Atmospheric corrosion nitrogen-containing compounds

Fig. 10.4 Formation of nitrogen-containing compounds during atmospheric corrosion of iron and...

However, the principal disadvantages at present to the use of liquid lithium as a coolant appear to arise from chemical properties. A review of the published literature reveals that liquid lithium is highly corrosive. However, these data are subject to question, in view of the fact that the amount of contained impurities was not accurately reported. Lithium is highly reactive with most of the major constituents of the surrounding atmosphere—oxygen, nitrogen, and water. The lithium compounds of these elements therefore are usually present in lithium as impurities. All of these compounds of lithium can be expected to react with most materials of construction at elevated temperatures. To the authors knowledge, literature published to date does not cover the rate of corrosion by molten lithium metal in relation to the contained impurities. 

One of the most important factors affecting atmospheric corrosion is the presence of specific pollutants. In areas having low atmospheric pollution, corrosion rates are correspondingly low. The presence of atmospheric pollutants such as the various oxides of nitrogen, sulfur-containing compounds, chlorine-containing compounds, and other less common pollutants will stimulate corrosion. 

Industrial environments contain sulfur compounds, nitrogen compounds, and other acidic agents that can promote the corrosion of steels. In addition, industrial environments contain a heavier loading of airborne particles, which also contribute to corrosion. Urban environments are comparable with industrial, but the amount of pollution will be less intense. Marine environments are characterized by the presence of chloride, an ion that is particularly detrimental to the corrosion resistance of steels. Rural and indoor environments are the least corrosive of the atmospheric environments. 

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