北京故宫南三所琉璃瓦釉层腐蚀过程探究

主要利用XRD、SEM-EDS和拉曼光谱等方法对北京故宫南三所屋顶的部分绿色琉璃瓦釉面腐蚀过程进行分析,研究南三所琉璃瓦的釉层腐蚀变色过程与机理.通过分析发现,南三所绿色琉璃构件表面腐蚀物为硫酸铅、硫化铅和磷氯铅矿的混合物.铅离子会因水汽或酸雨从釉的骨架网络结构中溶出,并与大气粉尘与微生物腐蚀中的磷、硫、氯发生化学反应...     

碳钢在5mmol／L稀NaCl溶液中腐蚀行为研究

采用扫描电镜、Raman光谱、交流阻抗等方法研究了碳钢在5mmol／L NaCl溶液中的腐蚀行为。结果表明,金属表面将形成疏松锈层,其显著影响碳钢腐蚀过程。锈层由薄y-FeOOH层及厚Fe2O4层构成;其中Y—FeOOH易被还原而起氧化剂作用;Fe2O4层起大阴极作用,溶氧可直接在其表面还原。因此,锈层无法阻碍碳钢腐蚀,并且将加速其腐蚀过程;最终碳钢腐蚀速率由溶液中的氧极限扩散速度所决定。防腐措施心能抑制锈层的腐蚀促进作用。     

几种因素对带锈钢铁腐蚀行为的影响

锈层下碳钢的腐蚀是最主要的、持续时间最长的腐蚀形态,本文针对锈层钢铁腐蚀过程中的复杂性、锈层成份、介质的pH值和Cl-浓度和温度等因素对锈层下钢铁腐蚀行为的影响进行了讨论。     

超高耐蚀性氯化钾镀镉防护层的制备

介绍了一种具有超高耐蚀性的氯化钾镀镉防护层的制备工艺,包括在金属基体上从内到外依次制备氯化钾镀镉层、铬酸盐低铬彩色钝化层和羟基石墨烯封闭层.在钢铁件上制备的这种防护层在中性盐雾试验中20160 h无白锈生成,27000 h无红锈生成.这为解决金属在热带海洋环境中的强腐蚀问题提供了新的解决方案.     

实验室模拟老化及其对橡胶氧含量的影响

轮胎内橡胶构件的老化通常与氧化有关。在使用过程中，橡胶组件中的氧含量随时间而发生明显变化。利用加速老化条件，对橡胶样品进行实验室模拟老化的过程中，氧含量也有明显变化。近来，人们迫切需要深入认识轮胎带束层隔离胶的老化过程。本文旨在研究实验室老化条件对带束层隔离胶氧含量及相关的物理机械性能的影响。     

镀锌层在室内模拟大气环境中腐蚀行为及寿命评估

针对电力金具镀锌层在大气环境中腐蚀及寿命评估问题，通过KY-YW40室内腐蚀试验箱分别模拟工业、海洋腐蚀环境，采用SEM、EDS、XRD等测试技术表征其腐蚀特性，采用灰色关联方法计算青岛市和重庆市江津区两地室内外腐蚀行为的相关性。结果表明：在0～96 h阶段，工业大气环境中镀锌层的腐蚀深度和腐蚀速率的变化明显高于海洋大气环境。在96～120 h阶段，海洋大气环境的腐蚀速率接近工业大气环境，镀锌层在工业大气环境中锈层稀疏多孔，锈层主要成分为Zn₄SO₄(OH)₆；而在海洋大气环境中，锈层由稀疏转变成致密，Cl-易穿蚀锌层，造成铁基体腐蚀，锈层主要成分有Zn₅(OH)₈Cl₂H₂O和Fe(OH)₂。分别得到江津工业、青岛海洋大气环境室内外腐蚀时间相关模型：T₀=23.55T和T₀=19.63T，室内腐蚀试验与室外暴露试验关联度大于0.6，有良好相关性，可以有效评估工业、海洋...     

海洋气候与工业废气复杂环境下罐区的腐蚀现状及防护措施

沿海环境下,化工设备腐蚀日益突出,而储罐作为化工设备的常见容器,其腐蚀严重影响生产系统的安全运行,本文通过对某沿海炼厂多台储罐的腐蚀现象宏观检查,并对其垢物进行化学成分分析,结果表明,锈层垢物中出现铁的硫酸盐成分,海洋气候与工业废气耦合环境下,更容易导致薄弱地方更容易出现腐蚀,同时从技术和管理角度对腐蚀原因进行综合分析,提出相应的防护措施。     

