Weathering steel plate is a specialty carbon steel plate with excellent corrosion resistance and a unique color change, forming a dense, rust-red oxide film in natural environments.
About Weathering Steel Plate
Weathering steel plate, also known as atmospheric corrosion-resistant steel plate or Corten steel plates, is a specialty steel material that lies between ordinary carbon steel plate and stainless steel sheet. It is made by adding small amounts of alloying elements such as copper, phosphorus, chromium, and nickel to ordinary steel to enhance its corrosion resistance. Under natural conditions, a dense, rust-red oxide film gradually forms on the surface of the weathering alloy steel plate, preventing further corrosion and thus extending its service life.
Features of Weathering Steel Plate
1. Excellent Corrosion Resistance: Corrosion-resistant steel plate gradually forms a dense, rust-red oxide film in natural environments. This film effectively resists corrosive media in the atmosphere, protecting the steel plate from further corrosion.
2. Unique Color Change: Over time and in response to environmental changes, the surface of weathering steel gradually develops different colors, from bluish-black to light brown to rust-red. This unique color change gives Corten steel plate a high aesthetic value in architectural and landscape design.
3. Environmentally Friendly and Sustainable: Corrosion resistant steel plate is an environmentally sustainable building material. Its production process has minimal environmental impact, and it requires no painting or other anti-corrosion treatments during use, reducing maintenance costs and environmental impact.
Main Types of Weathering Steel Sheets
Depending on their composition and performance, Corten steel plates are primarily categorized into several types, including Q235NHB corten steel sheet, Q345NHB corrosion resistant steel sheets, and SPA-H corten steel sheets. While maintaining basic weathering resistance, these types of weathering alloy steel sheet each offer unique characteristics suitable for different applications.
Weathering Steel Sheet Standards and Materials in Different Countries and Regions
GB Standard Grades:
Q235NH
Q355NH
ASTM Standard Grades:
SPA-H: Container-specific weathering steel grade.
Corten-A/B: Weathering steel according to ASTM A588.
09CuPCrNi-A: Ministry of Railways standard weathering steel grade, according to TB 1979.
EN Standard Grades (EN10025-5:2004):
S355J0W
S355J2W
S355K2W
S355J0WP
S355J2WP
JIS Standard Grades (JIS G3114-2004):
SMA400AW/BW/CW
SAM490AW/BW/CW
SAM570W/P
Q235NH: This is a commonly used weathering steel grade in China, offering excellent atmospheric corrosion resistance and suitable for the manufacture of structural components exposed to long-term outdoor conditions, such as vehicles, bridges, and towers.
Q355NH: Compared to Q235NH, Q355NH has a higher yield strength, exceeding 355 MPa, resulting in improved load-bearing capacity and deformation resistance. It is also suitable for outdoor structures subject to heavy loads.
Q355GNH: This is another highly weather-resistant grade, offering similar mechanical and weathering properties to Q355NH, but with a greater emphasis on corrosion resistance in specific environments.
SPA-H: This is an internationally recognized grade of corten steel for containers and the most widely used grade both domestically and internationally. It contains specific alloying elements that enable it to form a dense oxide film in natural environments, thereby resisting atmospheric corrosion.
09CuPCrNi-A: This corrosion resistant steel is produced according to the Ministry of Railways standard (TB 1979). It offers excellent atmospheric corrosion resistance and weldability, making it suitable for structural components such as railway vehicles and bridges.
Q345NQR2: This weathering steel also offers high strength and excellent weather resistance, making it suitable for large structural components exposed to long-term outdoor conditions, such as building curtain walls and sculptures.
Other weathering alloy steel grades include ASTM A588, Corten A, Corten B, S355J0W and S355J2W specified in the European standard EN10025-5:2004, and SMA400AW/BW/CW and SAM490AW/BW/CW specified in the Japanese standard JIS G3114-2004. Each of these weathering alloy steel grades has its own unique characteristics, making them suitable for different environments and applications.
Applications of weathering steel plate
Due to its unique corrosion resistance and color change, weathering steel plate is widely used in architecture, landscaping, highway bridges, and other fields. In the construction industry, weathering steel is commonly used for exterior walls, roofs, and decorative components. In landscape architecture, it can be processed into various shapes through laser cutting machine or welding, resulting in sculptures, feature walls, and other structures. In highway and bridge construction, weathering steel is favored for its excellent corrosion resistance.
Differences Between Weathering Steel and Ordinary Steel
Compared to ordinary steel, weathering alloy steel offers superior corrosion resistance and unique color variations. Ordinary steel is susceptible to rust and corrosion in the natural environment, requiring regular painting or other anti-corrosion treatments. Corrosion-resistant steel, on the other hand, naturally forms a protective oxide film, reducing or eliminating subsequent maintenance. Furthermore, the color variations of weathering steel add to its unique aesthetic value.
