Composition and Properties of Weathering Steel 09CuPCrNi-A Low Alloy High Strength Steel
I. Basic Information
09CuPCrNi-A belongs to weatherproof steel. Through alloying of Cu, Mn, Si and Al, and simply adjusting the element content of common low carbon steel (Q235 steel), economic weatherproof steel with good atmospheric corrosion resistance and comprehensive mechanical properties can be produced without changing the production process of Q235 steel. It is mainly used for steel structures such as railways, vehicles, bridges and towers which are exposed to the atmosphere for a long time.
Brand 09CuPCrNi-A
Standard Q/ASB 274-2005 Hot Strip and Steel Strip for Atmospheric Corrosion Resistant Structures
Material Class Low Alloy High Strength Steel
Hot rolled products
Usage: Structural steel, building and bridge, railway vehicle
This product is hot rolled steel sheet and strip with thickness less than 14mm for atmospheric corrosion resistance. It is used to manufacture railway vehicles, buildings, towers and other structural parts.
2. Chemical Constituents (wt%)
C. Si Mn P S Ni Cr Cu
0.12 0.25-0.75 0.2-0.5 0.07-0.12 < 0.02 0.12-0.65 0.3-1.25 0.25-0.5
Composition Note: Nb, V, Ti and other trace elements are allowed to be added.
3. Basic mechanical properties
Brand, Delivery Status, ReL
MPa Rm
MPa
A (%) Impact Temperature () Akv
(J) Bending diameter, bending angle (C)
Performance description
09CuPCrNi-A (< 6) Hot Rolling (>355 (>490) (>24-40)
More than 21
portrait
1A
180. Tensile test transverse; ReL/Rm < 0.75; Delivery status: hot rolling, controlled rolling
09CuPCrNi-A (> 6-14) Hot Rolled (> 355 (> 490 (> 24-40)
More than 21
portrait
2A
180. Tensile test transverse; ReL/Rm < 0.75; Delivery status: hot rolling, controlled rolling
IV. THE DEVELOPMENT OF WEATHER RESISTANT STEEL
Since the beginning of the 20th century, weathering steels have been deeply studied in the United States, Germany, Britain and Japan. As early as 1900, European and American scientists discovered that copper can improve the corrosion resistance of steel in the atmosphere. In 1916, the American Society of Experiments and Materials (ASTM) began the study of atmospheric corrosion. C. P. Larrabee et al. accumulated atmospheric corrosion data, summarized the corrosion law and discussed the corrosion mechanism. In the 1930s, U. S. Steel first developed a corrosion-resistant high strength low alloy steel with copper, Corten steel, which was directly used in buildings and bridges without painting in the 1960s. Among them, Corten A series steels with high phosphorus, copper+chromium and nickel and Corten B series steels with chromium, manganese and copper alloying as the main alloying steels were most widely used. Series steel. This kind of weathering steel is also widely used in Europe and Japan. At present, weatherproof steel has gradually been widely used as common steel in foreign countries, and the development, use and design and construction of steel grades are also specified in detail.
5. Manufacturing Technology of Weatherproof Steel
Weatherproof steels generally adopt refining-smelting (converter, electric furnace-microalloying treatment-argon blowing-LF refining-low superheat continuous casting (feeding rare earth wire) -controlled rolling and cooling process. During smelting, scrap steel is added into the furnace together with burden, and is smelted according to conventional process. After tapping, deoxidizer and alloy are added. After argon blowing treatment, molten steel is casted immediately. After argon blowing, the molten steel is casted into slab by continuous caster. Due to the addition of rare earth elements in the steel, the weathering steel is purified and the inclusion content is greatly reduced.
Function and Significance of Weatherproof Steel
Corrosion, especially in the atmosphere, is one of the main forms of destruction of iron and steel materials. About one-sixth of the world's steel output is corroded every year. According to the statistics of relevant departments, the direct economic losses caused by steel corrosion in China exceed 10 billion yuan every year, and the cost of anti-rust measures such as polishing and painting accounted for a considerable proportion of the total cost of project investment. Therefore, it is self-evident that it is important to prevent or slow down the corrosion of iron and steel materials in the atmosphere. Stainless steel can effectively prevent corrosion, but the cost of large-scale use is too high to bear, and the mechanical properties and welding properties of stainless steel are difficult to meet the needs of various projects. Weatherproof steel came into being under such a background. Weatherproof steel is atmospheric corrosion resistant steel, which is characterized by adding a small amount of alloying elements such as Cu, P, Cr and Ni into the steel, so that a dense amorphous spinel oxide layer about 50-100 um thick can be formed between the rust layer and the matrix metal. Because of the existence of this dense oxide film, oxygen and water in the atmosphere are prevented from infiltrating into the steel matrix, and the development of corrosion into the steel material is slowed down, thus greatly improving the atmospheric corrosion resistance of the steel material.
7. Use of Weatherproof Steel
Weatherproof steel materials are widely used in construction, bridge, shipbuilding, vehicle and other fields. The use of steel in complex environmental conditions requires a variety of steel applications, such as rust resistance of railway vehicles, corrosion of steel for ship hulls and offshore oil platforms. Raw water used in household appliances and tableware is less corrosive due to its use at room temperature, but it is more corrosive in the surrounding environment of ship hulls and offshore buildings, and more corrosive in high temperature steam and generator environments. Petrochemical plants are also highly corrosive due to their high temperature acidic environment and salty environment for automobiles. Because the corrosion phenomenon in the environment is very common and the requirements for corrosion-resistant materials are different, it is self-evident that it is important to develop iron and steel products to meet the environmental requirements. - The classification of corrosion-resistant steel in China is mainly based on the surrounding environment and the corrosive medium. It can be basically divided into weather-resistant steel and sulfuric acid dew point corrosion-resistant steel. Weather-resistant steel includes atmospheric corrosion-resistant steel and marine corrosion-resistant steel. Since the 1960s, scientific researchers have been working in succession.A series of exposure tests have been carried out in different environments, such as dry sand, industrial atmosphere, low-lying wetlands and the East China Sea, and foreign technologies have been imitated. Since the 1980s, when it was listed in the national key technical projects, it has gradually come out of the road with its own characteristics. At present, there are two main series of atmospheric corrosion resistant steels: Cu-P-Re and Cu-P-Ni-Cr. The domestic low-alloy seawater corrosion resistant steels are basically imported foreign mature grades, such as Mariloy-G400A/S of Baosteel. 490A; Co-TenB and 10CrMoAl of Wugang, etc., the research of sulfuric acid corrosion resistant steel started late.
8. Service life
Weatherproof steel materials can be used for more than 30 years without any anticorrosive treatment, which is eight times longer than that of ordinary steel.
Wang Shansheng: 0371-63371868 15027010720 QQ: 3321202579 Fax: 0371-8881020