Li Xuan, Zhang Pei, Huang Huiju, Hu Xiaochen, Zhou Yong, Yan Fuan
Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology Wuhan 430205 China
College of Chemistry and Food Science, Yulin Normal University Yulin 537000 China.
RSC Adv. 2019 Nov 28;9(67):39055-39063. doi: 10.1039/c9ra08482g. eCollection 2019 Nov 27.
In this study, the influences of different pH values on the corrosion and passivation behaviors of a Q235 carbon steel in HNO-NaNO, HAc-NaNO and HCl-NaNO solutions were studied by electrochemical methods. The manifestations of the electrochemical characteristics were revealed and the variations in the electrochemical parameters were clarified. Moreover, for the Q235 steel in the three solutions with different pH values, the decrease in the corrosion current density ( ) and the increase in the charge transfer resistance ( ) in each solution, indicated a decrease in the corrosion rate. The decrease in the critical passivation current density ( ) and increase in the passive film resistance ( ) suggested the reinforcement of passivation capability. On the other hand, in the three solutions at the same pH value, the corrosion rate increased and the passivation capability weakened in HNO-NaNO, HAc-NaNO and HCl-NaNO solutions. Simultaneously, the related electrochemical mechanisms of corrosion and passivation for Q235 carbon steel in acidic solutions containing nitrite anions (NO ) were also discussed.
在本研究中，采用电化学方法研究了不同pH值对Q235碳钢在HNO-NaNO、HAc-NaNO和HCl-NaNO溶液中的腐蚀和钝化行为的影响。揭示了电化学特性的表现，并阐明了电化学参数的变化。此外，对于Q235钢在三种不同pH值的溶液中，每种溶液中腐蚀电流密度（ ）的降低和电荷转移电阻（ ）的增加表明腐蚀速率降低。临界钝化电流密度（ ）的降低和钝化膜电阻（ ）的增加表明钝化能力增强。另一方面，在相同pH值的三种溶液中，HNO-NaNO、HAc-NaNO和HCl-NaNO溶液中的腐蚀速率增加，钝化能力减弱。同时，还讨论了Q235碳钢在含亚硝酸根阴离子（NO ）的酸性溶液中的相关腐蚀和钝化电化学机理。
