Steel structure anticorrosion technology comparison

Large steel structure, such as bridges, hydraulic structure, tower, chemical tank, pressure vessels and other anti-corrosion, particularly long-lasting anti-corrosion treatment (15-20 years) can have a variety of options.For example, hot-dip galvanized or aluminum technology, heavy anti-corrosion coating technology, thermal spray zinc or aluminum coating technology.Among them, the most suitable or thermal spraying aluminum or zinc coating (sealed closed layer).

If the use of harsh conditions for the steel structure of the protective service for 20 years, Zn or Al thermal spray coating life to 20 years; organic coatings with 3 years, 20 years for construction nearly 7 times, and the construction of temporary regardless of other loss caused by such enterprises, such as shutdown.Then, too, the thermal sprayed Al or Zn coated synthetic valuation is: 4~6 yuan / year m2, an average of 5 yuan / year m2; organic coating for 1.7-27 yuan / year m2, an average of 14.35 yuan / year m2, for thermal spraying technique about 3 times.

As a result of coating failure in protection period (20 years) in a construction caused a great loss.For example, the Yangtze River in Gezhouba Dam engineering of the lock gate and gate with a large Longmen crane steel structure, the steel structure of ship lift.The original paint anti-corrosion 2-3 years for an overhaul, overhaul period in each day, 20 reduction of ship traffic capacity, reduce near L200 ships navigation capacity, an annual average for 400-600 boats, causing great losses to shipping of the Yangtse river.Therefore the construction of the Three Gorges project important hydraulic gate, Huangbo River Bridge and Xialaoxi Creek Bridge required the use of thermal spraying Al or Zn coating protection.

From the comprehensive engineering using the integrated valuation, and paint coating technology and hot dip technology, thermal spraying technology has a very high ratio of performance to price.

Arc spraying technology in the fifty's has been in many countries of the steel structure manufacture and maintenance of the field have been used, but then the electric arc spraying equipment and technology level of restrictions, arc spraying is considered as a kind of high efficiency, low quality of thermal spraying method.Until six, seventy time the United States, Germany and some other developed countries on arc spraying equipment were relatively large transformation, greatly improving the coating quality, promote the arc spraying technology in steel structure manufacturing universal application, our country in the late nineteen ninties, arc spraying technology to become in recent years the most rapidly developing heat spraying technology.

For example, in recent years, Norway Dalseide &Floysand to build a total weight of 2300 tons of Norway offshore oil platform, the entire arc spraying anti-corrosion engineering using 14 G35-LD/U3 spraying equipment, spraying workers 100 3 months were sprayed with AlMg5 material 35 tons, is the world's larger thermal spraying anti-corrosion engineering model of long effect.Petrochemical Pipeline Anticorrosion were also used in thermal spraying anti-corrosion technology.

Of course, application of thermal spraying technology in construction, there exists a certain noise and dust.Steel structure for the factory production of environmental protection requirements very strict, and the field installation or old steel structure maintenance construction basically has no high requirements, but must strengthen the construction of personnel protection.

In four, long-term anti-corrosion steel structure engineering quality detection

Now, for the steel structure engineering design and construction, using quality of life tenure.In recent years, the government for the steel structure (e.g. bridge) design and manufacturing is presented in a clear life requirement.Therefore, no matter what anti-corrosion technology of steel structure for protection, in its production or maintenance of the process, must be professional and strict quality inspection and supervision.In the steel structure project of project of responsible spirit, use, construction and professional supervision party should attach great importance to this important link.

For every anticorrosion construction process, must make clear quality technical specifications.For example, steel pretreatment of blasting grade or manual pretreatment levels, anti-corrosion construction environmental requirements, paint construction procedure, proper selection of paint coating or thermal spray coating binding properties and thickness of the sample testing, sampling simulation environment corrosion test, coating appearance inspection and so on, all need the person responsible for.

Regardless of construction method, or the use of anticorrosive coating engineering, strict quality testing, must adopt a more sophisticated detection tools and equipment, but at present, many steel structure production manufacturers or engineering use to project construction how to detect coating properties, basic not very good value, some simply basic there is no testing equipment or condition.This is also a lot of steel structure service life is greatly shortened, and may cause destruction of the disaster accident is one of the main reasons.

Five, conclusion

Through the above analysis, the following conclusions can be drawn:

1 of today's society has begun to seriously long-term anti-corrosion steel structure this system engineering, it and the steel structure of the safety operation and life are closely related to the security.

2 reinforcing steel structure fabrication and maintenance of anti-corrosion construction management and supervision for engineering construction, use, and professional supervision is crucial.

3 in the steel structure design and production process, must have the professional anti-corrosion engineering and technical personnel and the participation of experts or guidance.

4 in the domestic, arc spraying technique developed in recent years is an emerging technology, has attracted more and more attention, and coating the organic combination of technology, will be more market advantage.(end)