A3钢的氧浓差宏电池腐蚀作用的研究

模拟埋地钢管上可能形成的宏电池现象,在实验室以3.5%NaCl溶液和自制装置研究了O₂/N₂、O₂/空气和N₂/空气3种金属的腐蚀强度变化。分别测定了i_g~t和E_g~t行为及阳极金属的失重腐蚀速度;提出了宏电池效应系数(r=i_a^A/i_k^A),并用来表征宏电池实际作用强度证明其相关性良好。结果表明,3种宏电池的作用规律相同,且随氧浓差异增大,宏电池效应系数也增大,这时宏电池中阳极金属的腐蚀显著加速。

Investigation on Oxygen Concentration Difference Macrocell Corrosion for Stcei A3

The behaviour and mechanism of the oxygen concentration difference macrocell were investigated for steel A₃ in the 3.5% NaCl solution by the self-made equipment.Three kinds of macrocell:O₂/N₂,O₂/air,N₂/air macrocells were formed.The i_g~t,E_g~t curves were recorded in the experiments.The coefficient of the macrocell corrosion effect, r=i_a^A/i_k^A, was proposed for calculation of the effect intensity of macrocell.The results show that the effect behavior of these macorcells was the same,and all macrocells accelerated the corrosion rate of the anodic metal in macrocells.The correlation between the value of coefficient r and the real intensity of macrocell was testified to be relatively satisfactory.