EN 10025-6 S620Q High Strength Steel Plate

EN 10025-6 S620Q is a high yield strength quenched and tempered structural steel under the European standard (EN), widely used in heavy-duty structural applications that require high material strength, toughness, and machinability.

Standard and Grade Designation

1. Standard: EN 10025-6

The full title is "Hot-rolled structural steels - Part 6: Technical delivery conditions for flat products of high yield strength structural steels in the quenched and tempered condition," which is a unified European standard for high-strength structural steel.



2. Grade: S620Q

S: Structural steel.

620: The specified minimum yield strength is 620MPa.

Q: The delivery condition is Quenched and Tempered.

The chemical composition of S690QL ensures hardenability, strength, and toughness. EN 10025-6 specifies the limits for key elements, with the following typical ranges:

Carbon Equivalent of S620Q High Strength Steel Plate

* The carbon equivalent value varies depending on the thickness.For detailed information, please contact us for inquiries.

* Carbon equivalent (CEV) is calculated using the International Institute of Welding (IIW) formula:

CEV = C + Mn/6 + (Cr+Mo+V)/5 + (Ni+Cu)/15

* The mechanical properties of S620Q high strength structural steel plate vary with thickness.

S620Q is primarily used in heavy-duty structures under high load, lightweight, or low-temperature conditions due to its combined advantages of "high strength + good toughness + weldability." Typical application fields include:

Construction Machinery: Crane booms, excavator arms, bulldozer frames;

Heavy Steel Structures: Load-bearing components of long-span bridges, steel columns/beams for high-rise buildings, crane beams in industrial plants;

Special Vehicles: Mining dump truck bodies, container chassis;

Energy & Offshore: Wind turbine tower flanges, offshore platform support structures;

Pressure Vessels: High-pressure storage tanks (must additionally meet supplementary requirements of pressure vessel standards).

Delivery Conditions

S620Q is typically delivered in the quenched and tempered condition, with surface treatments such as sandblasting and painting available as required.

Weldability

S690Q is weldable, but Although it can be welded, due to its high strength, preheating is required before welding (preheating temperature should be adjusted according to thickness, usually ≥100°C). Stress relief treatment is necessary after welding to avoid cold cracks. The use of low-hydrogen electrodes is recommended.

The Differences Between Grades Within The Same Series

Summary

EN 10025-6 S620Q is a premium, high-performance quenched and tempered structural steel plate offering an exceptional combination of strength, toughness, and weldability for the most demanding engineering applications.