Introduction of aluminum alloy corrosion
1 point corrosion: corrosion is also known as pitting corrosion, which is a part of the formation of the metal on the tip of the needle, point, whole shape. Point corrosion is a unique form of anodic reaction. It is a kind of self catalytic process, which is caused by the corrosion process of pitting corrosion.
2. Uniform corrosion: Aluminum in phosphoric acid and sodium hydroxide solution, the oxide film will be dissolved; the occurrence of uniform corrosion, dissolution rate is uniform. The solution temperature increases, the concentration of the solute increases, and the corrosion of aluminum.
3 crevice corrosion: crevice corrosion is a localized corrosion. Metal parts in the electrolyte solution, due to the gap formed between metal and metal or metal and nonmetal and its width to the immersion medium and the medium in a stagnant state, exacerbate internal crevice corrosion phenomenon known as crevice corrosion.
4 stress corrosion cracking (SCC) of SCC was found in the early 30's of the twentieth Century. A failure of metals under the combined action of stress (tensile stress or stress) and corrosive medium is called SCC. SCC is characterized by the formation of corrosion and mechanical cracks, both along the grain boundaries, but also through the grain expansion. Because the crack propagation is in the metal interior, can make the metal structure strength is greatly decreased, when the sudden destruction.
