Introduction of several common corrosion types on industrial aluminum profiles


Release time:

2015-10-17

Generally speaking, the basic types of industrial aluminum profile aluminum are somewhat corrosion, galvanic corrosion, crevice corrosion, intergranular corrosion, filiform corrosion, etc. The following is a brief introduction to these types of corrosion. One. Pitting corrosion, also known as pitting corrosion, is a kind of extremely local corrosion form that produces needle tip, dot and hole on metal. Aluminum in the atmosphere, fresh water, or neutral water solution will occur pitting corrosion, serious can also lead to perforation, but the corrosion hole may eventually stop developing, the amount of corrosion to maintain a limit value. Pitting corrosion, a unique form of anodic reaction, is an autocatalytic process. II. Galvanic corrosion is also a characteristic corrosion form of aluminum, the natural potential of aluminum is very negative, when aluminum is in contact with other metals, aluminum is always in the anode to accelerate its corrosion. Galvanic corrosion, also known as bimetallic corrosion, is determined by the relative position of the two metal potential series. Three. Crevice corrosion Crevice corrosion is due to the differential gas battery effect, resulting in accelerated corrosion in the crevice, while the crevice has no effect. Crevice corrosion has little to do with the type of alloy, and even very corrosion-resistant alloys can produce crevice corrosion. In recent years, the mechanism of crevice corrosion has been further studied, and the acidic environment at the top of the crevice is the driving force of corrosion. Four. Intercrystalline corrosion intercrystalline corrosion refers to pure aluminum is not flourishing intercrystalline corrosion, the cause of intercrystalline corrosion is related to improper heat treatment, alloying elements or intermetallic compounds along the grain boundary precipitation precipitation, relative to the grain is the anode to form a corrosion battery, causing intercrystalline corrosion acceleration. Five. Filiform corrosion Filiform corrosion is a kind of under-film corrosion, which develops under the film in a worm shape. This film can make the paint film or other layers, which generally does not occur under the anodic oxide film.

Generally speaking, the basic types of industrial aluminum profiles are somewhat corrosion, galvanic corrosion, crevice corrosion, intergranular corrosion, filiform corrosion, etc. The following is a brief introduction to these types of corrosion.
One. Pitting corrosion
Pitting corrosion, also known as hole corrosion, is a very local corrosion form that produces needle tip, dot and hole on metal. Aluminum in the atmosphere, fresh water, or neutral water solution will occur pitting corrosion, serious can also lead to perforation, but the corrosion hole may eventually stop developing, the amount of corrosion to maintain a limit value. Pitting corrosion, a unique form of anodic reaction, is an autocatalytic process.
Two. Galvanic corrosion
Galvanic corrosion is also a characteristic corrosion form of aluminum. The natural potential of aluminum is very negative. When aluminum is in contact with other metals, aluminum is always at the anode to accelerate its corrosion. Galvanic corrosion, also known as bimetallic corrosion, is determined by the relative position of the two metal potential series.
Three. Crevice corrosion
Crevice corrosion is due to the differential gas battery effect, resulting in accelerated corrosion in the crevice, while there is no effect outside the crevice. Crevice corrosion has little to do with the type of alloy, and even very corrosion-resistant alloys can produce crevice corrosion. In recent years, the mechanism of crevice corrosion has been further studied, and the acidic environment at the top of the crevice is the driving force of corrosion.
Four. Intercrystalline corrosion
intercrystalline corrosion refers to pure aluminum does not thrive intercrystalline corrosion, the cause of intercrystalline corrosion is related to improper heat treatment, alloying elements or intermetallic compounds precipitate along the grain boundary, relative to the grain is the anode to form a corrosion battery, causing intercrystalline corrosion acceleration.
Five. Filiform corrosion
Filiform corrosion is a kind of under-film corrosion, which develops under the film in a worm shape. This film can make the paint film or other layers, which generally does not occur under the anodic oxide film.