ASTM A572/A572M — High-strength low-alloy structural steel profiles
Grades
Gr.42, Gr.50, Gr.55, Gr.60, Gr.65 (W型/S型/C型/L型等)
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| Gr.42 | C≤0.21, Mn≤1.35, P≤0.040, S≤0.050, Nb+V 0.01-0.15 | Rm ≥415 MPa, Rp0.2 ≥290 MPa, A≥24% |
| Gr.50 | C≤0.23, Mn≤1.35, P≤0.040, S≤0.050, Nb+V 0.01-0.15 | Rm ≥450 MPa, Rp0.2 ≥345 MPa, A≥21% |
| Gr.55 | C≤0.25, Mn≤1.35, P≤0.040, S≤0.050, Nb+V 0.01-0.15 | Rm ≥485 MPa, Rp0.2 ≥380 MPa, A≥20% |
Application scope
ASTM A572/A572M specifies niobium-vanadium microalloyed high-strength low-alloy steel profiles for bridges, buildings, and other structures, covering H-beams, I-beams, channel steels, and angle steels, and classifying them into several grades from 42 to 65 based on strength. The standard utilizes microalloying to provide high yield strength while maintaining good weldability and formability, making it suitable for welded, bolted, or riveted load-bearing components, geared towards weight reduction and high-load-bearing structures.
Typical applications
Widely used in bridge main beams, steel structure frames of factories and high-rise buildings, as well as high-load-bearing components such as lifting equipment, power transmission towers, and construction machinery. Various types of high-strength steel can be combined to form beams, columns, and trusses, reducing cross-section and self-weight under the same load. With its high strength and good weldability, it is suitable for building, bridge, and mechanical structures that require both strength and lightweight construction and are mainly assembled by welding or bolting.
