EN 10025-6 S890Q is a quenched and tempered high strength structural steel plate with a minimum yield strength of 890 MPa. It belongs to the top of the EN 10025-6 strength range, and it is ordered whenever a welded structure must carry very heavy loads while keeping its own weight as low as possible.
In heavy lifting and mining equipment, a higher strength plate is often the cheapest engineering solution, because a thinner section reduces fabrication volume, transport weight and the capacity demanded from the machine itself. S890Q is selected for exactly this reason, and plates of this grade are regularly supplied from Chinese mills to international projects.
What Is EN 10025-6 S890Q Steel Plate?
EN 10025-6 covers flat products of high yield strength structural steels in the quenched and tempered condition. The grade designation is built from three elements:
S – structural steel
890 – minimum yield strength of 890 MPa
Q – quenched and tempered delivery condition with impact testing at -20 °C
The European material number of the grade is 1.8940. The plate is produced by quenching from the austenitising temperature and then tempering, which produces a fine tempered microstructure with a very high yield stress, good toughness and weldability that remains manageable when proper consumables and heat input control are used.
Chemical Composition of EN 10025-6 S890Q
Typical maximum values are listed below. Carbon, phosphorus and sulphur are tightly restricted to protect toughness and weldability at the very high strength level.
| Element | Max (%) |
|---|---|
| C | 0.20 |
| Si | 0.80 |
| Mn | 1.70 |
| P | 0.025 |
| S | 0.015 |
| Al | 0.015 min |
| B | 0.005 |
Micro-alloying with titanium, niobium, vanadium, chromium, nickel and molybdenum is used to obtain the strength and toughness combination required by the standard. The additions stay within the limits set by EN 10025-6 and are reported element by element on the inspection documents, so the delivered heats can be verified against the purchase specification.
Mechanical Properties and Toughness Variants
| Property | Value |
|---|---|
| Tensile strength Rm | 940 – 1100 MPa |
| Yield strength ReH, min | 890 MPa |
| Elongation A, min | 11 % |
| Impact test temperature, grade Q | -20 °C |
The base grade S890Q is impact tested at -20 °C. Two lower temperature variants are produced from the same strength class for cold climate, offshore and arctic service:
S890QL – impact testing at -40 °C
S890QL1 – impact testing at -60 °C
In Chinese standards the closest comparable grade is Q890 of GB/T 16270, which is supplied in the same quenched and tempered condition and covers a similar yield strength level.
Supply Range, Tolerances and Testing
Sizes: thickness 6 mm – 150 mm, width 1000 mm – 3800 mm, length 3000 mm – 18000 mm
Cut-to-size plates and custom widths and lengths can be produced for fabrication requirements
Thickness and flatness tolerances are agreed to EN 10029, with thickness class A as the normal basis; closer flatness limits are set before the order is placed
Ultrasonic testing is carried out to EN 10160, with quality classes up to S2E2 available
Inspection documents are issued to EN 10204 3.1 or 3.2 for full heat traceability
Additional requirements on surface condition or supplementary testing are agreed in advance
Because the specified yield strength is close to the tensile range of ordinary structural steels, plates should be stored, cut and formed without unnecessary heat input, and any local heating that could alter the tempered condition should be avoided unless it is covered by an approved procedure.
Typical Applications of S890Q Steel Plate
The high strength to weight ratio of S890Q makes it the preferred material wherever moving mass, lifting capacity or installed power is limited:
Mobile cranes and tower cranes
Lifting booms, jibs and load-bearing arms
Heavy construction machinery and mining equipment
Transport equipment and special purpose vehicles
Offshore and energy related structures
Highly stressed welded steel structures
In these applications the reduction in plate thickness often lowers the total cost of the finished structure, even though the material itself has a higher price per tonne than conventional structural steel.
Frequently Asked Questions
Q: What is EN 10025-6 S890Q steel plate?
It is a quenched and tempered structural steel plate defined by EN 10025-6 with a minimum yield strength of 890 MPa and a tensile strength range of 940 to 1100 MPa.
Q: What is the material number of S890Q?
The European material number for the grade is 1.8940.
Q: What is the difference between S890Q, S890QL and S890QL1?
All three share the same strength class; they differ in impact test temperature. S890Q is tested at -20 °C, S890QL at -40 °C and S890QL1 at -60 °C.
Q: Which Chinese grade is comparable to S890Q?
The closest equivalent is Q890 of GB/T 16270, which is also supplied in the quenched and tempered condition at a similar yield strength level.
Q: Which thickness range is normally available?
Common supply covers thicknesses from 6 mm to 150 mm, with widths up to 3800 mm and lengths up to 18000 mm, depending on mill capability.
Q: What testing and documentation is supplied with the plates?
Chemical analysis, tensile testing and Charpy impact testing are performed as required by the standard, ultrasonic testing to EN 10160 can be added, and certificates are issued to EN 10204 3.1 or 3.2.
