【摘要】 采用硅藻土模拟法研究了Q235,A1和A2钢在模拟酸性土壤中的腐蚀行为,对比分析了材料的腐蚀失重,利用扫描电镜(SEM)和X射线衍射(XRD)等方法研究了材料的腐蚀形貌及腐蚀产物。结果表明,在模拟酸性土壤中,Q235,A1和A2钢周期360h的腐蚀速率别为0.48,0.14和0.097mm/a。碳层分析表明,降低碳含量有助于减少钢中的微电池腐蚀;Cr的加入可以提高基体的自腐蚀电位;腐蚀后内锈层位置Cr的富集可以提高锈层的致密性,并改变点蚀的扩展方式;3种材料主要腐蚀产物均为α-FeOOH,γ-FeOOH和Fe3O4,其中A1和A2钢内锈层腐蚀产物中α-FeOOH比例增大,其α/γ-FeOOH比值约为Q235的10倍,腐蚀产物保护性更优。更多还原

【Abstract】 The corrosion behavior of a commercial carbon steel Q235, and two new steels A1 and A2 in an artificial soil, which consisted of diatomite and appropriate acid solution to simulate a typical acidic soil at Southern China was studied by mean of corrosion weight loss measurement, and then the corrosion morphology and products were characterized by SEM and XRD. The results showed that the corrosion rate of Q235, A1 and A2 steel in the simulated acidic soil was 0.48, 0.14 and 0.097 mm/a respectively after 300 h corrosion; the tendency to micro-cell corrosion of a steel can be lowered as the carbon content of the steel has been reduced; an appropriate addition of Cr can shift positively the corrosion potential of the matrix; the enrichment of Cr in the inner portion of the rust scale can improve its compactness, and change the propagation mode of corrosion pits;the corrosion products of Q235, A1 and A2 steel were mainly consisted of α- Fe OOH, γ- Fe OOH and Fe3O4, however, the corrosion products of A1 and A2 steels possess a ratio of α-Fe OOH to γ-Fe OOH ca 10 times higher than that of Q235 steel, which implying a better protectiveness of the rust layers for the two new steels.更多还原