Definition of intergranular corrosion and pitting Characteristics

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1. Intergranular corrosion: Intergranular corrosion is a type of localized corrosion that develops along the grain boundaries of a metal or alloy, or in the areas adjacent to those boundaries; the grains themselves suffer little corrosion or no corrosion at all. 2. It weakens the bonding force between grains, making it difficult to detect. 3. It is extremely harmful. Materials, Media, Environment: An “environment that may cause intergranular corrosion” must be an electrochemical corrosion environment with an electrolyte present. Medium: The electrolytes that can cause intergranular corrosion of Type A SS are mainly acidic media, such as industrial acetic acid, formic acid, and chromic acid. Lactic acid, nitric acid, oxalic acid, phosphoric acid, hydrochloric acid, sulfuric acid, sulfurous acid, ammonium carbamate, etc ； Generally, solutions of chemically pure acetic acid, alcohols, aldehydes, ketones, ethers, benzene, phenols, alkanes, gasoline, and other gas-phase media do not cause intergranular corrosion in Type A SS. F-body SS, Ni-based alloys, Al, and its alloys all suffer from intergranular corrosion. The A-body-F-body duplex SS is currently an excellent steel grade for resisting intergranular corrosion.