Evaluation of titanium in hydrochloric acid solutions containing corrosion inhibitors

Currently, the use of titanium alloys components and coating (clad) in petroleum subsea production systems continues to increase.Titanium alloys are lightweight, very flexible; have greater mechanical resistance relationship showing excellent resistance to corrosion and fatigue in ambient seawater and marine environments.The rate of corrosion of titanium alloys are low for hydrochloric acid (3%), however, in the acidification operations from petroleum well is necessary the use of corrosion inhibitors, because the concentration of hydrochloric acid varies from 10 to 28%.A corrosion inhibitor for acidification can be defined as a substance or mixture of substances which are added to the corrosive medium aim inhibit or minimize the action of the corrosive medium.This paper presents the laboratory tests made with titanium coupons subjected to hydrochloric acid solution 10% (weight %), in temperatures of 50° C and 70° C, and additions of phenylamine (aniline), thiocarbamide and β-naphthol as corrosion inhibitors.The results showed that the corrosion protection inhibitors exerted by varies from 50 to 80% depending on the concentration of inhibitors and temperatures used in the tests.