不锈钢的大气腐蚀研究—12年暴露试验总结

A STUDY OF ATMOSPHERIC CORROSION OF STAINLESS STEELS—A SUMMARY OF 12 YEAR EXPOSURE TESTING

总结了 5种不锈钢在我国 7个试验点的 1 2年大气腐蚀试验结果。材料中包括了最常用的不锈钢。环境中包括了亚热带、温带 ,工业性、海洋性 ,干燥环境及湿热环境等各种典型环境。不锈钢在大气中是耐蚀的 ,当含Cr量达到 1 8%以上时耐蚀性很好 ,钼能明显提高不锈钢的耐蚀性 ,超低碳也能提高其耐蚀性。即使在腐蚀性最强的湿热海洋大气中 ,超低碳含钼钢 1 2年后基本保持无锈痕。灰尘的沉积及钢材表面的缺陷处是不锈钢大气腐蚀的主要起始点。在环境因素中 ,危害最大的是氯离子 ,如果再加上湿热 ,会造成严重的腐蚀。二氧化硫的影响很小。文中还讨论了不锈钢的大气腐蚀机理。

Results from 12 year atmospheric exposure of 5 types of stainless steel at 7 sites in China were summarized. The exposed steels were selected from commonly used stainless steels. The test sites represented typical environments such as temperate and subtropical, industrial and marine and rural, humid and hot. Stainless steels under study were corrosion resistant in atmosphere. When Cr content was over 18%,their corrosion behavior became excellent. Mo could raise corrosion resistance of stainless steels. Extra low carbon content in the steels could further raise their corrosion resistance. Even in humid and hot marine environment of high corrosivity,the steel with extra low carbon and some molybdenum did not corrode after 12 year exposure. Deposited dust and surface defect were the main places of origin of atmospheric corrosion for stainless steels. Among various environmental factors affecting atmospheric corrosivity, Cl - was most important. The humid and hot environment and the presence of Cl - resulted in extra high corrosion rates.Besides, SO 2 had very little effect. [WT9.,12.HZ]