The use of steel plates on the exterior surface of buildings has a long history. In order to improve the corrosion resistance of steel plate, various coating treatments are usually carried out on the outer surface of steel plate, such as paint, enamel, zinc plating, etc. Since the 1960s, China has developed a large number of weathering steels. From 1965 to 1979, various low-alloy steels containing copper, phosphorus, rare earth and titanium were exposed to dust storms, dry industrial atmosphere, humid cities and rural areas for 15 years. The first-hand data of weathering steel are obtained.
In 1984, China formulated the Standards for Atmospheric Corrosion Steels (GB4171-84 and GB4172-84), in which the high weathering steel has three grades of 09CuCrNi-A, 09CuCrNi-B and 09CuP, and the weathering steel for welding structures has four grades of 16CuCr, 1MCuCr, 15MnCuCr and 15MnCuCr Qt.
The average corrosion depth of high-quality weathering steel in coastal environment after 16 years is about 0.1-0.2 mm, and the average corrosion depth in industrial areas and rural areas is about 0.02-0.04 mm. The test of weathering steel in WISCO shows that the average corrosion depth of weathering steel is about 0.02mm/year even in coastal cities.
Rust principle
At the initial stage of corrosion, the rust layer on the surface of weathering steel is denser than that on the surface of carbon steel, and there are relatively few cracks and cavities. Then, the carbon steel and weathering steel parts appear delamination, and there is no difference in corrosion products. The main difference lies in the role of alloy elements in the rust layer. The precipitation of copper and chromium alloy elements in the rust layer of weathering steel can resist the invasion of moisture and harmful ions in the atmosphere and prevent further corrosion of the base metal. So as to achieve the effect of atmospheric corrosion resistance!
The development of wear-resistant steel standards began in August 2007. First of all, according to the market demand and market research, on the basis of collecting domestic and foreign data, the technical route of low alloy high-strength wear-resistant steel is determined. From the scientific, practical, cost saving and resource saving point of view, low alloy high strength wear-resistant steel is an inevitable development trend. JAR360F-JAR500F export wear-resistant steel, BIS52J/53J, BIS21J, domestic market JG-JG, B24S, etc. have been developed. The main data collected are: advanced enterprise standards in Japan, Germany, Sweden, the United States and other countries, focusing on the technical conditions of wear-resistant steel in Germany, Sweden and Japan, combined with the technical conditions in China. On this basis, we will promote the maturity of domestic wear-resistant steel production enterprises as soon as possible. At present, there is no published national standard at home and abroad, so it is of great significance to formulate this standard.
The development of wear-resistant steel standards began in August 2007. First of all, according to the market demand and market research, on the basis of collecting domestic and foreign data, the technical route of low alloy high-strength wear-resistant steel is determined. From the scientific, practical, cost saving and resource saving point of view, low alloy high strength wear-resistant steel is an inevitable development trend. JAR360F-JAR500F export wear-resistant steel, BIS52J/53J, BIS21J, domestic market JG-JG, B24S, etc. have been developed. The main data collected are: advanced enterprise standards in Japan, Germany, Sweden, the United States and other countries, focusing on the technical conditions of wear-resistant steel in Germany, Sweden and Japan, combined with the technical conditions in China. On this basis, we will promote the maturity of domestic wear-resistant steel production enterprises as soon as possible. At present, there is no published national standard at home and abroad, so it is of great significance to formulate this standard.
