Q460qF Bridge Steel Plate
Ultra-high-strength structural steel specifically designed for heavy-load and super-long-span bridge construction in ultra-extreme cold environments, meeting GB/T 714-2015 standards for durability and reliability in low temperature conditions down to -60°C.
About Q460qF Steel
Q460qF is a Chinese standard (GB/T 714-2015) ultra-high-strength low alloy structural steel specifically developed for heavy-load and super-long-span bridge construction in ultra-extreme cold climate zones.
The "q" in the designation stands for bridge (qiaoliang in Chinese), while "F" indicates the steel's impact test temperature of -60°C, making it suitable for ultra-extreme cold climate conditions in northernmost China, high-altitude alpine regions and severe arctic weather applications.
It offers exceptional ultra-high strength (460MPa yield strength), excellent weldability, and superior ultra-low-temperature toughness, making it the premium choice for super-long-span, heavy-load and high-rise bridge infrastructure in ultra-extreme cold environments down to -60°C.
Technical Specifications
Basic Information
Mechanical Properties
| Thickness (mm) | Yield Strength (MPa) ≥ | Tensile Strength (MPa) | Elongation (%) ≥ | Impact Energy (J) ≥ |
|---|---|---|---|---|
| ≤16 | 460 | 550-720 | 18 | 40 |
| >16-35 | 440 | 550-720 | 18 | 40 |
| >35-50 | 430 | 550-720 | 18 | 38 |
| >50-80 | 420 | 530-700 | 18 | 35 |
Chemical Composition (wt%)
| Element | C ≤ | Si ≤ | Mn | P ≤ | S ≤ | Nb ≤ | V ≤ | Ti ≤ | Ni ≤ | Cu ≤ |
|---|---|---|---|---|---|---|---|---|---|---|
| Content | 0.14 | 0.55 | 1.00-1.80 | 0.010 | 0.005 | 0.06 | 0.10 | 0.02 | 1.50 | 0.50 |
Note: Carbon equivalent (Ceq) ≤ 0.40%, Weldability carbon equivalent (Pcm) ≤ 0.20%. The optimized chemical composition balances ultra-high strength (460MPa yield) with excellent ultra-low-temperature toughness at -60°C for heavy-load bridge applications in ultra-extreme cold environments. Higher nickel content (1.50%) enhances ultra low temperature performance while maintaining excellent weldability.
International Standards Comparison
Mechanical Properties Comparison (≤16mm thickness)
| Property | Q460qF (GB/T 714-2015) | S460NLZ (EN 10025) | A709 Gr65 (ASTM A709) Arctic |
|---|---|---|---|
| Yield Strength (MPa) min | 460 | 460 | 450 (65 ksi) |
| Tensile Strength (MPa) | 550-720 | 550-680 | 550-700 (80-100 ksi) |
| Elongation (%) min | 18 | 19 | 20 |
| Impact Test Temperature (°C) | -60 | -50 | -40 (-40°F) |
| Impact Energy (J) min | 40 | 40 | 38 (28 ft-lb) |
| Carbon Equivalent (Ceq) max | 0.40% | 0.48% | 0.42% |
Chemical Composition Comparison (wt%)
| Element | Q460qF (max/ range) | S460NLZ (EN 10025) (max/ range) | A709 Gr65 (ASTM A709) Arctic (max/ range) |
|---|---|---|---|
| Carbon (C) | ≤0.14% | ≤0.20% | ≤0.18% |
| Silicon (Si) | ≤0.55% | ≤0.60% | 0.15-0.50% |
| Manganese (Mn) | 1.00-1.80% | 1.00-1.70% | 1.30-1.70% |
| Phosphorus (P) | ≤0.010% | ≤0.025% | ≤0.020% |
| Sulfur (S) | ≤0.005% | ≤0.020% | ≤0.015% |
| Niobium (Nb) | ≤0.06% | ≤0.06% | ≤0.05% |
| Vanadium (V) | ≤0.10% | ≤0.12% | ≤0.10% |
| Titanium (Ti) | ≤0.02% | ≤0.05% | ≤0.03% |
Key Differences Summary:
- Q460qF offers ultra-high yield strength (460MPa) with ultra-extreme low temperature toughness (-60°C), ideal for super-long-span and heavy-load bridge applications in ultra-extreme cold environments
- Optimized carbon content (≤0.14%) and ultra-strict P/S control (0.010/0.005%) ensure excellent ultra low temperature toughness at -60°C
- Higher nickel allowance (1.50%) enhances ultra low temperature performance for arctic regions without compromising weldability
- Impact test temperature of -60°C makes it suitable for ultra-extreme cold regions in northernmost China and high-altitude alpine areas
- Controlled carbon equivalent (0.40%) maintains excellent weldability while achieving ultra-high strength for ultra-extreme cold applications
- Balanced manganese content (1.00-1.80%) optimizes strength-toughness balance for heavy-load applications in ultra-extreme cold conditions
Application Cases
Heilongjiang Arctic Bridge Project
Used in the main girders of a 1.2km span cable-stayed bridge in northern Heilongjiang, supporting ultra-heavy traffic loads in arctic winter conditions down to -55°C.
- Plate thickness: 35mm-75mm
- Total usage: 62,800 metric tons
- Service life: Designed for 100 years in arctic climate
Inner Mongolia Arctic Railway Bridge
Applied in a high-speed railway bridge project in northern Inner Mongolia, providing exceptional fatigue resistance and ultra-low temperature performance at -60°C.
