EN 10025-6 — Quenched and tempered high-strength structural steel
Grades
S460Q, S460QL, S460QL1, S500Q, S500QL, S550Q, S550QL, S620Q, S620QL, S690Q, S690QL, S690QL1, S890Q, S890QL, S960Q, S960QL
Chemical composition and mechanical properties
| Grade | Chemical composition | Mechanical properties |
|---|---|---|
| S460Q | C≤0.18, Mn≤1.70, P≤0.020, S≤0.010, Si≤0.50, N≤0.015, B≤0.005, Cr≤1.50, Cu≤0.50, Mo≤0.50, Nb≤0.05, Ni≤2.00, Ti≤0.05, V≤0.10 | Rm 570-720 MPa, Rp0.2 ≥460 MPa, A≥17%, 0℃ Akv≥30J |
| S460QL | Same as S460Q, P≤0.020, S≤0.010 | Rm 570-720 MPa, Rp0.2 ≥460 MPa, A≥17%, -40℃ Akv≥30J |
| S460QL1 | Same as S460Q, P≤0.020, S≤0.010 | Rm 570-720 MPa, Rp0.2 ≥460 MPa, A≥17%, -60℃ Akv≥30J |
Application scope
EN 10025-6 specifies high-strength structural steel plates delivered in a quenched and tempered condition, with grades including Q, QL, and QL1 series, and strengths ranging from 460 to 960. The quenching and tempering process imparts a high yield strength and good toughness. The standard specifies the composition, tensile strength, and impact requirements at different temperatures, making it suitable for welded load-bearing components and applications requiring heavy loads, lightweight construction, and high safety.
Typical applications
Primarily used in heavy-duty construction machinery, crane booms and jibs, high-stress components in mining and engineering equipment, as well as pressure vessels and offshore platform structures; also used in structural components bearing large concentrated loads. With its high yield strength, it allows for significant reduction in cross-section and weight, making the QL series suitable for cryogenic conditions. Ideal for heavy equipment and structures with stringent requirements for high strength, reliability, and low-temperature toughness.
