What EN 10025-6 S890Q Plate Is
S890Q is a high-strength structural steel plate defined by EN 10025-6, the part of the European structural steel standard that covers flat products of high yield strength steel in the quenched and tempered condition. The designation reads directly from the standard: S for structural steel, 890 for the minimum yield strength in megapascals at the lower thickness range, and Q for quenched and tempered delivery. The European material number of S890Q is 1.8940.
Because it is supplied in the quenched and tempered state, S890Q delivers a strength level close to three times that of ordinary S275 construction steel. The practical consequence is weight: a structure designed in S890Q can carry the same load with far less steel, which is decisive for mobile equipment, long-span bridges and any application where dead weight directly reduces payload or increases foundation cost.
Chemical Composition
EN 10025-6 controls the ladle analysis of S890Q within the limits below. All values are maximum percentages by mass.
| Element | C | Si | Mn | P | S | N | B |
|---|---|---|---|---|---|---|---|
| Max % | 0.20 | 0.80 | 1.70 | 0.020 | 0.010 | 0.015 | 0.005 |
| Element | Cr | Cu | Mo | Nb | Ni | Ti | V |
| Max % | 1.50 | 0.50 | 0.70 | 0.06 | 2.00 | 0.05 | 0.12 |
Zirconium may also be present up to 0.15 %. The composition is deliberately lean in carbon and rich in micro-alloying and hardening elements: boron raises hardenability so that the plate through-hardens during quenching, nickel improves toughness at low temperature, and niobium, vanadium and titanium form fine carbonitrides that stabilise the tempered structure. Phosphorus and sulphur are held very low because cleanliness is a precondition for adequate toughness in a steel of this strength class.
Mechanical Properties
As with all grades in EN 10025-6, the guaranteed values depend on nominal thickness.
| Thickness range (mm) | ReH min (MPa) | Tensile strength Rm (MPa) | Elongation A min (%) | Charpy V-notch at −20 °C |
|---|---|---|---|---|
| 3 < t ≤ 50 | 890 | 940–1100 | 11 | 30 J min |
| 50 < t ≤ 100 | 830 | 880–1100 | 11 | 30 J min |
| 100 < t ≤ 150 | 800 | 820–1000 | 11 | 30 J min |
The stepped yield values reflect the fact that heavy quenched and tempered plate cannot be through-hardened as uniformly as thin plate. Engineers should therefore take the governing design value from the row that matches the actual section, not from the headline 890 MPa figure. Where service temperature is lower than −20 °C, the low-temperature variants S890QL and S890QL1 are specified instead of plain S890Q.
Supply Range and Delivery Conditions
Typical supply: thickness 3 mm to 300 mm, width 1500 mm to 4050 mm, length 3000 mm to 27000 mm, subject to mill capability.
Delivery condition: quenched and tempered as required by EN 10025-6; the plate must not be re-austenitised or flame-straightened by the fabricator without a qualified procedure.
Optional supplementary requirements: ultrasonic examination to EN 10160, Charpy V-notch impact testing, through-thickness (Z-direction) testing at Z15, Z25 or Z35, and third-party inspection by recognised classification societies or independent inspection bodies.
Inspection documents: certificate type 3.1 to EN 10204 as standard, with 3.2 certification available when the order requires it.
Surface protection: shot blasting and priming, or coating, can be applied before shipment.
Applications of S890Q Plate
The grade is chosen where strength to weight ratio governs the design.
Mobile cranes, aerial platforms and lifting equipment, where every kilogram of structure reduces usable capacity.
Bridges and heavy civil structures, including long-span girders and bearing components.
Mining and earthmoving machinery, such as excavator booms, buckets and dump truck bodies.
Wind power and offshore structures, including tower components and transition pieces.
Heavy-duty vehicle frames and chassis for transport equipment.
Industrial presses, forming tools and machine components subject to high static load.
S890Q is a structural steel and is not intended for pressure vessel or boiler service; those applications follow dedicated pressure equipment standards. Where designers need to reduce weight in an existing S690Q structure, S890Q is a natural step up, provided that stiffness, fatigue and weldability are all re-checked rather than assumed from the yield strength alone.
Fabrication Notes
Cutting: plasma or laser cutting is preferred; flame cut faces in very high strength plate should be lightly ground to remove the hardened layer before welding.
Welding: S890Q is weldable but requires a qualified procedure with controlled heat input, matched low-hydrogen consumables and, for thicker sections, preheating and interpass control.
Forming: cold forming is limited by the high yield strength; generous bend radii apply, and hot forming is not permitted without mill approval because it alters the tempered structure.
Machining: the tempered microstructure machines with carbide tooling at moderate cutting speeds, and drilling of thick sections benefits from rigid fixturing.
Handling and storage: store dry and flat, and avoid impact damage to plate edges.
Frequently Asked Questions
Q: What is S890Q steel plate?
S890Q is a quenched and tempered high-strength structural steel plate defined by EN 10025-6 with a minimum yield strength of 890 MPa at thickness up to 50 mm.
Q: What is the material number of S890Q?
The European material number of S890Q is 1.8940.
Q: What thickness range is available?
Common supply covers thickness from 3 mm to 300 mm with widths up to about 4050 mm, depending on mill capability and the mechanical property requirements of the ordered thickness.
Q: What are the mechanical properties of S890Q?
Minimum yield strength 890 MPa up to 50 mm, tensile strength 940–1100 MPa, minimum elongation 11 % and impact energy of at least 30 J at −20 °C.
Q: What is the difference between S890Q and S890QL?
S890QL and S890QL1 are the low-temperature variants, tested at −40 °C and −60 °C respectively, and are preferred for cold-climate or offshore service.
Q: Can S890Q be used for pressure vessels?
No. S890Q is a structural steel. Pressure equipment must comply with dedicated pressure vessel standards, which specify different chemistry, testing and design rules.
Q: Can S890Q be welded?
Yes, with a qualified welding procedure that controls heat input, interpass temperature and hydrogen, and uses consumables matched to an 890 MPa base metal.
