Weathering steel, that is, atmospheric corrosion resistant steel, is a low-alloy steel series between ordinary steel and stainless steel. The weathering plate is made of ordinary carbon steel with a small amount of corrosion resistant elements such as copper and nickel added. The weathering resistance is 2~8 times of ordinary carbon steel, and the coating resistance is 1.5~10 times of ordinary carbon steel. Therefore, "weathering steel" is often referred to as "Corten Steel" in English. Unlike stainless steel, which is completely rust free, weathering steel is only oxidized on the surface and will not go deep into the interior. It has anti-corrosion characteristics like copper or aluminum.
1-Why can weathering steel rust without corrosion?
Weathering steel is different from ordinary steel. At the beginning, it will rust on the surface like ordinary steel. Due to its high degree of alloying, this process is even faster than ordinary steel. However, due to the more complex lattice inside the weathering steel, a dark black dense rust layer will grow under the loose rust on the surface. In this uniform dense rust layer, nickel atoms replace some of the iron atoms, making the rust layer cationic selective and resistant to the penetration of corrosive anions.
It is this dense rust layer that makes the surface of weathering steel rusted, but the interior will not be rusted. In fact, as long as we carefully distinguish, we can see that the surface of weathering steel is different from ordinary rust: the rust of weathering steel is uniform and dense, and the surface close to the steel protects the steel; Rust, on the other hand, is mottled and porous, causing it to fall off easily.
2-Manufacturing Process of Weathering Steel Plate
The weathering steel plate generally adopts the process route of fine material feeding smelting (converter, electric furnace microalloying argon blowing LF refining low superheat continuous casting (feeding rare earth wire) controlled rolling and controlled cooling. During smelting, the scrap steel is added to the furnace along with the furnace material, and is smelted according to the conventional process. After tapping, deoxidizers and alloys are added. After argon blowing treatment, the molten steel is immediately cast. The molten steel after argon blowing temperature adjustment is cast into slabs through a continuous casting machine. Due to the addition of rare earth elements in the steel, the weathering steel plate is purified and the inclusion content is greatly reduced.
3-Use of Weathering Steel
Weathering steel is mainly used for railway, vehicle, bridge, tower, photovoltaic, high-speed engineering and other steel structures exposed to the atmosphere for a long time. It can also be used to manufacture structural components such as containers, railway vehicles, oil derricks, harbor buildings, oil production platforms, and containers for sulfur-containing corrosive media in chemical and petroleum equipment. In addition, due to its unique appearance, weathering steel is also often used for public art, outdoor sculpture and building exterior decoration.
4-Advantages of Weathering Steel
One-Green and environmentally friendly
Without the need for initial coating, the use of fireproof coatings and coatings can be reduced, thereby reducing pollution, shortening construction period, reducing costs, and reducing maintenance. It is an economic steel with "green environmental protection" and sustainable development;
Two-High visual expression
The weather resistant steel plate will change with time, and its color brightness and saturation are higher than those of general building materials, so it is easier to highlight in the background of garden green plants;
Three-Strong shaping power
Weathering steel plate is easy to shape into a variety of shapes, and can maintain excellent integrity;
Four-Good spatial boundary force
The space is clearly and accurately separated by using very thin weather resistant steel plate to make the site simple and bright.
5-Disadvantages of Weathering Steel
One-Corrosion of welding points
The oxidation rate of the welding point must be the same as other materials used, which requires special welding materials and techniques;
Two-Water accumulation corrosion
Weather resistant steel plate is not stainless steel plate. If there is water in the concave of weathering steel, the corrosion rate will be faster, so drainage must be done well;
Three-Salt rich air environment
The weathering steel plate is sensitive to the salt rich air environment, in which the surface protective film may not prevent further oxidation inside;
Four- Color fading
The rust layer on the surface of the weathering steel plate can make the surface of objects near it rusty;
Five- Maintenance processing
Need to handle rust prevention and various patterns and colors, and many treatments are relatively expensive.
The common Corten Steel Grades are: ASTM A242, ASTM A606, ASTM A588 & ASTM A847. If you have the buying needs of Weathering Steel plates, Corten Steel Sheets, JINDALAI professional team will give you the best the solution for your projects. Contact us now! Tel: +86 18864971774
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Post time: Jun-14-2023