LD10铝合金加速腐蚀试验相关模拟性研究

通过对LD10铝合金的加速腐蚀试验中腐蚀试件的失重数据和腐蚀形貌分析,研究了加速腐蚀过程的腐蚀规律,并且与实际的腐蚀试验进行了相关模拟性分析。结论表明:改变LD10的腐蚀环境条件能够与实际腐蚀试验在电化学本质、环境因素作用方式和锈层形貌分析方面保持一致,通过灰色关联度分析了得出了该加速试验的关联系数r=0.61998。     

商用车SCR系统用不锈钢的腐蚀性研究

通过实验室模拟试验,对比研究了4种常用的不锈钢(T436L、T439M、T441铁素体不锈钢和T304奥氏体不锈钢)在商用车SCR系统(选择性催化还原系统)工作环境中的腐蚀行为。通过扫描电镜和X射线衍射对样品的腐蚀形态以及产物进行表征。通过测量腐蚀前后氧化层剥落的厚度和内部腐蚀的深度对比了不同样品的耐腐蚀能力。结果显示T436L铁素体不锈钢展现出最出色的抗腐蚀性能,铁素体不锈钢的表现整体上要优于T304奥氏体不锈钢。     

水性多功能带锈防锈涂料的研制

以偏碱性的苯丙乳液为主要成膜物,优选出磷酸锌为防锈颜料,并从4种不同成分的转锈剂中选择了一种与该苯丙乳液相容性好并且转锈效果优异的转锈剂──2611,制备了水性带锈防锈涂料。研究了转锈剂2611和磷酸锌的用量、涂层的颜料体积浓度(PVC)对带锈涂料机械性能和防腐性能的影响。结果表明,当转锈剂2611的用量为配方总量的5%、磷酸锌的用量为配方总颜填料的21%、颜料体积浓度为33%时,制得了一种集渗透型、稳定型和转化型3类带锈防锈涂料特性于一体的多功能带锈防锈涂料,其综合性能较佳,耐盐雾腐蚀时间达到240 h以上,耐水性超过15 d。     

Corrosion of carbon steel influenced by anaerobic biofilm in natural seawater

The bacteria in the anaerobic biofilm on rusted carbon steel immersed in natural seawater were characterized by culturing and molecular biology techniques. Two types of anaerobic bacterium, sulfate-reducing bacteria (SRB) Desulfovibrio caledoniensis and iron-reducing bacteria Clostridium sp. uncultured were found. The compositions of the rust layer were also analyzed and we found that iron oxide and sulfate green rust were the major components. To investigate the corrosion mechanisms, electrochemical impedance spectra was obtained based on the isolated sulfate-reducing bacteria and mixed bacteria cultured from rust layer in laboratory culture conditions. We found that single species produced iron sulfide and accelerated corrosion, but mixed species produced sulfate green rust and inhibited corrosion. The anaerobic corrosion mechanism of steel was proposed and its environmental significance was discussed.     

无氰酸性镀镉在航空航天零部件上的应用

介绍了一种用于航空航天零部件的高耐腐蚀性镀镉层结构,包括金属基体、预镀层、中间镀层、镀镉层以及钝化层,其中所述金属基体为钢铁基体和铝合金基体。对镀层结构进行中性盐雾试验2064 h其表面无白色腐蚀物生成,耐盐雾性能比航天工业部标准QJ 453-1988《镀镉层技术条件》中96 h中性盐雾试验的要求高21倍。这种保护层在耐腐蚀性上取得了重大突破,能大幅度提高航空航天零部件的使用寿命。     

不同镀层结构钢的耐盐雾腐蚀性能比较

通过盐雾试验模拟潮湿环境,对裸钢试片、电镀锌钢试片、化学镀镍-磷钢试片和化学镀镍-钴-磷钢试片进行了宏观形貌、微观形貌和腐蚀产物成分分析,比较了四个试片的耐盐雾腐蚀性能。结果表明:在盐雾环境中,四个试片均会发生电化学腐蚀,生成不同的腐蚀产物;在盐雾腐蚀周期内,裸钢试片的腐蚀速率最高,化学镀镍-磷钢试片和化学镀镍-钴-磷钢试片的腐蚀速率较低;四个试片在腐蚀过程中的阳极反应和阴极反应不同,腐蚀后的微观形貌存在明显差异。     

Rust morphology characterization of silicone-based marine antifouling paints after salt spray test on scribed specimens

A newly developed, silicone-based, marine antifouling coating, containing 0.56% immobilized Econea, was examined in terms of its anticorrosion performance. The novelty of the experimental formulation arises from the immobilization of the biocide which minimizes leaching and was accomplished via a newly developed functionalization method, based on reaction of the biocide with highly reactive isocyanate functionality. The painting system was applied on steel specimens, then scribed with a sharp cutter and examined for 12 weeks in cyclic salt spray exposure. Identification of the rust morphologies was done with XRD, Raman spectroscopy, SEM and EDS methods. The observed paint swelling during the experiment caused the formation of large, coarse rust agglomerates without adherence, which detached frequently causing reinitiation of the corrosion process. This procedure was revealed by the oxyhydroxide nature of the corrosion products. The basic corrosion morphology observed was a mixture of akaganeite and goethite. A commercial, silicone-based, foul-release coating served as a reference. The experimental formulation exhibited superior anticorrosion performance overall, since the reference system presented higher enlargement of the scribed areas, increased substrate material loss, a highly inhomogeneous corrosion layer with voids and smaller (stable) goethite amounts in the rust areas containing mainly akaganeite/goethite mixture.     

