ASTM A242/A242M — High-strength low-alloy weather-resistant structural steel
Grades
Type 1 (Corten-A), Type 2
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| Type 1 | C≤0.15, Mn 0.20-0.50, P 0.07-0.15, S≤0.040, Si 0.25-0.75, Cr 0.50-1.25, Ni≤0.65, Cu 0.25-0.55 | Rm ≥480 MPa, Rp0.2 ≥345 MPa, A≥18%, Weathering Index ≥6.0 |
| Type 2 | C≤0.20, Mn 0.75-1.25, P≤0.04, S≤0.05, Si 0.25-0.75, Cr 0.40-0.65, Ni 0.25-0.65, Cu 0.30-0.50, V 0.02-0.10 | Rm ≥435 MPa, Rp0.2 ≥290 MPa, A≥21%, weather resistance |
Application scope
ASTM A242/A242M specifies high-strength, low-alloy steel plates resistant to atmospheric corrosion for bridges, buildings, and other structural applications. Type 1 and Type 2 grades are available, suitable for exposed components with welded, riveted, and bolted connections. A protective rust layer formed by elements such as copper and chromium allows for exposure to resist atmospheric corrosion, reducing the need for painting. The product is delivered hot-rolled, offering high strength and good ductility, making it suitable for steel structures where weather resistance and low maintenance are critical.
Typical applications
Widely used in bridge steel structures and exposed steel structures of buildings, such as facade decoration, curtain wall frames and exposed beams and columns, as well as railway vehicle bodies, containers, power transmission towers and communication towers. With its paint-free and atmospheric corrosion-resistant characteristics, it is also commonly found in outdoor sculptures, landscape features, urban furniture and railings, and other structural and decorative components that are exposed for a long time and require a stable rust-colored texture.
