带锈碳钢在稀NaCl溶液中的腐蚀行为  

Corrosion Behavior of Rusted Carbon Steel in Diluted NaCl Solution

作　　者：谢建丽[1] 金凯峰 蒋晓斌[1] 鲁俊东[1] 胡家元[2] 

机构地区：[1]苏州热工研究院有限公司,江苏苏州215004 [2]武汉大学动力与机械学院,武汉430072

出　　处：《表面技术》2014年第2期55-59,共5页Surface Technology

摘　　要：目的探索锈层对碳钢腐蚀的影响过程。方法通过失重法、表面分析、电化学测试等方法,研究碳钢在稀NaCl溶液中的腐蚀行为。结果在稀NaCl溶液中,初始产物γ-FeOOH表现为氧化剂,易还原成Fe3O4。金属表面将迅速形成黄色薄外层(γ-FeOOH层)+黑色厚内层(Fe3O4层)的双层锈层。外锈层因γ-FeOOH的还原反应而加速阴极过程;内锈层起大阴极的作用,溶解氧可以直接在其表面被还原。结论锈层将显著加速碳钢的腐蚀,最终腐蚀速率将由溶液中的氧极限扩散速率决定。防腐措施应能抑制锈层的腐蚀促进作用。Objective To investigate the influence process of rust layer on iron corrosion. Methods The corrosion behavior of carbon steel in diluted NaC1 solution was studied by weight loss method, surface analysis and electrochemical techniques. Results Experimental results showed that the initial product 3,-FeOOH worked as an oxidant and was easily reduced to Fe3 04. Hence, a double-layer rust, consisted of a thin yellow outer layer （~/-FeOOH layer） and a thick black inner layer （Fe3Q layer）, emerged rapidly on metal surface. The outer rust layer tended to facilitate the cathodic reaction via reduction of ~/-FeOOH. The inner rust layer worked as a large area cathode and dissolved oxygen was directly reduced on its surface. Conclusion Therefore, the corrosion rate of carbon steel was accelerated quickly and was finally determined by the limiting diffusion rate of dissolved oxygen. Anti-corrosion measures for iron should be aimed to reduce the promotional effect of the rust layer on metal corrosion.

关 键 词：碳钢 锈层 稀NaCl溶液 腐蚀行为 

分 类 号：TG172.5[金属学及工艺—金属表面处理]