EN 10025-6 S620Q High Strength Steel Plate

1. What is S620Q High Strength Structural Steel Plate?

S620Q is a high-strength, low-alloy quenched and tempered structural steel plate manufactured in accordance with European Standard EN 10025-6, with material number 1.8914.

Its key features include: high yield strength (≥ 620 MPa), good toughness (impact energy ≥ 30 J at -20°C), excellent overall mechanical properties achieved through quenching and tempering, and weldability under appropriate process control.

S620Q is specifically designed for demanding engineering applications requiring high yield strength, reliable mechanical properties, and efficient structural design. While ensuring stable load-bearing capacity, it significantly reduces structural weight, increases payload capacity, lowers manufacturing and operating costs, and maintains structural safety and reliability. The product is widely used in heavy-duty welded structures, lifting equipment, construction machinery, and load-bearing components.

We supply S620Q high-strength structural steel plates in a variety of specifications. Each batch undergoes rigorous factory inspection to ensure consistent quality and uniform performance. Shipments are accompanied by an EN 10204 3.1 Manufacturer’s Test Certificate (MTC), and we support third-party inspections and full material traceability. We also offer processing services such as custom sizing, precision cutting, and surface treatment.

2. Meaning of the Grade Designation “EN10025-6 S620Q”

Note:

1) Carbon (C): Maintained at a low level to balance strength and weldability while avoiding welding cracks;

2) Alloying elements (Cr, Mo, Ni, V): Enhance strength through solid solution strengthening and precipitation strengthening, while also improving low-temperature toughness;

3) Harmful elements (P, S): Strictly restricted to reduce steel brittleness and susceptibility to hot cracking.

* 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.