The common corrosion forms of airport chairs, we usealuminum alloy as an example, the occurrence of the corroded conditions havesuch five conditions:
1. Point corrosion: point corrosion (hole corrosion), whichis a localized corrosion form of needle, point and hole in metal.
Point corrosion is a unique form of anode reaction, is akind of autocatalytic process, is the corrosion process caused by pittingcorrosion hole condition, if there is corrosive medium (CL - F -, etc.),promote the reaction of (CU2 + ZN2 +, etc.), is to promote and to maintain thecorrosion to continue.
2. Uniform corrosion:
Aluminum in phosphoric acid and sodium hydroxide solution,its oxidation film dissolve, uniform corrosion,dissolution rate is uniform, solution temperature, solution concentration,promote corrosion of aluminum.
3. Crevice corrosion:
Crevice corrosion is a local corrosion. Metal parts inelectrolytic solution, because the metal and metal, nonmetal and metal formedbetween aperture, paragraph it is enough to make media immersion and the mediais in a state of stagnation, makes the crack phenomenon known as the crevicecorrosion of the internal corrosion intensifies.
4, intergranular corrosion, due to the grain as the cathodematerial, and grain boundary as the anode, usually in the uniform corrosionCondition, grain boundary corrosion is still greater than grain, if underspecial circumstances, and relatively less material grain boundary corrosionresistance elements, the phenomenon of intercrystalline corrosion will happen.
5. Stress corrosion cracking: the SCC of aluminum alloy wasdiscovered in the early 1930s. The characteristic is that the formation ofcorrosion is a mechanical fracture that can be developed along the grainboundary or through the decay of the crystal. Because the fissure is extendedinside the metal, the strength of the metal structure will be greatly reduced,and sudden damage will occur.
Several corrosion status not only at the airport, ofcourse, this chair above, any items on aluminum alloys will possible situation,because very few metal in storage for a long time not corrosion.