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Corrosion Problem Of Steel Frame

     The corrosion of steel is mainly electrochemical corrosion, steel structure in welding caused by the difference between the material, welding slag and stress will form a corrosive battery cathode and anode zone, especially steel surface rust is not complete, steel surface with a layer of iron oxide skin. Some people think that the oxide skin is not rust, in fact, this oxide is a high-temperature corrosion products, mainly the ferric oxide, it in the water containing trace salt, and steel electrode potential difference of up to 0.26 volts. In the water film, the rolling oxide peel will be used as the cathode in the pure steel to form the anode. The anode is continuously corroded, the cathode gradually expands, the rust product arches the coating, the steel structure is corroded.Steel Frame
     To do good anti-corrosion works, to achieve long-lasting anti-corrosion effect, must meet three basic requirements, namely: completes the surface treatment, the choice high performance material, achieves certain coating thickness. Surface treatment is very important, the same kind of paint, the same corrosive environment, the use of spray derusting than the manual derusting paint film Life can be extended three times times to five times times. The dirt and rust layer of the steel surface should be removed, especially the black oxidized skin formed when rolling the steel, which is the cathode of electrochemical corrosion and the root of corrosion and must be removed. The surface treatment quality should reach the Sa2 of steel surface pretreatment standard before coating. Level 5.Steel Frame
     Surface brushing Special anti-corrosion paint, is still the main means of anti-corrosion of steel structure and grid. Anti-Corrosion Paint according to the protection function can be divided into primer, middle paint and topcoat, each layer of paint has its characteristics, accountability, several layers together to form a composite coating, improve corrosion resistance, prolong service life.Steel Frame
     The primer is composed of a large amount of fine zinc powder and a small amount of film-forming base material. The electrochemical activity of zinc is higher than that of steel, and in the case of corrosion, there is a "self-sacrifice" effect, so that steel is protected. The corrosion product zinc oxide fills the void and makes the coating denser. As a anti-corrosion coating series of primer, the general thickness of 30-40 microns, too thick easy to crack and spalling.Steel Frame