Q345qC High Strength Bridge Steel Plate for Bridge Construction & Infrastructure Projects
GB/T 714 Standard 345 MPa Yield Strength Steel with Excellent Weldability & Low-Temperature Toughness
Overview
Q345qC is a high-quality bridge construction steel plate manufactured according to the Chinese national standard GB/T 714 "Steel Plates for Bridge Structures". It is specifically designed for large-span bridges, highway bridges, railway bridges, and other infrastructure projects requiring excellent weldability, low-temperature toughness, and fatigue resistance.
This steel grade is the most commonly used material in Chinese bridge construction due to its optimal balance of strength (345 MPa minimum yield strength), toughness (tested at 0°C), and excellent weldability. The "C" quality grade ensures reliable performance in demanding bridge applications with stringent safety requirements.
Definition and Naming Logic
The designation Q345qC follows the Chinese standard GB/T 714 naming system for bridge steel plates.
Its logical structure is: 1 letter + 3 digits + 1 letter + 1 letter
First letter (Q):Chinese pinyin "Qu" for yield strength (屈)
Second letter (q):Chinese pinyin "qiao" for bridge (桥)
Third letter (C):Quality grade C, impact tested at 0°C
Code Interpretation
Therefore, when treating Q345qC as a code, the correct and complete deciphering is:
"A bridge construction steel with minimum yield strength of 345 MPa, impact tested at 0°C, offering excellent weldability and low-temperature toughness for infrastructure projects."
Value Proposition
Q345qC bridge steel represents the optimal balance between performance and cost-effectiveness for bridge construction. As professional Chinese steel suppliers, we provide this GB/T 714 certified material with full traceability, quality assurance, and competitive pricing for global infrastructure projects.
We are a Chinese supplier offering Q345qC bridge steel plates in spot supply and mill-direct ordering services, with full export service capabilities.
We have supplied materials for numerous bridge projects and understand the specific requirements of bridge construction applications.
Start Your Q345qC Procurement
We provide two procurement options for Q345qC bridge steel plates, so you can choose the most cost-effective solution for your project. Backed by competitive prices, strict quality control, and on-time delivery, we make sourcing simple and reliable.
Q345qC bridge steel plates are manufactured according to strict international and national standards, ensuring global acceptance for bridge construction and infrastructure projects.
GB/T
GB/T 714 Standard
China Bridge Steel Standard
EN
EN 10025
European Structural Steel
ASTM
ASTM A709
US Bridge Steel
JIS
JIS G3106
Japanese Welded Structure
ISO
ISO 630
Structural Steels
DIN
DIN EN 10025
German Structural Steel
Note: Q345qC is equivalent to various international standards including EN 10025-2 S355K2, ASTM A709 Grade 50, JIS SM490B, and DIN EN 10025-2 S355J2. Material test certificates confirm compliance with specific project requirements.
2. Key Advantages of Q345qC Bridge Steel Grade
Steel Grade
High Strength & Stiffness
Excellent Weldability
Low-Temperature Toughness
Fatigue Resistance
Q345qC Bridge Steel
345 MPa minimum yield strength provides optimal structural stiffness and load-bearing capacity for long-span bridge construction
Low carbon equivalent (CEV ≤ 0.44) ensures excellent weldability with reduced preheating requirements for field welding
Impact toughness tested at 0°C (120 J minimum) ensures reliable performance in cold climate bridge applications
Specifically designed for dynamic loading conditions with excellent fatigue resistance for long service life
3. Chemical Composition & Mechanical Properties of Q345qC Steel
Chemical Composition (Quality Grade C, %)
C Carbon
Si Silicon
Mn Manganese
P Phosphorus
S Sulfur
Nb Niobium
V Vanadium
Al Aluminum
≤0.18
≤0.55
0.90~1.60
≤0.030
≤0.025
0.005~0.060
0.010~0.080
≥0.010
* Chemical composition according to GB/T 714-2015 standard for hot-rolled or normalized steel. Ti content: 0.006~0.030%. Total microalloying elements (Nb+V+Ti) ≤ 0.22%.
Mechanical Properties of Q345qC Steel
Thickness (mm)
Yield Strength (MPa)
Tensile Strength (MPa)
Elongation (%)
Impact Test
≤50 mm
≥345 MPa
≥490 MPa
≥20%
0°C, ≥120J
50~100 mm
≥335 MPa
≥490 MPa
≥20%
0°C, ≥120J
100~150 mm
≥305 MPa
≥490 MPa
≥20%
0°C, ≥120J
4. Q345q Bridge Steel: Quality Grade Comparison for Different Temperature Requirements
The following table compares different quality grades within the Q345q bridge steel series. All grades share the same minimum yield strength (≥345 MPa) but are designed for different service temperatures and impact toughness requirements.
