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Corrosion inhibition is the process by which a substance, the corrosion inhibitor, added in small concentration to a corrosive environment reduces the rate at which a metal undergoes electrochemical degradation, by interacting with the metal surface or with the electrochemical reactions occurring at the interface ^[1]. Inhibitors act by adsorbing onto the metal surface to form a protective film that blocks anodic dissolution sites, by suppressing the cathodic reduction reaction, by passivating the surface through formation of an insoluble layer, or by scavenging corrosive species, so that the corrosion current and hence the penetration rate are lowered without necessarily preventing corrosion entirely ^[2]. The mechanism is fundamentally interfacial: the inhibitor molecule or ion competes with water and aggressive ions for surface sites, and its effectiveness depends on adsorption strength, surface coverage, and the nature of the electrolyte and the metal, rather than on changing the bulk corrosive medium ^[1]. Corrosion inhibition is distinguished from coatings and barrier protection by the fact that the active agent is dissolved or dispersed in the environment and functions through surface adsorption and electrochemical interference, and it is characterized by the degree to which it slows the anodic and cathodic half-reactions at the corroding interface ^[2]. It is quantified as a reduction in corrosion rate relative to the uninhibited medium ^[3].