3PE防腐蚀层联合阴极保护对管道的保护效果

采用阴极保护联合3PE防腐蚀层的方法对埋地钢质管道进行了防护。试验模拟了管道3PE防腐蚀层底漆存在、金属基体暴露、金属暴露孔处未与土壤介质接触及与土壤介质完全接触的不同情况,探讨了阴极电流与通电电位之间的关系,研究了通/断电位的负移对试样3PE防腐蚀蚀层阴极剥离的影响。结果表明,试样阴极保护电流的变化与管道3PE防腐蚀层的缺陷存在、土壤接触方式、通电电位密切相关。通/断电电位正于-0.85V(CSE)时,难以阻止试样发生腐蚀,通/断电位过度负移将造成3PE防腐蚀层的阴极剥离,使3PE防腐蚀层提前失效。     

耐火粉料对金属型涂料性能的影响

研究了硅藻土、莫来石、滑石粉、白刚玉4种不同耐火粉料对金属型涂料悬浮率、强度、条件粘度、发气量、触变性的影响。实验结果表明:硅藻土是影响涂料悬浮率、发气量和强度的最显著因素;莫来石可以有效提高涂料的悬浮率及粘度;滑石粉是影响涂料条件粘度的最显著因素;不同的粉料组成对涂料的流体形态及条件粘度影响较大。     

用直流电位梯度法测量埋地管道防护层缺陷位置的模拟试验

介绍了埋地管道防护层缺陷电位梯度检测技术。用盐溶液、蒸馏水和自来水的混合液模拟土壤介质,通过改变管道防护层缺陷大小,改变环境电阻率和保护电流,试验证明了电位梯度检测技术能够比较准确地检测出管道防腐层缺陷的位置,并得到了管道埋深和地表电位梯度的关系。     

地下管道防护层缺陷检测技术研究与应用

埋地钢制管道腐蚀检测及防护是相关行业工作中的重要内容.本文介绍了国内外管道防腐层缺陷检测的几种检测方法,包括标准管地电位法、近间距电位法、电流梯度法、直流电位梯度法等,分析了各种管道检测技术的原理和优缺点.重点说明了直流电位梯度法在确定防腐层缺陷位置方面的优越性.     

Improving the Anticorrosion Characteristics of Polymer Coatings in the Case of Their Modification with Compositions Based on Organosilanes

Protection of Metals and Physical Chemistry of Surfaces - The effect of a series of organosilanes and their mixtures with corrosion inhibitors on the anticorrosion properties of polymer and paint...     

一种埋地管道剥离涂层下金属腐蚀电化学试验装置

针对防腐蚀层剥离管道在土壤环境中的腐蚀问题,在总结现有国内外相关研究试验装置与研究方法的基础上,设计组装了一套新的电化学试验装置。该装置在具有制造简单、方便、可重复试验的同时,能够较好地模拟埋地管道涂层破损、剥离状态下金属基体的腐蚀环境。测试性试验结果表明,该试验装置便于电化学阻抗谱、极化曲线等电化学测量信号的测试。     

玻璃鳞片对环氧涂料抗阴极剥离性能的影响

测试了玻璃鳞片的添加对环氧涂料抗阴极剥离性能的影响。发现,添加玻璃鳞片的环氧涂料具有较好的抗阴极剥离性能。对其机理进行了一定的探讨。     

聚合物基复合材料表面防护涂层的研究现状与展望

聚合物基复合材料相比金属等传统材料,其耐高温性能、抗固体颗粒冲蚀磨损性能等不足,导致聚合物基复合材料在高新技术领域、高温磨损等复杂工况中的应用受到严重制约.研究表明,在聚合物基复合材料表面制备功能性防护涂层,是一种有效提高或改变复合材料表面性能的途径.在介绍聚合物基复合材料基本性能特点的基础上,系统总结梳理了热喷涂、冷...     

