经济型耐大气腐蚀钢大气曝晒腐蚀性能研究

随着耐大气腐蚀钢的应用越来越广泛,掌握其耐大气腐蚀性能显得十分重要.采用电化学方法、电子探针等手段对JT345经济型耐大气腐蚀钢在北京、青岛、沈阳3地1年大气曝晒的试样进行分析研究,并采用Q235B和Corten A钢作为对比钢.电化学试验表明,大气腐蚀过程中生成的锈层,使电化学阳极过程受到显著的阻滞.电子探针与电子能谱分析结果表明,JT345钢的内锈层存在有效合金元素的富集,使内锈层结实、致密、牢固,抑制了腐蚀性物质的侵入,保护了基体金属.结果表明JT345经济型耐候钢具有优良的耐蚀性能,腐蚀率接近CortenA的水平,随着曝晒时间的延长,腐蚀率还将显著地下降,JT345钢的耐大气腐蚀的优越性将会更加充分体现出来.

Exposure Corrosion Behavior of Economical Weathering Steel

Contrasted to steel Q235B and Corten A, corrosion behaviors of JT345 economical weathering steel exposed to the atmosphere in Beijing, Qingdao and Shenyang for one year, were studied by electrochemical methods and electronprobe microanalyzer (EPMA). Electrochemical experiments approve that the corrosion rust layer in atmosphere prevents the electrochemical anodic process evidently. EPMA and EDA analysis indicate that efficient alloy elements are enriched on the inner rust layer of steel JT345 make the inner layer compacted so as to prevent the corrosion and protect the matrix metal. Results show that JT345 weathering steel has excellent corrosion resistance and its corrosion rate is near to steel Corten A. With the extension of exposure time, the advantage of JT345 steel in atmospheric corrosion resistance will adequately reveal accompanying by marked decrease of corrosion rate.