Methods for preventing corrosion of steel
Methods for preventing corrosion of steel productsAccording to statistics every year in the world because of corrosion and scrap metal manufactures weight equivalent to about 1/3 metal production,a, E, even considering in two-thirds of the corrosion of scrap metal can be recycled, there is equivalent to the annual output is about a year, one of the metal loss due to corrosion. Besides, the value of corrosion damage can't be just to gauge how many tons of metal lost, calculate, because, corrode the value of scrap metal manufactures often are much higher than the value of the metal itself. Therefore, metal, anti-corrosion problem has very important economic significance.
Steel is the most important and widely used structural material and functional material in human production and life.In the last century, the technology assessment agency has proposed the idea of "three a third material development in the future: material performance, improve, a third by surface technology: a third by strengthening technology; One third depends on the development of non-metallic materials. It is said here that "performance improvement", an important aspect, is the improvement of material corrosion resistance.For a long time, people have fought against steel corrosion, creating many effective ways to prevent steel corrosion. These methods can be summarized in two categories: one is alloy corrosion protection method; The other is surface coating antiseptic method. The alloy anticorrosion method belongs to the category of strengthening technology, and the coating anticorrosion method belongs to the category of surface technology.
The anti-corrosion method of alloy is to add chromium, nickel and other alloy elements into steel to make various kinds of stainless steel, its anti-corrosion ability is greatly improved than ordinary steel, and the corrosion process is greatly slowed down.The method of coating anticorrosion is divided into: non-metal cladding method, metal cladding method, and the combination of the two methods.For example, paint the surface of steel equipment, which is non-metal coating anti-corrosion treatment; Zinc plating on the surface of steel, which is metal, coating corrosion treatment; The steel strip is coated with zinc and then painted to make a color coating plate, which is a combination of metal coating and non-metal coating.
Metal coating antiseptic method, is in the steel surface coated with other types of metal. The methods of metal plating mainly include: cold plating, method (including electroplating method, chemical plating method), hot-dip plating method (short for hot plating method), gas plating method (i.e. vacuum evaporation plating method), they are respectively!It is carried out in the aqueous state of metal compounds, the liquid state of metal and the gaseous state of metal. In addition, there are infiltration, coating, spray plating and other metal plating methods.It is worth noting that the anti-corrosion treatment of thin steel plate occupies a particularly important position in anti-corrosion treatment of steel. This is because, on the one hand, the thin steel plate production process is complex, the process is difficult, the cost is high, the value is high; On the other hand, due to its thickness, thin, larger than the surface area, it is more likely to be scrapped after corrosion. Therefore, the necessity and importance of anti-corrosion treatment of thin steel plate are obvious, especially prominent..