Learn about the basic types of gold corrosion

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Learn about the basic types of metal corrosion. 1. Pitting corrosion: Also known as hole corrosion, it is a form of localized corrosion that results in pinhead-shaped, dot-like, or hole-like defects on the metal surface. Pitting corrosion is a unique form of anodic reaction; it is a autocatalytic process, meaning that the conditions created by the corrosion process within the pitting holes both promote and are sufficient to sustain the continued progress of corrosion. 2. Uniform corrosion: In solutions such as phosphoric acid and sodium hydroxide, the oxide film on aluminum dissolves, resulting in uniform corrosion, with a consistent dissolution rate. An increase in solution temperature and a rise in solute concentration accelerate the corrosion of aluminum. 3. Crevice corrosion is a type of local corrosion. In an electrolyte solution, corrosion that occurs within gaps formed between metals or between a metal and a non-metal, where the width of these gaps is sufficient for the electrolyte to penetrate and remain stagnant, is known as crevice corrosion. 4. Stress corrosion cracking (SCC) is a type of failure that occurs in metals under the combined action of stress (tensile stress or internal stress) and a corrosive environment; this phenomenon is known as SCC. SCC is characterized by the formation of corrosion-mechanical cracks, which can develop along grain boundaries or spread through the grains. Since crack propagation occurs within the metal, it reduces the strength of the metal structure; in severe cases, sudden failure can occur. SCC occurs under certain conditions, and these are: a certain tensile stress or residual stress within the metal.