RESTRAINING METHOD FOR CORROSION OF STEEL MATERIAL AGAINST SOLUTION CONTAINING SOUR GAS

摘要

PURPOSE:To restrain the corrosion and hydrogen-induced crack of steel material which is in contact with sour soln., by addition of an imidazoline derivative of specific structure to a soln. contg. sour gas. CONSTITUTION:A quarternary imidazoline derivative having structure shown by a formula, at least one member among the substituted groups R1-R7 of which is aliphatic, acyclic, or aromatic hydrocarbon group having =5 carbon atoms, is added to a sour soln. in a quantity =20ppm. Said derivative is synthesized by the reaction of halogenated hydrocarbon and an imidazoling derivative made by the dehydration of an aliphatic acid and polyethylenepolyamine. Nitrogen atoms contained in the molecules of said derivative are adsorbed to the surface of steel material and its long-chain substituting group having hydrophobic property shuts off causative material of corrosion. Hence corrosion of steel material and intrusion of hydrogen into steel material by the sour soln. having strong corrosiveness is also sufficiently restrained.