An acid corrosion inhibitor is a chemical additive used to protect metals from corrosion in acidic environments. These inhibitors work by forming a protective film on the surface of the metal, which blocks corrosive substances from reaching the metal and reacting with it. Commonly used in industries like oil and gas, water treatment, and metal cleaning, acid corrosion inhibitors help prolong the lifespan of equipment and infrastructure, reduce maintenance costs, and prevent potential failures due to corrosion.