Hydrogen entry into Fe and high strength steels under simulated atmospheric corrosion

Electrochemical hydrogen permeation tests of Fe sheets under two cyclic corrosion test (CCT) conditions were performed to understand hydrogen entry behavior under atmospheric corrosions. Hydrogen entry into 1300 MPa-class high strength steels under two CCT conditions was also investigated using thermal desorption analysis. One CCT consisted of salt spray, dry and wet stages (Salt Spray CCT; SSCCT), and the other consisted of dry and wet stages after NaCl deposition (Dry–Wet CCT; DWCCT). The corrosion rates of Fe and the steels were almost constant under SSCCT and they decreased under DWCCT with time. Nevertheless, both CCTs resulted in increases in hydrogen permeation current and diffusible hydrogen content with time indicating enhancement of hydrogen entry. Corrosion current monitored by means of an atmospheric corrosion monitoring sensor consisting of Fe anode and Ag cathode decreased obviously under dry stage of the CCTs, whereas hydrogen permeation was high at the beginning of the dry stage. The discrepancy between hydrogen entry and corrosion rate indicates that the hydrogen entry is not directly controlled by corrosion rate. Increase in acidity of underlying rust layer with growth of rust layer monitored using a W/WO₃ electrode is considered to be one of the factors affecting the hydrogen entry efficiency.     

Mechanical properties of the rust layer induced by impressed current method in reinforced mortar

This paper describes the mechanical effects of rust layer formed in reinforced mortar through accelerated tests of corrosion. The morphological and physico-chemical properties (composition, structures) of the corrosion system were characterized at different stages by using optical microscope and scanning electron microscope coupled with energy dispersive spectroscopy. The corrosion pattern was mainly characterized by a rust layer confined at the interface between the steel and the mortar. Expansion coefficient of rust products was determined from the rust thickness and the Faraday's law.Furthermore, in order to understand the mechanical effects of corrosion on the damage of mortar, displacement field measurements were obtained by using digital image correlation. An analytical model (hollow cylinder subjected to inner and outer pressures) was used with a set of experimental data to deduce the time of cracking and the order of magnitude of the mechanical properties of the rust layer.     

45钢与QT450-10的表面耐腐蚀处理工艺及性能研究

针对注塑机零件中常用的材料45钢和QT450-10,采用未经热处理的模拟试样,分别进行两组不同工艺参数的软氮化及磷化（发黑）和浸涂防锈油等处理方式。最后使用中性盐雾腐蚀试验评估各试样获得的耐腐蚀性能。研究表面：采用相同的表面处理工艺,45钢的耐腐蚀性能优于QT450-10;QT450-10未经磷化（发黑）处理,无论是否浸涂防锈油,表面耐腐蚀性均很差。     

水性锈转化涂料的制备及性能

采用苯丙乳液与改性苯丙乳液共混作为成膜物质,以单宁酸为转锈剂,柠檬酸为配位剂,焦性没食子酸为转锈促进剂,再加入成膜助剂、有机胺类缓蚀剂、渗透剂等,制备了一种可应用于带锈钢材的水性锈转化涂料。通过正交试验和单因素试验确定了涂料的最优配方为:成膜物质65%,转锈剂5%,转锈促进剂2%,缓蚀剂0.6%,渗透剂2%,配位剂0.5%,成膜助剂1.6%,蒸馏水余量。采用塔菲尔极化曲线测量、中性盐雾试验和盐水浸泡试验考察了漆膜的耐蚀性。结果表明,所制水性锈转化涂膜可耐盐雾96 h,耐盐水浸泡168 h,且耐酸性较强,在pH为2的3.5%NaCl溶液中有保护作用。与两款市售涂料相比,该自制水性锈转化涂料具有更好的耐蚀性。     

高耐蚀性镀锌白钝化后处理工艺

镀锌层经白色钝化后，中性盐雾试验出现白锈的时间仅为4h，为提高其耐蚀性，采用高耐蚀性镀锌蓝钝与封闭处理相结合，介绍了工艺过程及操作条件，分析了影响膜层耐蚀性的因素。结果表明：采用该工艺能得到白色封闭膜，中性盐雾试验48小时后不出现白锈。