有机涂层防护性能的电化学研究进展

曝晒、盐雾、浸泡、干湿循环、老化等传统的有机涂层防护性能研究方法,因测试周期长,测试结果多为定性分析,不能使涂层材料进行快速检验而投入评估使用.正是由于传统测试方法存在许多局限性,故综述了稳态电化学测试方法和暂态电化学测试方法这两种新技术在有机涂层防护性能中的应用与进展.介绍了动电位极化曲线法、极化电阻法等稳态电化学测试方法,这类方法主要反映涂层的极化电阻和腐蚀速度,并且方法简单,可直接分析实验数据,被广泛应用于有机涂层的失效分析中.而暂态电化学测试方法主要包括电化学阻抗法(EIS)、局部阻抗法(LEIS)、扫描Kelvin探针法(SKP)及电化学噪声(EN)等,主要用于研究涂层防护机制和局部缺陷.目前,在有机涂层防护性能和机理研究中,应用最多的是电化学交流阻抗法.丝束电极法(WBE)、扫描电化学显微镜(SECM)以及原子力显微镜(AFM)用于研究金属/涂层界面物理化学变化规律.阐述了上述方法在涂层防护研究中的应用成果及其优势和不足,指出对于深层次的涂层防护研究,需要应用多种测试手段,从不同的角度和方面综合分析,全面评估涂层的使用寿命.     

Effect of Coil Current on the Properties of Hydrogenated DLC Coatings Fabricated by Filtered Cathodic Vacuum Arc Technique

We successfully prepared hydrogenated DLC (a-C:H) with a thickness higher than 25 μm on stainless steel using a filtered cathode vacuum arc (FCVA) technique. The structural and mechanical properties of DLC were systematically analyzed using different methods such as x-ray photoelectron spectroscopy, Raman spectroscopy, scanning electron microscopy, Vickers hardness, nanohardness, and friction and wear tests. The effect of coil current on the arc voltage, ion current, and mechanical properties of resultant films was systematically investigated. The novelty of this study is the fabrication of DLC with Vickers hardness higher than 1500 HV, in the meanwhile with the thickness higher than 30 μm through varying the coil current with FCVA technique. The results indicated that the ion current, deposition rate, friction coefficient, and Vickers hardness of DLC were significantly affected by the magnetic field inside the filtered duct.     

Parametric Study of Metal/Polymer Multilayer Coatings for Temperature Wrinkling Prediction

This article presents an analytic model for the prediction of wrinkling occurring in metal/polymer coatings under particular conditions. Owing to different thermal expansion coefficients (TECs) of the substrate and the different coating layers, temperature variation can induce a compressive stress in the coating. The wrinkling is the material response to the instability caused by this compressive stress. In this study, a reference case was selected: a 0.27-mm-thick steel sheet with a 5-μm-thick polymer layer and, on top of it, a thin aluminum film of 50 nm in thickness. For this reference case, it was observed and predicted by the model that an increase in temperature yielded to the wrinkling of the thin aluminum film. The geometry of the multilayer coating and the properties of the constituent materials are factors able to promote or prevent the wrinkle. To better understand and predict their effects, a sensitivity analysis was carried out with the proposed analytic model. A special attention was devoted to the temperature when wrinkling occurs. The key parameters having a significant influence on the wrinkling temperature were identified. It is concluded that the elastic modulus of the thin aluminum film and that of the polymer, the TEC of the thin film, and the initial stress induced during the processing of the multilayer system all had a significant influence on the wrinkling temperature.     

EIS Studies of Protective Polymer Coatings on Low-Carbon Steel in Sulfuric Acid

Protection of Metals and Physical Chemistry of Surfaces - Abstract—The electrochemical properties of protective epoxy polymer coatings with different designs are studied with electrochemical...     

飞机金属结构防护层在多因素耦合作用下损伤行为与失效预测模型

模拟飞机中央翼、平尾大轴等部位的基体及其防护层,在紫外、热冲击、低温疲劳、盐雾多因素耦合作用下开展试验,对不同试样的损伤形貌和电化学参量随着试验周期的演变规律进行统计分析。结果表明:损伤主要为颜色变化和鼓泡,损伤形貌的变化与低频下阻抗模值存在一定的对应关系;给出不同失效阶段低频电化学阻抗模值范围以及对应的失效形貌。对国内外防护层失效预测模型进行调研分析,防护层失效预测模型主要有阻抗模值数据处理法、老化动力学模型。分析现有模型存在的局限性,在此基础上,对老化动力学模型进行改进,提出全频率老化动力学模型,并新建立神经元网络失效预测模型。利用铝合金、钢及其防护层在不同实验条件下的实验结果对各模型的预测结果进行比对分析。     

