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

Abstract

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 SO2 and NO2 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.

Keywords

• atmospheric corrosion|northern hebei region|atmospheric environment|corrosion rate