S890Q is a European grade of high-yield-strength structural steel defined under the EN 10025-6 standard. It is a quenched (Q) and tempered (T) steel designed for high-load applications where weight reduction and high strength are critical.
1. Key Specifications
Material Number: 1.8940.
Yield Strength: Minimum 890 MPa (for nominal thicknesses up to 50mm).
Tensile Strength: Typically ranges between 940–1100 MPa.
Impact Testing: S890Q specifically requires a minimum impact energy value at temperatures not lower than -20°C. (Note: Variants like S890QL and S890QL1 are tested at -40°C and -60°C, respectively).
2. Common Applications
Due to its high strength-to-weight ratio, S890Q is used in safety-critical and heavy-duty industrial sectors:
Lifting & Earthmoving: Booms for mobile cranes, dumper bodies, and chassis for heavy road vehicles.
Structural Engineering: Bridge components, offshore structures, and supporting frameworks.
Energy & Pressure Vessels: Penstocks, spiral cases for power plants, and fixed or transportable storage tanks.
3. Manufacturing & Fabrication
Delivery Condition: Water quenched and tempered (+QT) to achieve a fine-grained microstructure of bainite and tempered martensite.
Workability: Despite its high strength, it is weldable and suitable for bolted or riveted structures.
Thermal Cutting: Research indicates that while traditional flame cutting is common, laser and plasma cutting methods can improve the fatigue life of the cut edges.
Can S890Q be machined easily?
No, S890Q cannot be machined easily. It is classified as a very difficult-to-machine material due to its extreme hardness (typically 280–360 HBW) and very high strength (890 MPa yield). Machining requires specialized tooling, rigid setups, and controlled parameters to avoid excessive tool wear, poor surface finish, or even workpiece damage.
Key Challenges in Machining S890Q:
Rapid Tool Wear: The high hardness and abrasiveness (especially from surface scale) cause accelerated wear on cutting edges.
High Cutting Forces: Demands extremely rigid machine tools, fixtures, and tool holders to prevent vibration and chatter.
Heat Generation: Intense friction generates significant heat, which can soften tooling or alter the material's heat-treated properties if not controlled.
Work Hardening: Improper machining (e.g., using low feed rates or worn tools) can harden the surface further, making subsequent passes even more difficult.
Brittleness Risk: The material's lower ductility increases sensitivity to notch effects or cracking if machining induces stress concentrations.
Essential Machining Guidelines:
Tooling:
Material: Use premium-grade carbide (e.g., C3/C4 micro-grain), cermet, or coated carbide inserts. For heavy roughing, ceramic inserts may be used in stable conditions.
Geometry: Sharp cutting edges with positive rake angles to reduce cutting forces. Robust tool holders are critical.
Cutting Parameters:
Cutting Speed (Vc): Low to moderate – typically 60–120 m/min for turning with carbide.
Feed Rate: Use adequate feed to avoid rubbing and work hardening.
Depth of Cut: Sufficient to cut beneath any hardened surface layer.
Coolant & Lubrication:
High-pressure, high-quality coolant is essential to dissipate heat, extend tool life, and flush chips.
Machine & Setup:
Maximum rigidity in the machine, workpiece clamping, and tool holding is non‑negotiable.
Preparatory Step:
Remove the hard, decarburized surface scale (often present on as‑delivered plates) via grinding or rough machining before finish machining.
Summary:
While S890Q is machinable, it requires:
Heavy-duty, rigid CNC machinery
Premium-grade cutting tools
Optimized, conservative cutting parameters
Effective high-pressure coolant systems
Experienced operators
For critical components, conducting test runs and collaborating with tooling specialists is highly recommended to develop a stable and economical machining process. Machining S890Q is a specialized task justified only by the performance benefits of this ultra‑high‑strength steel.
Technical data
About S890Q detail information, please refer to our mill technical date in following:
EN10025-6 S890Q quenched and tempered steel plate Chemical composition
| Grade | C % | Si % | Mn % | P % | S % | N % | B % | Cr % |
| S890Q | 0.200 | 0.800 | 1.700 | 0.025 | 0.015 | 0.015 | 0.005 | 1.500 |
| Cu % | Mo % | Nb % | Ni % | Ti % | V % | Zr % | ||
| 0.500 | 0.700 | 0.060 | 2.000 | 0.050 | 0.120 | 0.150 |
EN10025-6 S890Q quenched and tempered steel plate mechanical properties
| Grade | Thickness(mm) | Min Yield (Mpa) | Tensile(MPa) | Elongation (%) | Min Impact Energy | |
| S890Q | 8mm-50mm | Min 890Mpa | 940-1100Mpa | 11% | -20 | Min 30J |
| 51mm-100mm | Min 830Mpa | 880-1100Mpa | 11% | -20 | Min 30J | |
| 101mm-150mm | Min 800Mpa | 820-1000Mpa | 11% | -20 | Min 30J |
Gnee steel are special field of exporting EN10025-6 S890Q quenched and tempered steel plate on base of large relation with our HBIS Wuyang mill in China. If you have any inquiry in steel plates, Please feel free to contact us.
What is S890Q steel?
S890Q is a very high-strength quenched and tempered structural steel with a minimum yield strength of 890 MPa, designed for extreme load-bearing applications.
What are the properties of S890Q steel?
It offers exceptional strength, good toughness at low temperatures, and weldability with proper procedures, though it is more brittle than lower-grade steels.
Where is S890Q steel used?
S890Q is used in heavy-duty crane booms, advanced mining equipment, high-performance military vehicles, and specialized structural components where maximum strength-to-weight ratio is critical.
How does S890Q compare to S690Q?
S890Q has a higher yield strength (890 MPa vs. 690 MPa) but lower toughness and weldability, making it suitable for more demanding, lightweight designs.
What welding procedures are required for S890Q?
Welding S890Q requires strict preheating (often 150-200°C), low-hydrogen electrodes, controlled heat input, and post-weld stress relief to avoid cracking.
Is S890Q steel corrosion resistant?
No, S890Q is not corrosion-resistant and requires protective coatings like painting or galvanizing for use in exposed environments.
What standards cover S890Q steel?
It is primarily specified under the European standard EN 10025-6 for quenched and tempered high-strength structural steels.
Can S890Q be machined easily?
Machining S890Q is difficult due to its extreme hardness and strength; it requires robust tooling, slow speeds, and ample cooling.
What is the price of S890Q steel plate?
S890Q is significantly more expensive than lower-strength grades, with prices varying based on thickness, quantity, and certification requirements.
Full specification and details are available on request. The above information is provided for guidance purposes only. For specific design requirements please contact our technical sales staff.
