高强度耐候钢在模拟工业大气环境下的腐蚀行为

Corrosion behavior of high strength weathering steels in simulated industrial atmosphere environment

利用周期浸润腐蚀实验和电化学方法,研究了耐候钢在模拟工业大气环境下的腐蚀演化行为,并利用光学显微镜(OM)、扫描电镜(SEM)和电子探针(EPMA)等分析了实验钢显微组织、腐蚀形貌、锈层特征及腐蚀产物中Cu元素的分布。结果表明,实验钢的组织主要由准多边形铁素体和粒状贝氏体组成;实验钢的腐蚀质量损失率随Cu含量的增加及时间的延长而逐渐降低,且其质量损失量基本相同,锈层厚度逐渐减小,致密度增加;Cu元素在锈层的缝隙和孔洞等缺陷处富集;随着腐蚀时间的增加,自腐蚀电位增大,自腐蚀电流密度下降;含Cu钢锈层促进了阴极还原过程,同时抑制了阳极氧化过程。

Corrosion behavior of weathering steels under simulated industrial atmosphere environment was investigated by alternate immersion corrosion test and polarization curve technique. Microstructure, rust layer morphology and characteristics of the high strength weathering steels and the distribution of Cu in rust layer were studied by using optical microscope, scanning electron microscopy （ SEM ） and electron probe microanalyizer （ EPMA）. The results show microstructure of the high strength weathering steels is composed of quasi polygonal ferrite and granular bainite. Corrosion rates of the test steels decrease with prolonging corrosion time and increasing Cu content, and their mass losses are almost identical. Meanwhile, the thickness of rust layer decreases and density increases. Cu is enriched at gaps and pores in rust layers. Corrosion potential increases and corrosion current decreases with prolonging time. The rust layers of the weathering steels containing Cu promote the cathode process while restrain the anodic process.