ASTM A588/A588M — High-strength low-alloy structural steel resistant to atmospheric corrosion
Grades
Gr.A, Gr.B, Gr.K
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| Gr.A | C≤0.14, Mn≤0.90, P≤0.035, S≤0.040 | Rm 310-415 MPa, Rp0.2 ≥165 MPa, A≥27% |
| Gr.B | C≤0.17, Mn≤1.20, P≤0.035, S≤0.040 | Rm 345-450 MPa, Rp0.2 ≥185 MPa, A≥25% |
| Gr.K | C≤0.17, Mn 0.50-1.20, P≤0.030, S≤0.030, Si 0.25-0.55, Cr 0.40-0.70, Ni≤0.40, Cu 0.30-0.50, Mo 0.10-0.20, V 0.03-0.08, Nb 0.005-0.05 | Rm ≥485 MPa, Rp0.2 ≥345 MPa, A≥21%, weather resistance |
Application scope
ASTM A588/A588M specifies high-strength, low-alloy steel plates resistant to atmospheric corrosion for bridges, buildings, and other structural applications. Grades include Gr.A, Gr.B, and Gr.K. Suitable for load-bearing components requiring both welded and bolted connections. A protective rust layer is formed through alloying with copper, chromium, and nickel, allowing the exposed steel to resist atmospheric corrosion. Delivered hot-rolled, these plates possess high strength, good toughness and weldability, making them suitable for heavy-duty, long-term exposed structures.
Typical applications
It is commonly used in main load-bearing components such as bridge beams, trusses, and supports, as well as building curtain walls, exposed steel frames, and structural facades. It is also widely used in heavily corrosive environments such as railway freight cars, port cranes and loading/unloading machinery, and offshore platform ancillary facilities. Due to its resistance to atmospheric corrosion and paint-free operation, it is also suitable for landscape engineering, embankment railings, and large outdoor installations where maintenance is inconvenient.
