Fundamental Studies of Localized Corrosion Site Chemistry inStainless Steel

不锈钢局部腐蚀位点化学基础研究

• 批准号: 9119304
• 负责人: Robert Kelly
• 金额: $ 20.79万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9119304&HistoricalAwards=false
• 关键词: Fundamental; Studies; Localized; Corrosion; Site

This research takes a new approach to understanding the changes occurring in solution chemistry during localized corrosion. Ion chromatography is employed to probe the progression of solution chemistry within occluded cells. Ion chromatography is capable of detecting nanogram quantities of a wide variety of ions in solution volumes as low as 10 microliters. This technique permits the analysis of changes in solution chemistry at localized corrosion sites such as in crevices. New insights can be obtained into the fundamental processes that control corrosion pit formation and propagation. Surface analysis techniques (Auger spectroscopy and X-ray photoelectron spectroscopy) are used to examine the composition of passive films and surface corrosion layers that form before and after the onset of corrosion. %%% Localized corrosion of metals and alloys in aqueous environments is an especially damaging form of environmental attack. It has generally been accepted that the cause of the initiation and propagation of a localized corrosion site is the formation of a highly aggressive environment in an occluded cell that comprises the area of attack. Understanding obtained from the approach described in this study could have a significant impact on the development of strategies for mitigating pitting and crevice corrosion.

这项研究为理解局部腐蚀过程中溶液化学的变化提供了一种新的方法。离子色谱被用来探测闭塞细胞内溶液化学的进展。离子色谱能够在低至10微升的溶液体积中检测纳克量的各种离子。这项技术可以分析局部腐蚀部位(如缝隙)的溶液化学变化。对控制腐蚀坑形成和扩展的基本过程可以获得新的见解。表面分析技术(俄歇能谱和X射线光电子能谱)用于检测腐蚀开始前后形成的钝化膜和表面腐蚀层的成分。金属和合金在水环境中的局部腐蚀是一种特别具有破坏性的环境侵蚀形式。人们普遍认为，局部腐蚀位置的起始和扩展的原因是在构成攻击区的闭塞单元中形成了高度侵蚀性的环境。从本研究中描述的方法中获得的理解可能会对制定减轻点蚀和缝隙腐蚀的战略产生重大影响。