Q235钢在实际土壤与模拟溶液中的腐蚀行为

对比分析了Q235钢在实际土壤和模拟溶液中的腐蚀行为,计算了其腐蚀失重,利用SEM和XRD方法分析了两种腐蚀介质中Q235钢的锈层形貌、物相结构及相对含量,并分析了不同介质中材料的极化曲线。结果表明:Q235钢在两种不同腐蚀介质中的腐蚀行为存在较大差异。Q235钢在模拟溶液中的腐蚀速率远高于实际土壤,至周期360h达到0.413mm/a,约为实际土壤的4.5倍;Q235钢在实际土壤中呈蚀斑相连长大扩展的腐蚀形貌,其腐蚀产物为α-FeOOH、γ-FeOOH、Fe3O4和Fe2O3;模拟溶液中试样为均匀腐蚀形貌,阴极过程主要受析氢控制;随腐蚀周期的延长,内锈层中生成结晶性良好的Fe3O4,降低了试样的腐蚀速率。

Corrosion Behavior of Q235 Steel in Actual Soil and Simulated Solution

The corrosion behaviors of Q235 steel in actual soil and simulated solution were compared and analyzed, corrosion weight losses were calculated, corrosion morphologies and products were analyzed by SEM and XRD, and polarization curves of Q235 steel in actual soil and simulated solution were studied. The results indicate that there is a big difference between the corrosion behaviors of Q235 steel in two different corrosive medias. Corrosion rate of Q235 steel in simulated solution is much higher than that one in actual soil, which arrives 0. 413mm/a after etching time of 360h and nearly 4. 5 times of the value in actual soil. The corrosion morphology of Q235 steel in actual soil is mainly corrosion spots with extending and connecting modes, and its corrosion products are ??-FeOOH, ??-FeOOH, Fe3O4 and Fe2O3. However, the corrosion morphology of Q235 steel in simulated solution is uniform corrosion, and its cathode process is mainly controlled by hydrogen evolution. With the corrosion time extension, Fe3O4 with good crystallinity is generated in inner rust layer, which could reduce the corrosion rate of Q235 steel.