Today's society, as systems engineering, steel structure is directly related to the safe operation and life of long-term preservation project is to use side by engineering, design and construction side side, and many other attention. Proved: to strengthen the process of steel production and maintenance of anti-corrosion construction management and supervision, using the side of the project, the construction side and the supervision side, it is of crucial importance; in steel design and production process, must have a professional corrosion engineering and technical personnel and experts to participate or guidance. In recent years, composite arc spraying long-lasting anti-corrosion technology is increasingly in the promotion and application of steel production.
So far, the corrosion of steel to the world economy is a huge loss. Some industrial countries, according to statistics, every year due to corrosion of steel caused economic losses of about 2% of national GDP to 4%. The United States in 1975 due to corrosion caused economic losses of about $ 70 billion, accounting for the year to 4.2% of GDP in 1982 up to $ 126 billion; corrosion loss of the British in 1969 ? 1.365 billion, accounting for 3.5 of GDP %; corrosion losses in 1976, Japan $ 9.2 billion, representing 1.8% of GDP; According to our 1995 statistics, the corrosion losses of up to more than 150 billion yuan, accounting for 4% of GDP. Currently, the worldwide each year due to corrosion of steel has caused economic losses of up to hundreds of billions of dollars.
Moreover, the steel due to corrosion caused by accidents endanger the safe operation of the structure. Frequent catastrophic accidents caused by corrosion, very serious consequences, especially under large welded steel and steel under stress conditions, due to stress, corrosion will be greatly accelerated, which happened the so-called stress corrosion problems in steel structural damage is extremely common. For example, the bridge structure or roof structure of high altitude because of severe corrosion problems, must be rebuilt, otherwise it will cause serious consequences, of course, the economic investment is considerable, and now, the domestic construction of a large steel bridge, will cost at least hundreds of millions of yuan. Osaka Japanese subway in 1970 due to corrosion of the pipeline break, causing a gas explosion, 75 passengers died on the spot. A city in China in 1979 liquefied petroleum gas tank explosion and fire due to corrosion, dozens of casualties, direct economic losses reached 6.3 million. And, due to accidents caused by downtime, shutdown caused by the indirect economic losses may exceed the direct economic losses of several times.
Because of this, the use of steel anti-corrosion technology, especially the long-term preservation of new technology becomes important priority. If the steel can 15 to 50 years of maintenance-free, then use the side will save a lot of maintenance funding, and greatly improve the safety and life of steel.
Now, for the design and construction of steel structure, the quality of tenure are used. In recent years, the Government steel (such as bridges) and make a clear design and manufacture of life requirements. Therefore, no matter what steel corrosion protection technology for processing in its production or maintenance process, the need for professional testing and strict quality supervision. Charge of works in line with the spirit of the steel, engineering, consumer, construction side and professional side should attach great importance to supervision of this important aspect.
For every anti-corrosion construction process, we must make clear the quality of the technical specifications. For example, when blasting steel pre-treatment level or manual pre-treatment levels, anti-corrosion construction of environmental requirements, paint, construction process planning, the right choice of paint coating or a combination of thermal spray coating performance and the thickness sampling site, sampling for simulated environment corrosion test, visual inspection of the coating, etc., all require the person responsible.
Whether the construction side, or engineering use side, anti-corrosion coating on the strict quality inspection, it must adopt a more sophisticated testing methods and equipment, and in the present, many manufacturers of steel production, or use the side of the construction works, how to detect anti-corrosion coating performance, little attention very well, some simply did not test equipment or conditions. This is also a lot of steel service life expectancy shortened, and may cause damage to one of the major disaster occurred.
