Derusting method and grade division of steel structure

2020-05-10 20:06:20 Share

In the design of steel structure engineering, a large amount of steel is required, but if the steel used in construction is rusted a lot, it will greatly shorten the service life. It is also a challenge to personal safety. The collapse of the house is not uncommon. In recent years, it has been paid more and more attention. Today Fangtong Steel Structure will teach you some ways to remove rust!
1. Pickling to remove rust It is to immerse the steel component to be painted in the acid tank, and use the acid to remove the oil stain and rust on the surface of the component. The pickling process is also highly efficient and the rust removal is relatively thorough, but after pickling, the component must be washed with hot water or clean water. If there is residual acid, the rust of the component will be more severe.
2. Manual rust removal is the manual use of some relatively simple tools, such as scraper, grinding wheel, abrasive cloth, wire brush and other tools to remove rust on steel components. This method has low working efficiency, poor working conditions and incomplete rust removal.
3. Sand blasting It uses the pressure of compressed air to continuously hit the surface of the steel member with quartz sand or iron sand to clean up the rust, oil stains and other debris on the steel surface, revealing the true nature of the metal steel. method. This method has high efficiency and thorough rust removal, and is a relatively advanced rust removal process.
How to divide the steel structure rust grade?
Class A: steel surface covered with oxide scale and almost no rust
Class B: The steel surface has corroded and part of the scale has been peeled off
Class C: the scale has been peeled off due to corrosion or can be scraped off, and there is a small amount of pitting on the steel surface
Class D: The steel surface has been completely peeled off due to rust, and the steel surface where pitting corrosion has generally occurred

Construction methods	Characteristics of Coatings Applicable			Coating	Use of tools or equipment	Main strengths and weaknesses
Construction methods	Drying speed	Viscosity	Variety	Coating	Use of tools or equipment	Main strengths and weaknesses
Brush painting	Dryness is slow	Small plastic	Oily paint Phenolic paint Alkyd paint	General components and buildings, plumbing, etc.	Brush	Less investment, simple construction method, suitable for the shape and size of the coating; the disadvantages are poor decoration, low construction efficiency
Hand roll coating	Dryness is slow	Small plastic	Oily paint Phenolic paint Alkyd paint	Components and management of general large planes, etc.	Roller	Less investment, simple construction method, suitable for large area coating; disadvantages of the same brush painting method
Dip coating	Proper drying, good leveling, moderate drying speed	Good thixotropy	synthetic resin coatings	Small components, equipment and mechanical components	Lacquer tank, centrifuge and vacuum equipment	The equipment investment is less, the construction method is simple, the paint loss is less, is suitable for the construction complex component; the disadvantage is that the flow flatness is not very good, has the flow hanging phenomenon, the pollution phenomenon, the solvent is volatile
Air spraying	Volatile quickly and dry moderately	Low viscosity	Nitro paint, rubber paint, building vinyl paint, polyurethane paint, etc.	Large components and equipment and piping	Spray gun, air compressor, oil/water separator, etc.	The equipment investment is small, the construction method is more complex, the construction efficiency is higher than the painting method; the disadvantage is that the consumption dose is large, the pollution phenomenon is easy to cause the fire
Fog spray	Paint with only high boiling point solvent	High nonvolatile, thixotropy	Raw and high non-volatile coatings	Large steel structures, bridges, pipelines, vehicles, ships, etc.	High pressure airless spray gun, air compressor, etc.	The equipment investment is big, the construction method is more complex, the efficiency is higher than the air spraying method, can obtain the thick coating; the disadvantage is also to lose part of the coating, the decoration is poor

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