EN 10025-6 S690QL1 Steel Plate | S690QL1 QT High Structural Steel
What is EN 10025-6 S690QL1 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 S690QL1 Steel Plate (Material Number 1.8988), a quenched and tempered grade engineered for the most demanding structural applications that require both very high strength and exceptional low-temperature toughness.
S690QL1 belongs to the family of EN 10025-6 steel plate products covering high-yield-strength steels in the quenched and tempered condition. The “QL1” designation indicates the most stringent impact requirement within the S690 series, with testing performed at –60°C. This makes the grade particularly suitable for structures exposed to arctic or extremely cold service conditions. After quenching and tempering, the steel develops a fine-grained tempered microstructure that delivers a minimum yield strength of 690 MPa (up to 50 mm thickness) together with high Charpy-V toughness at very low temperature.
SHH STEEL supplies S690QL1 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 | S690QL1 (1.8988) |
| 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 QL1 grade features tighter limits on phosphorus and sulphur to support superior 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 the excellent toughness performance at –60°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 | 690 MPa | 770 – 940 MPa | 14 % | 30 J at –60 °C |
| 50 < t ≤ 100 | 650 MPa | 770 – 940 MPa | 14 % | 30 J at –60 °C |
| 100 < t ≤ 150 | 630 MPa | 710 – 900 MPa | 14 % | 30 J at –60 °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 S690QL1 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 exceptional 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 S690QL1 Steel Plate dimensional tolerances are supplied in accordance with EN 10029. For S690QL1 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 S690QL1 steel plate. Tighter tolerances for EN 10025-6 S690QL1 can be arranged by special agreement when required.
Weldability
S690QL1 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 extreme low-temperature service.
Recommended welding consumables:
| Welding Process | Suggested Consumables |
|---|---|
| SMAW (Stick) | E10018-G, E11018-G |
| GMAW / MAG | ER100S-G, ER110S-G |
| FCAW | E101T1-G, E111T1-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 is often recommended for critical applications operating at very low temperatures.
Equivalent Material Grades
| Grade | Standard | Remarks |
|---|---|---|
| S690QL1 | EN 10025-6 | Primary designation |
| 1.8988 | EN | Material number |
| Q690F | GB/T 1591 | Closest Chinese equivalent |
| A514 Grade F / Q | ASTM | Similar quenched & tempered concept |
| TStE 690 V | Former DIN | Historical related grade |
Applications
EN 10025-6 S690QL1 is selected when very high strength must be combined with outstanding performance at extremely low temperatures. Typical applications include:
| Application Area | Typical Components / Keywords |
|---|---|
| Heavy Construction | Crane booms, heavy frames, high-load columns – S690QL1 Structural Steel |
| Mobile Cranes & Lifting | Boom structures, telescopic arms – S690QL1 Crane |
| Mining & Earthmoving Equipment | Chassis, boom structures – S690QL1 Mining |
| Offshore & Arctic Structures | Platform components, lifting equipment – S690QL1 Offshore |
| Extreme Low-Temperature Service | Structures requiring –60°C toughness – S690QL1 Low Temperature |
| Energy & Power | Wind turbine components, heavy fabrications – S690QL1 Energy |
| General Heavy Fabrication | Critical high-strength welded assemblies – S690QL1 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 S690QL1 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 superior low-temperature performance.
FAQ
- What does “QL1” mean in S690QL1?“Q” indicates the quenched and tempered condition, while “L1” means the steel meets the highest impact energy requirements at –60°C within the S690 series.
- What is the difference between S690QL and S690QL1?Both grades have the same strength level. S690QL is impact tested at –40°C, whereas S690QL1 is tested at –60°C and is intended for more severe low-temperature service.
- What is the material number of S690QL1?1.8988
Conclusion
EN 10025-6 S690QL1 (1.8988) quenched and tempered steel plate from SHH STEEL combines high yield strength of 690 MPa with outstanding toughness at –60°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.
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