航空航天用金属表面热防护涂层的研究进展

高温合金材料凭借其优异的综合性能而广泛应用于航空航天领域热端部件.近年来,随着航空航天技术的不断发展,飞行器的热端部件正逐渐面临着更为严峻和复杂的服役环境,因此对高温合金的耐高温、抗氧化等使用性能提出了更高的要求.表面涂层技术由于具有约束条件少、可设计性强、技术类型和材料的选择空间大、经济环保等优点,成为目前最常用的热...     

TC4钛合金表面超音速火焰喷涂防护涂层及其摩擦学性能研究

目的 改善钛合金零部件之间因相对滑动造成的磨损,提升钛合金零部件的使用寿命。方法 采用超音速火焰喷涂(HVOF)方法在TC4钛合金表面上制备Cr₃C₂-NiCr、Ni50和Ni Cr涂层。采用扫描电子显微镜(SEM)、显微硬度计等分析涂层的显微结构及力学性能,采用多功能摩擦磨损试验机及白光共焦三维形貌仪测试和分析不同涂层与TC4钛合金在干摩擦条件下的摩擦学性能。结果 Ni50和NiCr涂层的硬度分别为680HV0.3和438HV0.3,低于Cr₃C₂-NiCr涂层硬度1 120HV0.3。在高载荷作用下,由于Ni50和NiCr涂层的硬度较低,导致其颗粒界面出现裂纹,断裂韧性测试表现低于Cr₃C₂-NiCr涂层。3种涂层的摩擦系数及波动均大于TC4钛合金基材。Cr₃C₂-NiCr涂层对TC4的切削和NiCr涂层对TC4的黏着导致了TC4对磨副的严重磨损。中等硬度的Ni50涂层对TC4的切削和黏着作用分别弱于Cr     

Model Investigation of the Peculiarities of the Corrosion and Cathodic Protection of Steel in the Insulation Defects on Underground Steel Pipelines

The new data of model investigations on cathodic passivation, nature of galvanic macrocells, and the dimensional effects in the defects of insulation on underground pipelines are analyzed. Partially revising some conventional concepts concerning the mechanism of the corrosion and cathodic protection of steel in soils is advisable.     

Properties of Induction Plasma Sprayed Iron Based Nanostructured Alloy Coatings for Metal Based Thermal Barrier Coatings

Metal-based thermal barrier coatings (MBTBCs) have been produced using high frequency induction plasma spraying (IPS) of iron-based nanostructured alloy powders. The study of MBTBCs has been initiated to challenge issues associated with current TBC materials such as difficult prediction of their “in-service” lifetime. Reliability of TBCs is an important aspect besides the economical consideration. Therefore, the study of MBTBCs, which should posses higher toughness than the current TBC materials, has been initiated to challenge the mechanical problems of ceramic-based TBCs (CBTBCs) to create a new generation of TBCs. The thermal diffusivity (TD) (α) properties of the MBTBCs were measured using a laser flash method, and density (ρ) and specific heat (C _p) of the MBTBCs were also measured for their thermal conductivity (k) calculation (k = αρ C _p).     

The Effect of a Metal Surface on the Elasticity of Polymer Films

Protection of Metals and Physical Chemistry of Surfaces - The influence of the nature of the surface on the elastic properties of acrylic polymers with different glass-transition temperatures...     

海泡石对消失模涂料性能的影响

以高铝粉为耐火骨料,以海泡石和CMC作为悬浮剂,研究了一种适用球墨铸铁铸件的水基消失模涂料,分析了各原料加入量对涂料性能的影响。结果显示:增加海泡石的量能提升涂料悬浮性和涂层强度;磷酸二氢铝能提高涂层强度,但会降低涂料透气性;珍珠岩能提高涂料透气性。当海泡石的量为10%,磷酸二氢铝为4%,珍珠岩为12%时,各原料能有最佳的交互作用。