大气环境改善对冀北地区Q235钢大气腐蚀行为的影响

Influence of Atmospheric Environment Improvement on Atmospheric Corrosion Behavior of Q235 Steel in Northern Hebei Region

2018~2020年间,选用Q235钢在冀北地区(唐山市、秦皇岛市、廊坊市、承德市和张家口市)进行大气腐蚀试验研究。结果表明:在2018~2020年间,Q235钢在冀北地区大气腐蚀速率由东南至西北逐渐降低,东南部地区腐蚀速率下降明显,地区性腐蚀差异逐渐变小。随着大气腐蚀速率明显降低,试验试样表面腐蚀产物从对基体保护作用较小的片状γ-FeOOH转而形成以结构致密的棉絮状α-FeOOH为主的显微结构。因节能减排治理工作的显著作用和“新冠”疫情所带来的生活、生产模式的改变,冀北地区的大气中的SO_(2)和NO_(2)含量整体呈现下降趋势,使得Q235钢在冀北地区大气腐蚀速率降低,钢结构的大气腐蚀减缓。

From 2018 to 2020, atmospheric corrosion tests of Q235 steel were carried out in northern Hebei region(Tangshan, Qinhuangdao, Langfang, Chengde and Zhangjiakou). Results showed that the atmospheric corrosion rate of Q235 steel in northern Hebei region decreased gradually from the southeast to the northwest in that period, the corrosion rate in the southeast decreased obviously, and the regional difference of atmospheric corrosion gradually grew smaller. As the atmospheric corrosion rate decreased significantly, the surface corrosion product of the test samples changed from the flaky γ-FeOOH with less protective effect on the substrate into a microstructure mainly consisted of compact cotton-like α-FeOOH. Owing to the significant effect of energy conservation and emission reduction governance as well as the change of life and production modes brought by the COVID-19 pandemic, the contents of SO_(2)and NO_(2)in the atmosphere in northern Hebei region presented a downward trend, which reduced the atmospheric corrosion rate of Q235 steel and the atmospheric corrosion of steel structure in that region.