摘要
研究了在 NaHCO_3-Na_2SO_4体系中,温度、pH 值、侵蚀性离子(Cl,S^(2-),HCO_3,NO_3^-,CO_3^(2-))以及缓蚀性离子(MoO_4^(2-),NO_2^-,Cr_2O_7^(2-),Zn^(2+))对10号碳钢腐蚀速率的影响。研究结果表明,在60℃和80℃条件下,HCO_3^-离子均存在着一个临界浓度(约0.1 mol/L),当 HCO_3^-离子浓度等于0.1 mol/L 时,腐蚀速率很小,几乎为零;当 HCO_3^-离子浓度低于或高于此浓度时腐蚀速率都有所增大,但当浓度达到0.2 mol/L 时腐蚀速率有下降趋势,说明高浓度的 HCO_3^-离子对碳钢具有一定的保护性。侵蚀性离子对碳钢腐蚀作用由小到大的顺序为:Cl^-<NO_3^-<S^(2-)<CO_3^(2-)。MoO_4^(2-),NO_2^-,Zn^(2+)等缓蚀性离子,可以通过提高溶液的 pH 值,在碳钢表面生成保护膜等对碳钢起到保护作用;而 Cr_2O_7^(2-)却能降低溶液的 pH 值,促进碳钢的腐蚀。
Factors influenced the corrosion rate of 108 carbon steel in the system of NaHCO3- Na2SO4 solution, such as temperature, pH value, corrosive ions （Cl^-, S^2- , HCO3^- , NO3^- , CO3^2- ） and rust inhibitive ions（MoO4^2- ,NO2^- ,Cr2O7^2- ,Zn^2＋）,were investigated. Results showed that at 60 ℃ and 80 ℃ with a critical HCO/ concentration of 0.1 mol/L,the corrosion rate of 10^# carbon steel was almost zero; when HCO3^- concentration was higher or lower than 0. 1 mol/L, the corrosion rate increased; when HCO3 concentration reached 0. 2 mol/L, the corrosion rate seemed to have a decrease trend, which indicated that high concentration of HCO3^- ions could suppress the corrosion of carbon steel by forming a passivation film. The erosion of corrosive ions to carbon steel increased from low to high in the order of Cl^-〈NO3^-〈S^2-〈 CO3^2-. Rust inhibitive ions,MoO4^2- ,NO2^- and Zn^2＋ ions, could protect the steel from corrosion by raising the solution pH value to form a protective film on the surface of carbon steel; yet Cr2O7^2- ions would decrease the pH value of the solution,and thus the corrosion was enhanced.
出处
《石油炼制与化工》
CAS
CSCD
北大核心
2008年第11期55-58,共4页
Petroleum Processing and Petrochemicals
基金
国家自然科学基金(20676017)
北京市属市管人才强教计划资助项目
