ASTM A242/A242M — Weathering steel profiles
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 resistant to atmospheric corrosion for bridges, buildings, and other structural applications, in the form of structural sections. It includes Type 1 and Type 2 grades and is suitable for load-bearing sections requiring welding, riveting, and bolting. The use of elements such as copper and chromium to form a dense rust layer makes exposed angle steel, channel steel, and I-beams corrosion-resistant and reduces the need for painting. The products are delivered hot-rolled, have high strength, and are suitable for exposed, low-maintenance structural frameworks.
Typical applications
Primarily used in bridge steel structures and exposed steel structures of buildings for beams, columns, supports, and connecting profiles, such as angle steel, channel steel, and I-beams, as well as for transmission towers, communication towers, and outdoor sculptures and landscape frameworks. With its paint-free and atmospheric corrosion-resistant properties, it is suitable for steel structures that are exposed for long periods, require inconvenient maintenance, and require a stable rust-colored finish.