Comparison of Q345q Bridge Steel Quality Grades for Different Temperature Requirements
Steel Grade
Impact Test Temperature
Min. Impact Energy
Typical Application Environment
Q345qC
0°C
≥ 120 J
Recommended choice for general bridge construction in temperate climate zones, standard highway and railway bridges, offering optimal balance of strength and toughness
Q345qD
-20°C
≥ 120 J
For bridge construction in cold climate regions, bridges in northern China, Russia, Canada, Northern Europe
Q345qE
-40°C
≥ 120 J
For bridges in extremely cold regions, arctic bridge construction, critical infrastructure in severe cold environments
5. 345-Class Bridge Steel: Strength Grade Comparison for Different Load Requirements
This table compares different strength grades within the 345 Class bridge steel series. All grades share similar chemical composition and quality grades but offer different yield strengths for varying load requirements.
Comparison of 345-Class Bridge Steel Strength Grades for Different Load Requirements
Steel Grade
Yield Strength (Minimum)
Tensile Strength (Minimum)
Key Selection Insight
Standard Strength
Q345qC
≥ 345 MPa
Most commonly used for general bridge construction, highway bridges, railway bridges. Optimal balance of strength, weldability, and cost-effectiveness.
Medium-High Strength
Q370qC
≥ 370 MPa
For medium-span bridges with higher load requirements, coastal bridges, bridges in seismic zones
High Strength
Q420qC
≥ 420 MPa
For long-span bridges, cable-stayed bridges, suspension bridges, and special bridge structures requiring high strength-to-weight ratio
Choose Your Optimal Bridge Steel Grade
Compare key specifications across similar grades. Varying parameters are highlighted for quick decision-making.
6. Typical Applications of Q345qC Bridge Steel Plate
Highway Bridge Girders & Beams
Q345qC steel plates are the primary material for constructing main girders and beams in highway bridges. Their 345 MPa minimum yield strength provides excellent load-bearing capacity while maintaining optimal stiffness for long-span bridge applications. The excellent weldability ensures efficient on-site construction and assembly.
Railway Bridges
For railway bridge construction, Q345qC provides the necessary fatigue resistance and dynamic load capacity required for heavy rail traffic. The material's 0°C impact toughness ensures reliable performance under varying temperature conditions, making it suitable for railway bridges in temperate climate zones.
Urban Overpasses & Interchanges
A wide range of urban overpasses and interchange structures utilize Q345qC due to its excellent weldability and formability. This combination is essential for complex urban bridge designs that require precise fabrication and efficient construction timelines, while maintaining structural integrity under urban traffic loads.
Bridge Support Structures
The optimal strength-to-toughness ratio of Q345qC bridge steel is critical for bridge piers, abutments, and support systems. It provides reliable performance under compression and shear loads while offering excellent weldability for connecting to other bridge components. The 0°C impact toughness ensures durability in temperate climate applications.
Bridge Rehabilitation & Strengthening
Bridge rehabilitation and strengthening projects frequently utilize Q345qC steel for replacing deteriorated sections or adding reinforcement. Its compatibility with existing structures and excellent weldability make it ideal for repair applications, extending the service life of aging bridges while maintaining structural performance standards.
Infrastructure Projects
Beyond bridges, Q345qC is also suitable for other infrastructure projects requiring structural steel with good weldability and toughness. This includes pedestrian bridges, culverts, industrial structures, and marine construction where the combination of strength and durability is essential for long-term performance.
7. Available Sizes & Supply Conditions for Q345qC Steel Plate
9. Why Choose CEHE Steel for Your Bridge Steel Needs?
Discover how our expertise, resources, and commitment make us the preferred partner for bridge steel solutions worldwide.
Bridge Steel Specialization and Technical Expertise
We specialize in bridge construction steels with deep understanding of GB/T 714, ASTM A709, EN 10025 standards. Our technical team provides guidance on material selection, welding procedures, and fabrication requirements specific to bridge applications.
Bridge Standards Expertise
GB/T 714, ASTM A709, EN 10025, JIS G3106 standards compliance
Supplied materials for highway, railway, and urban bridge projects
Quality Specifications
Customized to meet specific bridge design and safety requirements
Comprehensive Quality System for Bridge Applications
We implement stringent quality control specific to bridge steel requirements, ensuring every Q345qC plate meets the exacting standards for structural integrity, weldability, and long-term performance in bridge applications.
Full Certification
GB/T 714 compliance with complete mill test certificates
Impact Testing
0°C Charpy V-notch testing with 120J minimum requirement
Complete Traceability
Heat number tracking from production to project installation
Quality Standards
EN 10204 3.1/3.2 certificates with international acceptance
Flexible Supply Chain & Custom Solutions
We provide tailored bridge steel solutions with flexible sizing, processing options, and supply chain management to meet specific project requirements and construction timelines.
