Corrosion resistance of low alloy steel

Corrosion resistance of low alloy steel

When using low alloy steel, we are eager to take advantage of its high strength and thin cross section, this is not only to save weight but also as far as possible considering the economic. However, we must give full consideration to the factors of corrosion of steel section, the thinner the more attention should be paid to corrosion. Any steel structure anticorrosion is generally through the method of surface in the appropriate preparation coated anticorrosive coating and the coating to protect to achieve. Some low alloy high strength steel has good corrosion resistance, it can not only improve the coating effect, and to take appropriate preventive measures in some cases also can be exposed in the uncoated condition used in the atmosphere. High strength low alloy steel atmospheric corrosion properties along with the change of corrosion on composition and content of alloy elements in the maximum. To improve the atmospheric corrosion resistance of copper, phosphorus element is silicon, chromium, nickel and molybdenum.

Some low alloy high strength steel has excellent resistance to atmospheric corrosion leads to the formation of the new concept of building, bridge structure design, the structure is exposed component selection of low alloy high strength steel to be construction. Under normal atmospheric exposure conditions, bare steel to form a dense protective film in the first few months of atmospheric corrosion. Sometimes architects use steel structure exposed because of hope to get the atmospheric oxidation of steel surface and uniform appearance, and sometimes in order to save coated so as to achieve the economic purpose. The use of these high strength low alloy steel in the bare state, alloy steel design must consider the surface not steel long is wet, but should also pay special attention to unusual atmospheric conditions, to ensure that the corrosion rate of the steel under the condition is allowed. For example, in the strong chemical or industrial flue gas condition is obviously not suitable. In order to verify whether can use the exposed steel structure in certain circumstances, it is necessary to determine the atmospheric environment, and even the need for bare test.