Anticorrosive coating to electric furnace process of application
The functions of hot-dip galvanized and aluminum anticorrosive coating mainly include the following aspects:
1. Application of anti-atmospheric corrosion coating
Outdoor steel structures such as steel factory buildings, steel box girder Bridges, TV towers, building antennas, feed substations, steel lamp posts, etc. These steel components are exposed to the atmosphere for a long time, and are exposed to climate change, sun and rain. Their surfaces are rapidly oxidized, generating a layer of iron trioxide, which seriously affects the strength and service life of steel structures. In order to prevent the oxidation of the surface of steel structure, generally used in the past paint protection, its anticorrosive life is generally in 3-5 years, so the need for regular maintenance, maintenance, the common method is copying shovel paint, cost a lot of manpower and material resources. The surface of steel structure is protected by zinc spraying and aluminum spraying. The anti-corrosion life can be more than 30 years without maintenance. If the zinc aluminum coating and paint closure, it is longer anti - corrosion life.
Only after spraying zinc and aluminum on the surface of the steel structure normal furnace can it play the anodic protection function, so as to achieve the purpose of long-term anti-corrosion of steel structure. Therefore, many major national projects and municipal projects have been designated to adopt this process. Such as: the Yangtze River three Gorges permanent gate, Shanghai Oriental Pearl TV Tower, Yangpu bridge main guard pole, Guangzhou inner ring elevated steel beam, Shanghai Securities Building steel structure antenna, Pudong Airport Road joint ditch gas explosion pipeline, Shanghai Nanqiao 500mw transformer substation and so on, to ensure the major projects of the century.
2. Water-resistant coating for electric furnace
The steel sluice gate is the main steel structure that controls the water flow in hydroelectric power stations and reservoirs. It is partially submerged for a long time and its surface is eroded by microorganisms (such as the absorption of scorpions and the acidity of their excrement). The other part is exposed to the atmosphere for a long time, especially the waterline part, which is impacted by surfing and floating objects on the water surface, and affected by high tide and low tide at the same time, which makes the surface of this part of the steel structure often alternate between wet and dry, and is especially prone to rust. Now using zinc spray wire, spray aluminum process, greatly improve the corrosion resistance of the steel gate, than the original paint process anti-corrosion life increased 5~6 times.
3. Comparison of properties between zinc and aluminum spraying processes and similar processes (hot dip galvanizing process)
1, roller furnace electric hot galvanizing process pretreatment with pickling, phosphating process, the workpiece surface will have acid, alkali liquor residue, leaving a potential corrosion, so that the hot galvanized layer is easy to fall off. The pretreatment of zinc and aluminum spraying process adopts sand blasting process, so the surface of the workpiece is very clean and rough, the surface of zinc spraying and aluminum spraying will not produce corrosion from inside to outside, so there will be no zinc layer falling off phenomenon.
2. The hot-dip galvanizing process has a certain temperature, about 440℃, so the workpiece will be deformed after hot plating; Zinc and aluminum spraying process spraying temperature is very low, the surface temperature of the workpiece < 80℃, so the workpiece is not deformed.
3. Hot-dip galvanizing process is adopted, and the workpiece is limited by the length × width × height of the plating bath; And the use of zinc spray, spray aluminum process is not limited to the workpiece.
4. Hot-dip galvanizing process is adopted, and on-site repair problems still exist in the electric furnace. In the process of welding seam, loading and unloading, transportation, repair can only use paint, so as to create a process breach. If using zinc spray, aluminum spray process, then the site can be used zinc spray, aluminum spray repair, to avoid the process breakthrough.
5. As the pretreatment of hot dip galvanizing process adopts pickling and phosphating, the surface of the workpiece has no roughness and the coating adhesion is poor. The pretreatment of zinc and aluminum spraying process USES sand blasting, Sa≥2.5 grade, so the surface of the workpiece has rough roughness, coating adhesion is good. Tensile strength ≥0.6kg/mm2.
6, hot dip galvanizing process is very serious to water pollution, environmental protection issues are very prominent, so hot spray zinc, spray aluminum process in the more extensive.
On 2018-08-08 11:45:46
