NaCl溶液中20Cr9Ni5Co14不锈钢电化学腐蚀行为研究

摘要/Abstract

摘要： 采用电化学极化技术(动电位计划技术、线性极化技术和循环极化技术)和交流阻抗技术研究了不同条件下20Cr9Ni5Co14超高强度不锈钢的电化学腐蚀行为，并采用扫描电镜对极化后腐蚀形貌进行了表征。结果表明，20Cr9Ni5Co14钢在3.5%NaCl溶液中出现钝化。随着NaCl浓度的升高，钝化现象消失，而自腐蚀电流从8.223×10-7 A/cm2减小至1.129×10-7 A/cm2；随着pH值的降低，20Cr9Ni5Co14钢的致钝电位和过钝化电位增加。在pH高于3时，腐蚀产物膜具有良好的耐腐蚀性能而导致反应步骤成为控制步骤。而当pH值降低到2时，腐蚀产物溶解速度很快，金属界面发生腐蚀速率很大，浓差极化成为了控制步骤。对腐蚀形貌研究表明，20Cr9Ni5Co14钢在极化过程中出现点腐蚀，从而导致了材料的耐腐蚀性能下降。

关键词: 电化学极化, 交流阻抗, 20Cr9Ni5Co14, 不锈钢

Abstract: The corrosion behaviors of 20Cr9Ni5Co14 ultra high strength steel were studied by using electrochemical polarization (Potentiodynamic polarization, linear polarization and cyclic polarization technologies) and electrochemical impedance spectrum methods in different conditions corrosion, and the corrosion morphologies were characterized by using scanning electron microscopy (SEM). The results showed that the passivation phenomenon of 20Cr9Ni5Co14 steel disappears with the NaCl concentration increased while it appears in 3.5% NaCl solution. The corrosion current reduces from 8.223 × 10-7 A/cm2 to 1.129 × 10-7 A/cm2 with increasing NaCl concentration. The passivation potential and over passivation potential of 20Cr9Ni5Co14 steel increase with the increase of hydrogen ion concentrations. When the pH is higher than 3, the corrosion product film having excellent corrosion resistance which leads to the electrochemical polarization step as limited step, while the pH value reached 2, the corrosion products dissolute and the polarization caused by concentration differences becomes limited step. Corrosion morphology studies showed that the corrosion of 20Cr9Ni5Co14 steel in the polarization process oriented from pitting corrosion, which leads to reduction of corrosion resistance.

Key words: Electrochemical polarization, Electrochemical impedance spectroscopy, 20Cr9Ni5Co14, stainless steel

文陈许广兴刘建华陈亚争. NaCl溶液中20Cr9Ni5Co14不锈钢电化学腐蚀行为研究[J]. .

参考文献

[1] 柳木桐,刘建华,钟平. 超高强度钢耐腐蚀性能研究进展[J]. 科技导报,2010,28(9):112-115
[2] 汤智慧,陆峰,张晓泛等. 航空高强度结构钢及不锈钢防护研究与发展[J]. 航空材料学报,2003,23(1):261-266
[3] 刘亚娟,吕祥鸿,赵国仙,等. 超级13Cr马氏体不锈钢在入井流体和产出流体环境中的腐蚀行为研究[J]. 材料工程,2012, 10(1):17-22
[4] 李红梅,蔡珣,吕战鹏,等.304不锈钢在含硼和锂的高温水中应力腐蚀破裂和表层氧化膜分析[J].材料工程,2004,8(1):7-10
[5] 刘国宇, 鲍崇高, 张安峰.不锈钢与碳钢的液固两相流冲刷腐蚀磨损研究[J].材料工程,2004,11(1):37-40
[6] 董超芳, 骆鸿, 肖葵, 等.316L不锈钢在西沙海洋大气环境下的腐蚀行为评估[J].四川大学学报,2012, 44(1):179-184
[7] 孙敏, 肖葵, 董超芳, 等.300M和Cr9钢在酸性介质中的电化学性能研究[J].中国腐蚀与防护学报,2012, 32(1):449-454
[8] 黄毓辉. 304不锈钢氯离子腐蚀的力-化学行为研究[D]. 华东理工大学博士学位论文. 2011:5-15.
[9] 韩亚军,陈友媛.316L不锈钢在不同电导率海水和NaCl溶液中的电化学行为[J].材料导报B,2012,26(1):57-60
[10] 张晓蕾. 二次硬化型超高强度钢Ferrium S 53组织和力学性能研究[D]. 昆明理工大学硕士学位论文. 2010:2-10.
[11] 杨志勇, 刘振宝, 梁剑雄, 等.马氏体时效不锈钢的发展[J].材料热处理学报,2008,29(1):1-7
[12] 于美, 董宇, 王瑞阳.23Co14Ni12Cr3Mo超高强钢在模拟海水环境中的腐蚀行为[J].材料工程,2012,1(1):42-50
[13] 刘建华, 梁馨, 李松梅.硫酸盐还原菌对两种不锈钢的腐蚀作用[J].金属学报,2005,41(1):545-550
[14] 梁馨, 刘建华, 李松梅.Cl-对Cr17Ni2在硫酸盐还原菌菌液中电化学行为的影响[J].材料保护,2007,40(1): 16-19
[15] Zhong Jinyan, Sun Min, Liu Dabo, Li Xiaogang, Liu Tianqi.Effects of chromium on the corrosion and electrochemical behaviors of ultra-high strength steels[J].Corrosion Science,2010,17(1):82-89
[16] Kim Keonha, Lee Seunghwan, Nam Nguyendang, Kim Junggu.Effect of cobalt on the corrosion resistance of low alloy steel in sulfuric acid solution[J]. Corrosion Science,2011,53(1):3576-3587