Industrial aluminum(aluminum plate) several common types of corrosion on the introduction
Generally speaking, the basic types of industrial aluminum(aluminum plate) aluminum(aluminum plate) a little corrosion, galvanic corrosion, crevice corrosion, intergranular corrosion, filiform corrosion, etc.The following is a brief introduction of the several types of corrosion.
1. Pitting corrosion.
Also known as hole corrosion, pitting corrosion is produced on the metal tip shape, dot, the mesh form an extremely localized corrosion.aluminum(aluminum plate) in the atmosphere, water, or corrosion occurs and neutral aqueous solution, serious still can cause perforation, but may eventually stop developing corrosion hole, corrosion amount keep a limit value.Corrosion is a unique form of anodic reaction, is an autocatalytic process.
2. Galvanic corrosion
Galvanic corrosion and corrosion morphology characteristic of aluminum(aluminum plate), aluminum(aluminum plate) sp is very negative, when aluminum(aluminum plate) contact with other metals, is always in the anode aluminum(aluminum plate) corrosion speed.Galvanic corrosion is also called double metal corrosion, the severity of the corrosion is made up of two metal potential relative to location decision in a sequence.
3. Crevice corrosion
Crevice corrosion is due to the differences between gas cell function, resulting in crack corrosion speed up, and have no effect on crack outside.Crevice corrosion and alloy type has little to do, even if very corrosion resistant alloy also produces crevice corrosion.Crevice corrosion in recent years for more in-depth research, the mechanism of crack at the top of the acidic environment is a motive force of the corrosion.
4. Intergranular corrosion
Intergranular corrosion is pure aluminium is not prosperous intergranular corrosion, intergranular corrosion reason has something to do with the improper heat treatment, alloying elements or intermetallic compound along the grain boundary precipitates out, relative to the grain as a corrosion cell anode, intergranular corrosion caused by acceleration.
5. Filiform corrosion
Filiform corrosion is a film of corrosion, a worm-like development under the film, the film can make the paint film, also can make the other layer, generally does not occur under the anode oxidation membrane.