Spot availability and mill-direct ordering with competitive lead times
Project Coordination
Supply chain management aligned with construction schedules
Proven Bridge Project Experience Since 2009
Since our founding in 2009, we have supplied Q345qC and other bridge steels for numerous infrastructure projects worldwide, building expertise in bridge construction requirements and material specifications.
Industry Experience
Specialized in structural and bridge steels since 2009
Project Portfolio
Supplied materials for highway, railway, and urban bridge projects globally
Client Relationships
Long-term partnerships with bridge contractors and construction firms
Technical Validation
Materials validated through successful bridge construction projects
10. Frequently Asked Questions
Q345qC is primarily used for bridge construction applications including highway bridge girders, railway bridges, urban overpasses, and bridge support structures. It is the most commonly used bridge steel grade in China according to GB/T 714 standard, offering 345 MPa minimum yield strength and excellent weldability with 0°C impact toughness.
The main difference is yield strength. Both Q235qC and Q345qC are impact tested at 0°C, but Q235qC has a minimum yield strength of 235 MPa, while Q345qC has a higher minimum yield strength of 345 MPa. Q345qC provides approximately 47% higher load-bearing capacity, making it suitable for more demanding bridge applications requiring greater structural strength.
Q345qC is impact tested at 0°C (32°F) in accordance with GB/T 714-2015 standard requirements for quality grade C bridge steel. The minimum impact energy requirement is 120 Joules for Charpy V-notch testing at this temperature.
We provide GB/T 714 standard mill test certificates along with EN 10204 3.1 certificates for international projects. Each shipment includes documentation for chemical composition, mechanical properties (including 0°C impact testing), and ultrasonic testing results when required.
Q345qC is equivalent to several international standards: EN 10025-2 S355K2 (European standard), ASTM A709 Grade 50 (US bridge steel standard), JIS SM490B (Japanese standard), and DIN EN 10025-2 S355J2 (German standard). We can provide materials certified to these equivalent standards upon request.
Q345qC has excellent weldability due to its controlled chemical composition with low carbon equivalent (CEV typically ≤ 0.44). This allows for welding without preheating in most thicknesses under normal conditions. For thicknesses above 40mm or in cold environments, mild preheating (100-150°C) is recommended. All common welding methods including SMAW, GMAW, SAW, and FCAW can be used.
Yes, we specialize in customized solutions for bridge construction. We can supply Q345qC plates according to your specified dimensions (thickness 6-150mm, width 1600-4500mm, length 4000-18000mm). Additional processing services include cutting to size, edge preparation (beveling), surface blasting, and priming. We also provide EN 10204 3.2 certificates for international projects.
Delivery time for customized orders: Approximately 20-30 days for hot-rolled plates and 40-60 days for normalized plates, depending on specifications and quantity.
We offer flexible MOQ options for bridge steel projects. For standard Q345qC plates, typical lead time is 20-30 days for hot-rolled condition and 40-60 days for normalized condition. We understand bridge project requirements and can work with project-specific quantities. For urgent requirements, we maintain strategic inventory of common sizes and can arrange expedited delivery.
The price of Q345qC steel plate depends on thickness, dimensions, quantity, delivery condition (hot-rolled or normalized), surface treatment, and market conditions. Q345qC typically commands a moderate premium over Q235qC due to its higher strength. For accurate pricing, please contact our sales team with your specific requirements including grade, size, quantity, delivery condition, destination, and any special processing needs. We provide competitive quotations within 24 hours.
We offer various surface treatment options for Q345qC bridge steel plates: 1) As-rolled condition (mill surface), 2) Shot blasted to Sa 2.5 cleanliness, 3) Primed with shop primer (typically inorganic zinc silicate for bridge applications), 4) Beveled edges for welding preparation. Surface treatment can be customized according to your project specifications and painting requirements. Proper surface preparation is essential for long-term corrosion protection in bridge applications.
11. Information You May Find Relevant
Pricing Factors for Q345qC Bridge Steel
Pricing for Q345qC bridge steel is typically based on several key factors: 1) Thickness range (6-150mm with different pricing tiers), 2) Width and length requirements (standard vs. special sizes), 3) Delivery condition (hot-rolled, normalized, or TMCP), 4) Quantity (volume discounts available), 5) Surface treatment (as-rolled, blasted, or primed), 6) Certification requirements (standard mill certs vs. third-party inspection). Prices are typically quoted per metric ton (1000kg) with additional charges for processing services like cutting, beveling, or special packaging for export.
Request Technical & Commercial Support
We supply GB/T 714 certified Q345qC bridge construction steel plate with 345 MPa yield strength, 0°C impact toughness, excellent weldability, full traceability, and coordinated logistics support for bridge projects worldwide.
Response Time: We typically respond to all inquiries within 24 hours
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