湿热海洋大气中SO_2污染对Q235B钢腐蚀行为的影响  

Effect of SO_2 pollution on corrosion behavior of Q235B steel in hot and humid marine atmosphere

作　　者：李东亮[1] 付贵勤[1] 朱苗勇[1] 张贺佳[2] 

机构地区：[1]东北大学冶金学院,辽宁沈阳110819 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《钢铁》2017年第1期64-70,共7页Iron and Steel

基　　金：国家自然科学基金资助项目(51304040);教育部基本科研业务费资助项目(N150204008)

摘　　要：以NaCl和NaHSO_3为介质,采用干/湿周浸加速腐蚀试验、腐蚀失重分析、XRD、SEM等,研究了湿热海洋大气中SO_2对Q235B钢腐蚀行为的影响。结果表明,SO_2污染使Q235B钢的腐蚀明显加重。污染前后,Q235B钢的腐蚀过程均遵循幂函数W=Atn的分布规律,腐蚀产物均由非晶和少量Fe_3O_4、α-Fe OOH、β-FeOOH、γ-FeOOH晶体组成,但参数A、n值和晶体数量并不相同。Cl-和SO_2在腐蚀过程中具有协同作用,但作用机理不同。Cl-会阻止腐蚀产物吸附,并促使其脱落,进而阻止保护性锈层形成;而SO_2在酸化过程中会与钢基体和锈层反应,进而破坏锈层结构,加剧钢的腐蚀。SO_2还能抑制β-FeOOH并促进α-Fe OOH的生成,进而抑制Cl^-的破坏作用并改善锈层的稳定性;但随锈层增厚,SO_2的抑制作用减弱,内锈层随之变疏松。The effect of SO2 on the corrosion behavior of Q235B steel in simulated marine atmosphere was investigated by XRD, SEM, mass loss analysis and a wet/dry alternate immersion corrosion test using 0.1 mol/L NaCl solution and 0.1 mol/L NaCl＋0.01 mol/L NaHSO3 solution. The results indicate that SO2 pollution significantly increases the corro- sion depth of Q235B steel. The corrosion processes of Q235B steel show a good agreement with the power function of W=At＂, and the corrosion products are mainly composed of amorphous phase and a small amount crystals of Fe304, α- FeOOH, β-FeOOH, γ-FeOOH. However, the values of parameters A, n and the amount of each crystal are changed be- fore and after SO2 pollution. SO2 and Cl- are synergies in the corrosion process of Q235B steel, but their mechanisms of action are different. CI can prevent the adsorption of corrosion products, and promote them falling, thereby inhibiting the formation of protective rust layer. While SO2 will react with the steel substrate and rust layer during its acidification process, which will lead to the destruction of rust layer structure and the deterioration of corrosion resistance of the steel. In addition, SO2 can inhibit the formation of β-FeOOH and promote the formation of ct-FeOOH generated, there- by inhibit the role of Cl and improve the stability of the rust layer. However, as the rust layer thickness increases, the inhibition of SO2 reduces, and the inner rust layer becomes loose.

关 键 词：海洋大气 SO2污染 锈层 协同作用 

分 类 号：TG172[金属学及工艺—金属表面处理]