EN 10025-6 S550QL Steel Plate | S550QL QT High Structural Steel
What is EN 10025-6 S550QL Steel Plate?
SHH STEEL is a professional China Mill-Direct Exporter of high-strength structural steel plates. We are pleased to offer EN 10025-6 S550QL Steel Plate (Material Number 1.8926), a quenched and tempered grade engineered for structural applications that require both high strength and improved low-temperature toughness.
S550QL belongs to the family of EN 10025-6 steel plate products covering high-yield-strength steels in the quenched and tempered condition. Compared with S550Q, the “QL” designation indicates a more stringent impact requirement at –40°C, making this grade suitable for structures exposed to colder service temperatures. After quenching and tempering, the steel develops a fine-grained tempered microstructure that delivers a minimum yield strength of 550 MPa (up to 50 mm thickness) together with reliable Charpy-V toughness at low temperature.
SHH STEEL supplies S550QL plates in thicknesses ranging from 6 mm to 150 mm, widths up to 3000–4000 mm and lengths up to 12000–18000 mm. Custom cutting, ultrasonic testing, surface treatment and third-party inspection services are available. Every plate is delivered with a full EN 10204 3.1 Mill Test Certificate, ensuring complete traceability from the producing mill.
Material Specification
| Parameter | Requirement / Availability |
|---|---|
| Governing Standard | EN 10025-6 |
| Steel Designation | S550QL (1.8926) |
| Delivery Condition | Quenched and Tempered (Q) |
| Product Form | Flat steel plate |
| Thickness Range | 6 mm – 150 mm (thicker plates on request) |
| Width / Length | Up to 3000–4000 mm / 12000–18000 mm |
| Certification | EN 10204 3.1 / 3.2 |
| Additional Testing | UT, Z-test, third-party inspection available |
Chemical Composition
Chemical composition is controlled in accordance with EN 10025-6 for both ladle (heat) analysis and product analysis. The QL grade features tighter limits on phosphorus and sulphur to support improved low-temperature toughness.
Ladle Analysis (Cast Analysis)
| Element | Maximum (%) |
|---|---|
| Carbon (C) | 0.20 |
| Silicon (Si) | 0.80 |
| Manganese (Mn) | 1.70 |
| Phosphorus (P) | 0.020 |
| Sulfur (S) | 0.010 |
| Chromium (Cr) | 1.50 |
| Nickel (Ni) | 2.00 |
| Molybdenum (Mo) | 0.70 |
| Copper (Cu) | 0.50 |
| Niobium (Nb) | 0.06 |
| Vanadium (V) | 0.12 |
| Titanium (Ti) | 0.05 |
| Boron (B) | 0.005 |
| Nitrogen (N) | 0.015 |
Product Analysis
| Element | Maximum (%) |
|---|---|
| Carbon (C) | 0.22 |
| Silicon (Si) | 0.86 |
| Manganese (Mn) | 1.80 |
| Phosphorus (P) | 0.025 |
| Sulfur (S) | 0.012 |
| Chromium (Cr) | 1.60 |
| Nickel (Ni) | 2.10 |
| Molybdenum (Mo) | 0.74 |
| Copper (Cu) | 0.55 |
| Niobium (Nb) | 0.07 |
| Vanadium (V) | 0.14 |
| Titanium (Ti) | 0.06 |
| Boron (B) | 0.006 |
| Nitrogen (N) | 0.016 |
The restricted impurity levels and controlled alloying contribute to reliable toughness performance at –40°C while maintaining acceptable weldability after quenching and tempering.
Mechanical Properties
| Nominal Thickness (mm) | Min. Yield Strength ReH | Tensile Strength Rm | Min. Elongation A | Impact Energy (longitudinal) |
|---|---|---|---|---|
| ≤ 50 | 550 MPa | 640 – 820 MPa | 16 % | 40 J at –40 °C |
| 50 < t ≤ 100 | 530 MPa | 640 – 820 MPa | 16 % | 40 J at –40 °C |
| 100 < t ≤ 150 | 490 MPa | 590 – 770 MPa | 16 % | 40 J at –40 °C |
Density is approximately 7.85 g/cm³. Transverse impact values are also specified in the standard and can be provided when required by the project.
Delivery Conditions
All S550QL plates are supplied in the quenched and tempered condition as required by EN 10025-6. The quenching and tempering heat treatment is carefully controlled to achieve the required combination of high strength and low-temperature toughness.
