通过暴晒试验、宏观形貌观察、拉曼光谱分析及电化学测试等研究了Q420碳钢在四川雅江和理塘地区大气环境中暴露1 a后的腐蚀行为。结果表明:在两个地区大气环境中暴露1 a后,该钢表面均有较为明显的锈层,其在雅江和理塘地区的平均腐蚀速率分别为23. 75 g/(m² ·a)和8. 48 g/(m² ·a)。暴晒1 a后,该钢表面腐蚀产物主要由γ-FeOOH、α-FeOOH和γ-Fe₂O₃组成,理塘地区的腐蚀产物出现了α-Fe₂O₃。在理塘大气环境中的Q420碳钢表面腐蚀产物电阻和表面电荷转移电阻均大于在雅江大气环境中的,即在理塘环境中暴晒1 a后,试样表面腐蚀产物对基体的保护作用相对较好,可减缓碳钢表面的进一步腐蚀。

The corrosion behavior of Q420 carbon steel in the atmospheric environment of Yajiang and Litang areas in Sichuan Province after 1 year of exposure was studied through exposure tests, macro morphology observation, Raman spectroscopy analysis, and electrochemical testing. The results showed that after being exposed to the atmospheric environment for one year in both regions, there was a significant rust layer on the surface of carbon steel. The average corrosion rates in Yajiang and Litang were 23. 75 g/(m² ·a) and 8. 48 g/(m² ·a), respectively. After 1 year of exposure to sunlight, the corrosion products on the surface of carbon steel were mainly composed of γ-FeOOH, α-FeOOH and γ-Fe₂O₃, α-Fe₂O₃ appeared in corrosion products after corrosion in the Litang area. The surface corrosion product resistance and surface charge transfer resistance of the steel in the Litang atmospheric environment were both higher than those in the Yajiang atmospheric environment. That means that, after exposure to sunlight for 1 year in the Litang environment, the surface corrosion product of the sample had a relatively good protective effect on the substrate, which could slow down further corrosion of the carbon steel surface.