S890QL1 is an ultra-high-strength quenched and tempered fine-grain structural steel supplied to EN 10025-6. It offers a minimum yield strength of 890 MPa for plates up to 50 mm thick, combined with guaranteed impact toughness at very low service temperatures. Several standards govern the grade, its testing, its certification, and the design of structures that use it. This article explains which standards apply and how they are used.
Product Standard EN 10025-6
The product standard EN 10025-6 covers hot-rolled flat and long products of high-yield-strength structural steels in the quenched and tempered condition. Within this standard, the designation S890QL1 indicates a structural steel with a minimum yield strength of 890 MPa, delivered quenched and tempered, with improved low-temperature impact toughness specified at minus 60 degrees C. The material number of the grade is 1.8925 under the European steel numbering system.
Chemical Composition and Carbon Equivalent
EN 10025-6 sets maximum limits for the alloying elements: carbon 0.20 percent, silicon 0.80 percent, manganese 1.70 percent, phosphorus 0.020 percent, sulfur 0.010 percent, and controlled additions such as chromium 1.50 percent, molybdenum 0.70 percent, nickel 2.0 percent, boron 0.005 percent, and vanadium 0.12 percent maximum. The standard also limits the carbon equivalent value, typically not exceeding 0.82 for the grade, which supports welding by limiting hardenability. The chemistry is designed to achieve high strength after quenching and tempering while retaining acceptable toughness and weldability.
Mechanical Properties and Impact Testing
For plates of 3 to 50 mm thickness, the minimum yield strength is 890 MPa and the tensile strength range is 940 to 1100 MPa. Impact testing is performed in accordance with EN ISO 148-1, and the QL1 quality requires a minimum average impact energy of 30 J at minus 60 degrees C. Tensile properties are verified according to EN ISO 6892-1. The combination of high yield strength and guaranteed sub-zero impact energy makes the grade suitable for dynamically loaded structures in cold environments.
Certification and Testing Standards
Mill test certificates are issued in accordance with EN 10204. Plates for structural use are normally supplied with a Type 3.1 certificate, which declares that the material conforms to the order and is verified by inspection documents produced by the manufacturer's authorized representative. Additional testing can be agreed between the purchaser and the manufacturer, and supplementary requirements of EN 10025-6 may apply where specified.
Design and Fabrication Standards
Structures designed with S890QL1 are commonly calculated in accordance with EN 1993-1-12, which extends the application of Eurocode 3 to steel grades up to S960. Welding procedures are qualified under EN ISO 15614-1 and executed with low-hydrogen consumables, preheat, and interpass temperature control as required by EN 1011-2. These standards together provide a complete framework for specifying, testing, certifying, designing, and welding the material.
Frequently Asked Questions
Which standard covers S890QL1 steel?
S890QL1 is a product designation from EN 10025-6, the European standard for quenched and tempered high-yield-strength structural steels.
What is the difference between S890QL and S890QL1?
Both grades share the same strength requirements. S890QL specifies impact testing at minus 40 degrees C, while S890QL1 specifies impact testing at the lower temperature of minus 60 degrees C.
What is the material number of S890QL1?
The material number assigned to S890QL1 is 1.8925 under the European steel numbering system.
What certificate is normally supplied with S890QL1 plate?
Plates are normally supplied with an EN 10204 Type 3.1 mill test certificate issued by the manufacturer.
What is the minimum yield strength of S890QL1?
The minimum yield strength is 890 MPa for plate thicknesses up to 50 mm.
Can S890QL1 be welded?
Yes, welding is possible with qualified procedures, low-hydrogen consumables, preheat, and controlled heat input to avoid cold cracking and loss of strength in the heat-affected zone.