碳钢—硝酸体系腐蚀与缓蚀行为研究

采用失重法、容量法和电化学方法研究了碳钢在50g/kg HNO_3中的腐蚀行为,并对Lan-5在碳钢—50g/kg NHO_3体系中的缓蚀行为进行了初步探索研究.实验结果表明:碳钢在50g/kg HNO_3中的阳极腐蚀产物是Fe~(3+),阴极反应主要不是析氢反应.Lan-5是碳钢—50g/kg HNO_3体系的高效缓蚀剂,其缓蚀效率可达到99.9%,缓蚀剂之间具有显著的协同作用.研究结果还发现,碳钢在硝酸—Lan-5介质中有孔蚀倾向,阳极极化加速孔蚀的形成.

A study on corrosion and inhibition of carbon steel in nitric acid

The corrosion behaviour for carbon steel in 50 g/kg nitric acid was studied by weight loss method, gasometric method and electrochemical measurment, and the corrosion inhibition of inhibitor Lan-5 in this system was preliminarily explored. The results show that corrosion product on the anode is Fe3+ for carbon steel in 50 g/kg nitric acid and the reaction on the cathode is not mainly hydrogen evolution. Lan-5 is an efficient inhibitor which inhibition efficiency reaches 99. 5% and there is remarkable synergetic effect among its components. The results also prove that carbon steel has tendency of pitting corrosion in nitric acid containing Lan-5 and anodic polarization can speed up the initiation of pits.