Additional processing options available from SHH STEEL:
- Shot blasting and shop primer application
- Ultrasonic testing in accordance with EN 10160
- Through-thickness (Z-direction) testing to Z15, Z25 or Z35
- Independent third-party inspection (SGS, BV, TUV, Lloyd’s Register, etc.)
- Precision cutting (flame, plasma or water-jet)
Tolerances
EN 10025-6 S550QL Steel Plate dimensional tolerances are supplied in accordance with EN 10029. For S550QL QT High Structural Steel, customers may select the required class for thickness, width, length and flatness according to project needs. Both mill edges and cut edges (flame or plasma) are available for S550QL steel plate. Tighter tolerances for EN 10025-6 S550QL can be arranged by special agreement when required.
Weldability
S550QL is a high-strength quenched and tempered steel. Successful welding requires careful attention to preheating, heat input and the selection of low-hydrogen consumables in order to preserve toughness in the heat-affected zone, especially for low-temperature service.
Recommended welding consumables:
| Welding Process | Suggested Consumables |
|---|---|
| SMAW (Stick) | E8018-G, E9018-G |
| GMAW / MAG | ER80S-G, ER90S-G |
| FCAW | E81T1-Ni1, E91T1-G |
| SAW | Matching high-strength wire and flux combinations |
Preheating is generally required for thicker plates. Interpass temperature should be strictly controlled, and post-weld heat treatment may be considered for critical applications.
Equivalent Material Grades
| Grade | Standard | Remarks |
|---|---|---|
| S550QL | EN 10025-6 | Primary designation |
| 1.8926 | EN | Material number |
| Q550E / Q550F | GB/T 1591 | Closest Chinese equivalents |
| Selected A514 / A517 grades | ASTM | Similar quenched & tempered concept |
| TStE 550 V | Former DIN | Historical related grade |
Applications
EN 10025-6 S550QL is selected when high strength must be combined with reliable performance at low temperature. Typical applications include:
| Application Area | Typical Components / Keywords |
|---|---|
| Heavy Construction | Crane booms, heavy frames, high-load columns – S550QL Structural Steel |
| Bridge Engineering | Main girders, support structures – S550QL Bridge |
| Mining & Earthmoving Equipment | Chassis, boom structures – S550QL Mining |
| Offshore & Marine | Platform components, lifting equipment – S550QL Offshore |
| Low-Temperature Structures | Structures requiring –40°C toughness – S550QL Low Temperature |
| Energy & Power | Wind turbine components, heavy fabrications – S550QL Energy |
| General Heavy Fabrication | High-strength welded assemblies – S550QL Fabrication |
Why Choose SHH STEEL
SHH STEEL is a China Mill-Direct Exporter. We maintain long-term strategic cooperation with major Chinese steel mills and act as a first-level agent. This direct supply model allows us to offer competitive mill-direct pricing, shorter lead times, consistent quality and full Mill Test Certificates (EN 10204 3.1 / 3.2) for EN 10025-6 S550QL Steel Plate.
Our experienced export and technical teams provide support on material selection, welding procedures, cutting and processing. Customers benefit from reliable supply and professional service for high-strength quenched and tempered steel projects requiring improved low-temperature performance.
FAQ
- What does “QL” mean in S550QL?“Q” indicates the quenched and tempered condition, while “L” means the steel meets higher impact energy requirements at –40°C.
- What is the difference between S550Q and S550QL?Both grades have the same strength level. S550Q is impact tested at –20°C, whereas S550QL is tested at –40°C and provides higher toughness values for colder service conditions.
- What is the material number of S550QL?1.8926
- Can SHH STEEL supply S550QL with Z-direction testing?Yes. Z15, Z25 and Z35 testing can be arranged according to project requirements.
Conclusion
EN 10025-6 S550QL (1.8926) quenched and tempered steel plate from SHH STEEL combines high yield strength of 550 MPa with excellent toughness at –40°C. As a China Mill-Direct Exporter, we provide competitive pricing, reliable quality and full technical support. Contact SHH STEEL today for stock availability, pricing or processing services.
EN 10025-6 S550QL Steel Plate, S550QL steel plate, S550QL QT, EN 10025 S550QL, S550QL equivalent, S550QL supplier, 1.8926
Quality Steel Needed? Inquire for Offers
Related Products
