌、热喷涂锌铝镁稀土合金2种初始防护方法进行了全寿命周期（40年）腐蚀防护总成本计算分析,结果表明：较小塔型热浸镀总成本低,而较大塔型及钢管塔热喷涂方法总成本更低。     

超疏水绝缘涂层制备与防冰、防污研究现状

输电线路的覆冰灾害是电力系统最严重的威胁之一。超疏水绝缘涂层具有强憎水性和低表面能,因而具有提高输电线路防覆冰与防污性能的潜力。对超疏水绝缘涂层的制备方法及其在电力系统中的应用研究现状进行概述,介绍超疏水绝缘涂层的电绝缘性、化学稳定性、机械稳定性等基本性能,对比分析超疏水绝缘涂层与普通憎水性绝缘涂层的防覆冰与防污性能,阐明超疏水绝缘涂层在延缓绝缘子覆冰方面的机理。此外,对超疏水绝缘涂层在耐腐蚀等领域的应用研究现状也进行了介绍。提出在未来输电线路超疏水绝缘涂层的研究中,应重点关注制备方法的经济性、涂层表面的长效性以及防污闪机理等方面的关键问题,提升涂层的综合性能。     

PECVD法沉积类金刚石薄膜的耐腐蚀性能研究

金属材料在实际生活中应用广泛,但其易被摩擦磨损及易被腐蚀的特点成为其广泛应用中的主要障碍。本文介绍利用类金刚石（Diamond-like Carbon,DLC）的高硬度、低摩擦系数、高耐磨性及高化学稳定性等特点,采用等离子体增强化学气相沉积的方法,以C2H2为碳源、Ar为辅助气体在金属表面沉积DLC薄膜来提高金属的耐磨...     

Corrosion performance of lamellae nanostructured fluorinated organic coating applied on steel

This work investigates a new organic coating for corrosion protection. This coating is a Poly(n-butyl acrylate-b-trifluoroethyl methacrylate) diblock copolymer elaborated by Controlled Radical Polymerization and then deposited on steel. Several parameters were taken into account to evaluate their influence on corrosion protection properties: the PBA molar mass, the solvent type (THF or Dichloromethane), the thickness of coatings and the nature of the nanostructuration (lamellae or sphere). The thickness of the films was measured between 45 and 265 μm by optical microscopy and by gravimetric difference measurements. Atomic Force Microscopy (AFM) observations show a homogeneous surface of the coating with a nanostructured lamellar structure. The electrochemical behaviour was studied by Electrochemical Impedance Spectroscopy (EIS) in a sodium sulphate solution. The better corrosion resistance was obtained for coating thickness higher than 265 μm. On the other hand, poor results were obtained using a PBA high molar mass and dichloromethane as solvent.     

切圆燃烧锅炉水冷壁高温腐蚀和结渣部位研究

对切圆燃烧锅炉结渣及高温腐蚀的发生部位及其规律进行了研究,结果表明,通过设计合理的假想切圆直径,尽可能将卫燃带布置在背火侧水冷壁上,以及在易发生高温腐蚀区域喷涂防腐材料等,可有效防止或减缓水冷壁的严重结渣或高温腐蚀。     

锅炉低温再热器烟侧管壁腐蚀原因分析

通过对锅炉运行和停备用期间低温再热器管受热面烟侧表面腐蚀形貌、腐蚀特征、外壁腐蚀产物实验研究结果的分析，并结合其腐蚀的机理。判断锅炉低温再热器烟侧管壁出现大范围点腐蚀坑的原因，与停炉保护不当导致的氧腐蚀有关的结论。最后根据低温再热器表面腐蚀检查状况，提出保障其长期安全运行的措施。     

FeCrAl和高镍铬合金涂层的抗高温腐蚀性能研究

根据火电厂锅炉的运行工况,采用高温涂盐试验对高速电弧喷涂技术制备的FeCrAl涂层和高镍铬合金涂层进行耐高温腐蚀性能试验,并通过金相显微镜、扫描电镜、X射线衍射、能谱分析等手段对涂层在熔盐环境下腐蚀前、后的性能和腐蚀机理进行细致研究。结果表明,FeCrAl和高镍铬合金涂层均具有良好的抗高温腐蚀性能,是一种经济有效的火电厂锅炉水冷壁防护涂层。     

火电厂锅炉高温硫腐蚀机理及解决方法

高温硫腐蚀是高硫分燃煤锅炉普遍存在的问题,它会引起锅炉受热面泄漏。以华能珞璜电厂360 MW机组为对象,简述了各种高温硫腐蚀的解决方法,其中金属喷涂是一种行之有效的措施。     

锅炉受热面管的复合涂层防护的研究

针对燃煤电站锅炉因受热面管子磨蚀严重,导致泄漏、爆管等而被迫停炉检修的情况,开展了受热面管复合涂层防护技术的研究。根据受热面管的形状、工况条件和使用环境,对电弧喷涂工艺进行了探讨,并对若干适用于锅炉抗高温磨蚀的喷涂丝材所制成涂层的微观组织结构、硬度、涂层结合性能、耐冲蚀磨损性能和抗高温腐蚀性能等进行了深入的分析。结论是以超音速电弧喷涂NiAl丝材作为结合底层,金属-陶瓷材料或高铬材料作为功能层并辅以高温封孔的复合涂层的制备技术,可以同时兼顾可靠性和经济性。     

聚苯胺改性钢在模拟PEMFC环境下的电化学行为

利用电化学方法沉积纳米导电聚苯胺膜对质子交换膜燃料电池(PEMFC)用薄层金属双极板改性,并对改性双极板在模拟PEMFC阳极环境下的电化学性能进行了测试.结果表明,纳米聚苯胺膜层能使1Cr18Ni9Ti不锈钢在模拟腐蚀液中的腐蚀电位由-350mV提高到250mV.在模拟阳极操作电位下,经10h恒电位极化没有观察到膜层的降解和脱落.纳米导电聚苯胺膜层能显著提高不锈钢在模拟电池环境下的耐蚀性而不影响其导电性,进一步提高导电聚合物涂层性能和评价其长期效果还需进行深入的研究.     

Corrosion Control in Electric Power Systems

The electrochemical mechanism of aqueous corrosion is outlined, and it is demonstrated that the process depends on a complex interaction between the material and its environment given the particular circumstances of exposure. Failure to recognize the full implications of the environment or the circumstances will often lead to unexpected corrosion failure. The technique for controlling corrosion are subdivided into material selection, coatings, electrical insulation, cathodic protection, etc. Each technique is described and explained. The need to apply a considered corrosion control package, rather than the use of a single technique, is stressed.     

衡水发电厂循环水管道腐蚀原因分析

针对衡水发电厂循环水管道腐蚀问题，通过在不同工况下的对比试验，分析其原因并提出了防止腐蚀的建议。     

盐碱环境中变电站接地体材料的腐蚀行为研究

文中通过实验室埋片腐蚀失重试验、自腐蚀电位和腐蚀速率的测试,研究了3种变电站地网材料（镀锌钢、铜、导电防腐涂料）在沿海盐碱土壤（原状土和回填土）中的腐蚀行为和规律.研究结果表明,在盐碱土壤中镀锌层呈现高的腐蚀活性,对钢不具有保护作用,纳米碳导电防腐涂料对钢也没有明显的保护效果,而铜在回填土中的腐蚀速率约仅有镀锌钢的1％.研究成果为变电站接地材料的选择提供了技术支撑.