| This thesis discusses in detail the corrosion mechanisms of metal products exposed for a period of two years in three animal buildings and one environmentally controlled building based on the analyses of the surface corrosion products using advanced surface analysis techniques. It includes not only research on the classic corrosion of metals but on the microbial-induced corrosion, which is a new area in the study of metal corrosion in animal buildings. Another feature of the thesis is a thorough study of the test environments that makes it possible to relate the corrosion mechanisms to the environments where the metals were placed. In order to conduct more controlled studies on the effect of either individual or combined factors on corrosion, a two-month simulation chamber test was carried out with ammonia being the variable, which yielded valuable information that ammonia might retard, instead of enhancing, corrosion process for uncoated 1010 carbon steel.; According to this study, the sulfate-reducing bacterial levels in all the test buildings were low (max: {dollar}1.1times 10sp4){dollar} after two year's exposure. Since it took such a long time to grow on the metal surfaces, it is difficult to estimate the long term effects of this type of bacteria on metal corrosion. Thus, it is worthwhile to study some other species of aerobic bacteria which are known to be corrosive to metals.; Due to the experimental data from this study, it could be concluded that the fundamental mechanisms of metal corrosion in animal buildings are not different from the classic corrosion mechanisms. However, this corrosion process was accelerated by some other factors typically existing in animal buildings such as gases, microbes and dust. More research is needed to determine the mechanisms of how these factors interact with moisture to accelerate the corrosion of metal products. |
