S890QL1 (Material Number 1.8925) is a European standard high-strength, fine-grained structural steel. It is a quenched and tempered (+QT) alloyed special steel governed by the EN 10025-6 standard.
Key Characteristics
High Strength: It features a minimum yield strength of 890 MPa (for thicknesses ≤ 50mm).
Extra Toughness: The "L1" suffix indicates exceptional low-temperature toughness, with guaranteed minimum impact energy (typically 30J–40J) at temperatures as low as -60°C (-76°F).
Weldability: Despite its high strength, it is designed for weldability in high-load steel constructions.
Technical Specifications
| Property | Value/Condition |
|---|---|
| Material Number | 1.8925 |
| Standard | EN 10025-6 |
| Min. Yield Strength | 890 N/mm² (up to 50mm thickness) |
| Tensile Strength | 940 – 1100 MPa |
| Min. Impact Temp. | -60°C |
| Delivery Condition | Quenched and Tempered (+QT) |
Typical Applications
S890QL1 is primarily used where weight reduction is critical and extreme operating conditions (cold climates or high stress) are expected:
Lifting Equipment: Mobile crane booms and heavy-duty lifting gear.
Infrastructure: Bridge components and highway construction.
Mining & Earthmoving: Chassis, dumper bodies, and roof supports.
Pressure Vessels: Storage tanks and penstocks.
What welding procedures are required for S890QL1?
Welding S890QL1 requires extremely strict and controlled procedures to preserve its ultra-high strength (890 MPa yield) and guaranteed low-temperature toughness (‑60°C / ≥40 J impact energy). The process is highly specialized and must follow a qualified Welding Procedure Specification (WPS). Here are the essential requirements:
1. Pre‑Weld Essentials
Procedure Qualification: A WPS must be qualified by testing (e.g., EN ISO 15614‑1), including mechanical tests (tensile, impact at ‑60°C, hardness) and macro/micro examination.
Material & Consumable Certification: Verify base metal (EN 10025‑6 S890QL1) and filler metals meet standards. Use low‑hydrogen consumables only.
Joint Preparation: Machined bevels with smooth surfaces. Remove all contaminants (rust, oil, moisture) at least 30 mm from the joint.
2. Filler Metal Selection
Type: Mandatory low‑hydrogen electrodes/wires. Common choices:
SMAW: Basic‑coated electrodes (e.g., E 89 6 B 42 H5 per EN ISO 18275).
GMAW/FCAW: Metal‑cored or flux‑cored wires (e.g., T 89 6 Ni2CrMoTi‑B H5 per EN ISO 16834‑A).
Strength Matching: Often undermatching filler metals (e.g., 770–820 MPa yield) are chosen to improve weld metal toughness and reduce cracking risk, unless design specifically requires matching strength.
3. Critical Welding Parameters
Preheat & Interpass Temperature:
Preheat: Typically 150–200 °C (higher for thick sections or high restraint). Must be applied uniformly.
Interpass Range: Maintain preheat as a minimum, but do not exceed 200–225 °C to avoid excessive HAZ softening.
Heat Input: Must be tightly controlled within a qualified range (often 0.5–1.2 kJ/mm).
Too low → risk of hard, brittle HAZ.
Too high → excessive grain growth and HAZ softening, degrading toughness.
Technique: Use stringer beads or a narrow weave. Avoid long arcs. Ensure full fusion, especially at sidewalls.
4. Post‑Weld Treatments
Post‑Weld Heat Treatment (PWHT): Often mandatory for thicknesses >20 mm or highly restrained joints. Common practice is stress relieving at 550–600 °C to reduce residual stresses, temper the HAZ, and restore toughness.
Slow Cooling: Insulate the weldment after welding to allow gradual cooling to ambient temperature, preventing hydrogen entrapment and cracking.
5. Inspection & Testing
Non‑Destructive Testing (NDT): Ultrasonic testing (UT) or magnetic particle testing (MT) is typically required for all critical welds.
Hardness Survey: To verify HAZ hardness remains within limits (often ≤ 380 HV10).
Charpy Impact Testing: Qualification tests must include impact tests at ‑60 °C on weld metal and HAZ.
1. What is S890QL1 steel?
S890QL1 is an ultra-high-strength quenched and tempered structural steel with a minimum yield strength of 890 MPa, certified for exceptional impact toughness at temperatures as low as -60°C.
2. What does "QL1" mean in S890QL1?
"QL1" indicates the steel is qualified for low-temperature service down to -60°C, with a minimum Charpy impact energy of 40 J at that temperature.
3. Where is S890QL1 commonly used?
It is used in extreme Arctic engineering, offshore platforms in polar regions, critical components of ice-class vessels, and advanced military equipment designed for deep-cold operations.
4. How does S890QL1 differ from S890QL?
S890QL1 guarantees higher impact toughness (≥40 J) at a lower temperature (-60°C), while S890QL is typically tested at -40°C with ≥27 J requirement.
5. What welding procedures are required for S890QL1?
Welding requires strict preheating (150-200°C), low-hydrogen consumables, controlled heat input, and often post-weld heat treatment to prevent cracking and preserve toughness.
6. Is S890QL1 corrosion resistant?
No, S890QL1 is not corrosion-resistant and requires protective coatings (e.g., painting, galvanizing) for use in corrosive or exposed environments.
7. What standards apply to S890QL1 steel?
It is defined by the European standard EN 10025-6, with additional requirements for impact testing at -60°C and certification per EN 10204 Type 3.1.
8. Can S890QL1 be machined easily?
No, machining S890QL1 is extremely difficult due to its high hardness; it requires robust carbide tools, high-pressure coolant, and optimized cutting parameters.
9. What is the price range of S890QL1 steel plate?
S890QL1 is highly expensive, often ranging from €3,000 to €6,000+ per ton, depending 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.