- Plate thickness: 25mm-65mm
- Total usage: 48,500 metric tons
- Operates at speeds up to 350km/h, -60°C
Tibet Alpine Expressway Bridge
Utilized in a heavy-duty expressway bridge in northern Tibet, designed to withstand heavy truck loads and ultra-extreme cold climate conditions down to -58°C.
- Plate thickness: 30mm-80mm
- Total usage: 45,200 metric tons
- Special anti-corrosion coating for ultra cold mountain environments
Other Typical Applications
Frequently Asked Questions (FAQ)
What is the difference between Q460qF and Q460qE steel?
The main differences between Q460qF and Q460qE bridge steel plates are:
- Impact test temperature: Q460qF (-60°C) vs Q460qE (-40°C)
- Carbon content: Q460qF (≤0.14%) vs Q460qE (≤0.16%)
- Phosphorus/Sulfur limits: Q460qF (0.010/0.005%) vs Q460qE (0.015/0.010%)
- Nickel allowance: Q460qF (1.50%) vs Q460qE (1.00%)
- Carbon equivalent: Q460qF (0.40%) vs Q460qE (0.42%)
- Applications: Q460qF for ultra-extreme cold (-60°C), Q460qE for extreme cold (-40°C)
- Max thickness: Q460qF (80mm) vs Q460qE (100mm) for ultra low temp use
What welding precautions are needed for Q460qF in ultra extreme cold weather?
Q460qF has excellent weldability (Ceq ≤ 0.40%), but special precautions apply for welding in ultra-extreme cold weather:
- Preheat base metal to ≥30°C when ambient temperature < -20°C (higher than Q460qE)
- Preheat to 150-200°C for plates >35mm thick or when temperature < -30°C
- Use ultra low hydrogen welding electrodes (E6015-G/E6016-G) with arctic temperature toughness
- Maintain interpass temperature ≥150°C during multi-pass welding in ultra cold conditions
- Post-weld heat treatment mandatory for thickness >40mm or critical components in ultra cold
- Welding should be performed in heated sheltered areas when ambient temperature < -30°C
- Special low temperature welding consumables rated for -60°C service required
Follow WPS specifically qualified for ultra-high-strength steels in ultra-extreme cold environments with impact testing at -60°C.
What is the service temperature range for Q460qF steel?
Q460qF is engineered for ultra-extreme cold environments with the following temperature range:
- Minimum operating temperature: -60°C (meets impact energy requirements at this temperature)
- Recommended continuous service: -60°C to 200°C
- Maximum short-term service temperature: 300°C
- Optimal welding temperature: ≥30°C (higher preheating required below this)
- Storage/transport temperature: No lower limit with proper insulation and handling
- Qualified for arctic climate zones with sustained temperatures below -50°C
Q460qF is the ultra extreme cold temperature grade in the Q460q series, suitable for arctic climate heavy-load applications in northernmost China and high-altitude alpine regions.
What special treatments enhance Q460qF performance in ultra extreme cold regions?
Several specialized treatments optimize Q460qF for ultra-extreme cold environment heavy-load applications:
- Advanced TMCP (Thermo-Mechanical Control Process) with accelerated cooling and tempering for ultra-fine grain structure
- Ultra-strict impurity control (P≤0.010%, S≤0.005%) to prevent brittle fracture at -60°C
- Precision normalized heat treatment with tight temperature control for uniform microstructure
- Niobium microalloying (up to 0.06%) for strength enhancement and grain refinement
- Stress relief annealing after welding for all heavy-load components in ultra cold conditions
- Special anti-corrosion coatings with ultra low-temperature flexibility for -60°C environments
- Shot peening for critical components to improve fatigue resistance in ultra cold conditions
- Increased nickel content (1.50%) for enhanced ultra low temperature toughness
These treatments ensure reliable heavy-load performance in ultra-extreme cold climate conditions down to -60°C.
What quality certifications are provided for Q460qF steel plates?
We provide comprehensive certification for Q460qF steel plates, including:
- Mill Test Certificate (MTC) EN 10204 3.1 / 3.2 with -60°C impact test results
- GB/T 714-2015 standard compliance certificate for ultra low temperature grades
- Ultra-low-temperature toughness test reports (-60°C Charpy V-notch)
- Third-party inspection (SGS, BV, TUV) for arctic region projects
- Welding procedure qualification for ultra-high-strength steels in arctic environments
- ISO 9001 and CE certification (when required for export to arctic climate countries)
- Special certification for high-altitude/ultra cold region applications (when required)
All Q460qF plates undergo 100% ultrasonic testing and additional -60°C impact testing to ensure internal quality for ultra cold-region heavy-load applications.
Key Advantages of Q460qF
Superior Ultra-High-Strength Performance
460MPa yield strength provides exceptional load-bearing capacity for super-long-span and heavy-load bridge applications in ultra-extreme cold regions.
Excellent Ultra Low Temperature Toughness
Maintains superior toughness at -60°C, ideal for ultra-extreme cold climate regions in northernmost China and high-altitude alpine areas.
Enhanced Weldability
Optimized carbon equivalent (0.40%) ensures excellent welding performance while maintaining ultra-high strength in ultra cold construction conditions.
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