Evaluate On The Corrosion Inhibition Of2-Mercaptobenzimidazole And Its Complex Inhibitors In The Solution Of Acid Subject To Crude Oil Chlorine Corrosion

Metallic materials play an important role in the national industry, involving machinery manufacturing materials, medical materials, bio-materials and so on, however, in the chemical industry as the vital part of reactors such as pipeline, catalytic cracking unit, effect on safety and capital consumption. The metal equipment were eroded and damaged by organic corrosive in oil and inorganic salts corrosive in water for crude oil in the progress of mining and long-haul transport, particularly chlorine generate blockage, perforation, fracture and other results for metals. For this situation, we usually utilize changing material stress intensity, coating protective, repacement matericals and add corrosion inhibitor. But corrosion inhibitor protect the metals without changing the properties of metallic materials, and adapt to the complex and labile corrosion environment, many companies have adopted it as one of effective ways to sovle the problems.With5electrochemical methods, including the weight-loss modus and the modus of corrosion rate assessment, this paper analyses and estimates the corrosion inhibition properties of2-Mercaptobenzimidazole; changes the experimental temperature or pH to examine the relationship between corrosion ability with them; simultaneously compounds2-Mercaptobenzimidazole with sodium molybdate, propargyl alcohol and CTAB respectively for binary composite to inspect the relationship between concentrations and inhibition efficiency; investigate the corrosion inhibition effect of quaternary composite in accordance with the L9(34) orthogonal experiment designed; examines the strength of the adsorption abilities for metallic surface of different corrosion inhibitors in solution with surface tension method.Experiments showed that for a given concentration of corrosion inhibitor, changing the temperature or pH can have a significant impact on inhibition efficiency, chiefly affecting the adsorption abilities for metallic surface of inhibitor; when2-Mercaptobenzimidazole is used alone, it has the extreme concentration for316L, N80steel and20#steel, and inhibition efficiency will decrease if it becomes more than the extreme concentration; the inhibition efficiency is superior to the one-component corrosion inhibition efficiency after compounded with sodium molybdate, propargyl alcohol and CTAB; the primary and secondary factors effecting the inhibition efficiency of every carbon steel are absolutely distinct after quaternary composite, so we can determine the optimization compound combination;2-Mercaptobenzimidazole can still inhibited the pitting corrosion of the carbon steel in the solution of oil-water mixture, and the degree of corrosion of the mixture emulsion of oil-water mixture is less than that of pure water.2-Mercaptobenzimidazole is also an ideal oil-soluble inhibitor and it has reference value for solving the problem of corrosion of the petrochemical equipment.