针对广西壮族自治区不同区域的气候特征，选择城市、工业、海岸3种典型大气环境开展了耐候钢的初期腐蚀行为研究。分别采用大气暴露腐蚀试验和电化学测量试验对550 MPa 强度级别的550NH耐候钢的耐腐蚀性进行评估。结果表明，550NH耐候钢在城市大气、工业、海岸3种环境中的腐蚀速率依次增加。550NH耐候钢在3地腐蚀6个月后的腐蚀产物主要为Fe₃O₄、α-FeOOH、γ-FeOOH。腐蚀产物层致密且无贯穿性裂纹主要归因于550NH耐候钢中Cu和Cr元素对裂纹和孔洞的修复作用。550NH在模拟海洋环境和模拟工业环境中的电化学阻抗谱随着腐蚀时间的延长逐渐由1个容抗弧转变为2个容抗弧组成。

According to the climatic characteristics of different regions in the Guangxi Zhuang autonomous region, the initial corrosion behavior of weathering resistant steel was studied in urban, industrial and coastal three typical atmospheric environments. The corrosion resistance of 550NH weathering steel with a strength level of 550 MPa was assessed through atmospheric exposure corrosion tests and electrochemical measurements. Results showed that the corrosion rate of 550NH weathering steel successively increased in urban, industrial and coastal environments. After six months of corrosion in three locations, the main corrosion products of 550NH weathering steel were identified as Fe₃O₄, α-FeOOH and γ-FeOOH. The corrosion product layer, being dense and devoid of penetrating cracks, was primarily attributed to the reparative effects of Cu and Cr elements on cracks and voids in 550NH weathering steel. With the extension of corrosion time, the electrochemical impedance spectra of 550NH in simulated marine and simulated industrial environments gradually transitioned from a single capacitive arc to a configuration of two capacitive arcs.