Q345qC Bridge Steel Plate
High-strength structural steel designed for bridge engineering, compliant with GB/T 714-2015, offering excellent durability and reliability at 0°C low-temperature environment.
About Q345qC Bridge Steel Plate
Q345qC is a high-strength low-alloy structural steel under Chinese standard (GB/T 714-2015), specially developed for bridge engineering projects in normal temperature environments.
The letter "q" in the grade stands for "qiaoliang" (bridge), and "C" indicates the steel's impact test temperature is 0°C, suitable for bridge construction projects in normal temperature regions of China and worldwide.
This steel features reliable strength (yield strength 345MPa), excellent weldability, and outstanding low-temperature toughness, making it an ideal choice for bridge infrastructure projects in conventional climate zones.
Technical Specifications
Basic Information
Mechanical Properties
| Thickness(mm) | Yield Strength(MPa) ≥ | Tensile Strength(MPa)≥ | Elongation(%) ≥ | Impact Energy(J) ≥ |
|---|---|---|---|---|
| ≤50 | 345 | 490 | 20 | 120 |
| ＞50--≤100 | 335 | 490 | 20 | 120 |
| ＞100--≤150 | 305 | 490 | 20 | 120 |
Chemical Composition (Hot-rolled/Normalized)
| Grade | Quality | C ≤% | Si ≤% | Mn % | Nb % | V % | Ti % | Als % | Cr ≤% | Ni ≤% | Cu ≤% | N ≤% |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q345q | C | 0.18 | 0.55 | 0.90~1.60 | 0.005~0.060 | 0.010~0.080 | 0.006~0.030 | 0.010~0.045 | 0.3 | 0.3 | 0.3 | 0.008 |
a: Al, Nb, V, Ti can be added alone or in combination. Nb+V+Ti ≤ 0.22%.
b: Total aluminum (Alt): 0.015%~0.050%.
Chemical Composition (TMCP)
| Grade | Quality | C ≤% | Si ≤% | Mn % | Nb % | V % | Ti % | Als % | Cr ≤% | Ni ≤% | Cu ≤% | Mo ≤% | N ≤% |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Q345q | C | 0.14 | 0.55 | 0.90~1.60 | 0.010~0.090 | 0.010~0.080 | 0.006~0.030 | 0.010~0.045 | 0.3 | 0.3 | 0.3 | - | 0.008 |
a: Max Mn can be 2.00% by agreement.
b: Al, Nb, V, Ti can be added alone or in combination. Nb+V+Ti ≤ 0.22%.
c: Total aluminum (Alt): 0.015%~0.050%.
International Standard Comparison
Mechanical Properties Comparison (Thickness ≤50mm)
| Property | Q345qC | S355NL | A709 Gr36 |
|---|---|---|---|
| Min Yield Strength (MPa) | 345 | 355 | 250 |
| Tensile Strength (MPa) | 490 | 470-630 | 400-550 |
| Min Elongation (%) | 20 | 22 | 20 |
| Impact Test Temperature (°C) | 0 | -20 | 0 |
Chemical Composition Comparison (%)
| Element | Q345qC | S355NL | A709 Gr36 |
|---|---|---|---|
| Carbon (C) | ≤0.18 | ≤0.22 | ≤0.21 |
| Silicon (Si) | ≤0.55 | ≤0.60 | 0.15-0.40 |
| Manganese (Mn) | 0.90-1.60 | 1.40-1.90 | 0.90-1.60 |
Key Differences Summary:
- Q345qC offers reliable yield strength (345MPa) with excellent 0°C low-temperature toughness
- Designed for bridge projects in normal climate regions
- Excellent weldability with Ceq ≤ 0.42%
- Compliant with GB/T 714-2015 standard
Application Projects
Normal Temperature Highway Bridge
Ideal for medium and small-span highway bridges in normal temperature regions, providing excellent structural stability.
- Plate Thickness: 12mm-50mm
- Total Consumption: 8,600 tons
Normal Area Railway Bridge
Applied to medium-span railway bridges in conventional temperature zones, featuring outstanding fatigue resistance.
- Total Consumption: 12,300 tons
- 50-100 years service life
Urban Viaduct
Used for urban viaducts in conventional temperature regions, offering reliable structural support.
- Plate Thickness: 16mm-60mm
- Excellent structural toughness
Frequently Asked Questions (FAQ)
What is the difference between Q345qC and Q345qD/Q345qE steel plates?
Main differences between Q345qC, Q345qD and Q345qE bridge steel plates:
- Impact Test Temperature: Q345qC (0°C) < Q345qD (-20°C) < Q345qE (-40°C)
- Low-Temperature Performance: Q345qE > Q345qD > Q345qC (higher toughness at lower temperature)
- Application: Q345qC for normal temperature areas, Q345qD for cold areas, Q345qE for extremely cold areas
- Price & Cost: Q345qC is the most cost-effective option for conventional temperature projects
- Impurity Limits: Standard requirements for normal temperature bridge applications
What are the welding requirements for Q345qC steel plates?
Q345qC has excellent weldability (Ceq ≤0.42%) with conventional construction requirements:
- Preheating not required for thickness ≤30mm at ambient temperature ≥0℃
- Preheat to 80-120℃ for thickness >30mm or ambient temperature <0℃
- Use E50 series low-alloy electrodes (E5015/E5016) for conventional welding
- Interpass temperature control ≤250℃ during multi-pass welding
- Post-weld heat treatment not required for general bridge components
- Suitable for welding construction in normal temperature environments
Follow standard welding procedures for Q345 series high-strength structural steels.
What is the operating temperature range of Q345qC steel?
Q345qC is designed for normal temperature environments with the following temperature range:
- Minimum Operating Temperature: 0°C (meets impact energy requirements at this temperature)
- Recommended Continuous Operating Temperature: 0°C ~ 200°C
- Short-term Maximum Operating Temperature: 300°C
- Application Environment: Suitable for normal temperature regions in China and worldwide
- Storage/Transport Temperature: Adaptable to conventional environments
Q345qC is the preferred high-strength bridge steel for conventional climate bridge projects.
What advantages does Q345qC have for normal region bridge construction?
Q345qC has outstanding advantages for normal region bridge construction:
- Excellent toughness: Stable performance at 0°C, preventing brittle fracture
- Reliable strength: 345MPa yield strength meets bridge load-bearing requirements
- Good weldability: Suitable for on-site construction in conventional climates
- Wide application: Ideal for highway, railway, urban bridges in normal temperature regions
- Cost-performance balance: Most economical choice for conventional bridge projects
- National standard certification: Fully compliant with GB/T 714-2015 bridge steel standards
- Stable quality: Mature production process for bridge steel
These advantages make Q345qC the first choice for bridge engineering in conventional climate zones.
What quality inspections are performed for Q345qC steel plates?
Comprehensive quality inspections are provided for Q345qC steel plates:
- EN 10204 3.1 material test certificate with 0°C impact test results
- GB/T 714-2015 bridge steel compliance certification
- 100% ultrasonic testing for internal quality inspection
- Mechanical property test including yield and tensile strength
- 0°C Charpy V-notch impact toughness test report
- Chemical composition analysis in accordance with national standard
- Third-party inspection certification available upon request
All Q345qC steel plates undergo strict quality inspections to ensure engineering compliance.
Core Advantages
0℃ Temperature Toughness
Outstanding performance in conventional climate environments.
Excellent Weldability
Optimized carbon equivalent ensures easy welding.
Cost-Effective
Perfect economic choice for conventional bridge projects.
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