• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Marine atmospheric corrosion initiation and corrosion products characterization.
【24h】

Marine atmospheric corrosion initiation and corrosion products characterization.

机译：海洋大气腐蚀引发和腐蚀产物表征。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This work focused on NaCl particle-induced marine atmospheric corrosion of carbon steel. Corrosion does not initiate under deliquescent NaCl droplets smaller than a critical size. The mechanisms of corrosion initiation and propagation were identified. The effects of diverse natural environments on the formation and aging of iron oxide products were identified.;Part I. On carbon steel that were exposed to Hawai'i's marine test sites for 30 min, corrosion did not initiate under small seawater droplets (D ∼30 microm) but occurred under larger droplets. Similarly, laboratory study showed that corrosion did not initiate from small NaCl droplets (D ∼45 microm) formed by the deliquescence of pre-deposited NaCl particles upon exposing to high humidity (RH > 80%), while occurred under larger droplets and sometimes propagated in the form of filiform corrosion. In addition, anodic polarization showed the steel passivated under small NaCl droplets and corroded actively under larger droplets.;In situ and ex situ Raman spectra from the rust species that formed during the corrosion process showed that green rust (GR) formed close to the corrosion pit (i.e., anodic site) while lepidocrocite (gamma-FeOOH) clusters precipitated in regions outside of the GR region (i.e., cathodic site). Similarly, the rust formed in Evans' droplet experiments was also indentified as GR and lepidocrocite using In situ Raman spectroscopy.;Part II. The corrosion products formed on 1008 steel that were exposed to Hawai'i's diverse micro-climates for 1 year period were characterized using micro-Raman analysis, energy dispersive X-ray analysis (EDXA), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis.;Lepidocrocite was identified as the major rust in the surface layers on samples exposed to industrial, rainforest, dry and agricultural test sites, while goethite was detected in the inner rust layers. Akaganeite with high concentration of Cl was also found on the face-down sides of samples from dry and agricultural test sites.;In addition to the dominant rust phases---lepidocrocite in the surface rust layers and goethite in the inner rust layers---more akaganeite was detected on samples from marine test sites, both in the surface and inner rust layers, due to high airborne chlorinity.
机译：这项工作的重点是NaCl颗粒引起的碳钢海洋大气腐蚀。在小于临界尺寸的潮解性NaCl液滴下不会发生腐蚀。确定了腐蚀引发和扩散的机制。确定了不同的自然环境对氧化铁产物的形成和老化的影响。第一部分：在暴露于夏威夷的海洋测试地点30分钟的碳钢上，在小水滴下未发生腐蚀（D <约30微米），但出现在较大的液滴下。同样，实验室研究表明，暴露于高湿度（RH> 80％）时，预沉积NaCl颗粒潮解后形成的小NaCl小滴（D <〜45微米）不会引起腐蚀，而在大液滴下会发生腐蚀，有时以丝状腐蚀的形式传播。此外，阳极极化表明钢在NaCl小液滴下被钝化，在较大液滴下被活跃腐蚀;腐蚀过程中形成的锈物质的原位和异位拉曼光谱表明，绿色锈（GR）接近于腐蚀形成坑（即阳极位），而纤铁矿（γ-FeOOH）团簇在GR区域以外的区域（即阴极位）沉淀。同样，在埃文斯液滴实验中形成的铁锈也用原位拉曼光谱法鉴定为GR和纤铁矿。第二部分。使用微拉曼分析，能量色散X射线分析（EDXA），傅里叶变换红外光谱（FTIR）和X-射线分析法对1008钢上暴露于夏威夷不同微气候下1年的腐蚀产物进行了表征。射线衍射（XRD）分析。硅铁云母被确定为暴露于工业，雨林，干旱和农业试验场所的样品表面层中的主要锈蚀，而在内锈层中检测到针铁矿。在干燥和农业试验场所的样品的正面朝下的侧面还发现了高浓度的赤霞石;除了主要的锈蚀相-表面锈层中的锂铁云母和内部锈蚀层中的针铁矿- -由于空气中的高氯含量，在海洋测试场所的样品中，无论在表面还是在内部的锈层中，都检出了更多的赤霞石。

著录项

  • 作者

    Li, Shengxi.;

  • 作者单位

    University of Hawai'i at Manoa.;

  • 授予单位 University of Hawai'i at Manoa.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2010
  • 页码 204 p.
  • 总页数 204
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号