Q345 Galvanized steel plate is a high-strength, low-alloy (HSLA) structural steel that has been hot-dipped in a bath of molten zinc. This process combines the exceptional mechanical properties of Q345 grade steel with the superior corrosion protection of a zinc coating. It is an ideal material for applications demanding durability, longevity, and structural integrity in harsh environments.

This product conforms to the Chinese GB/T 1591 standard for the base material (Q345) and typically follows GB/T 13912 or international equivalents like ASTM A123 for the hot-dip galvanizing process. The Q345 grade is broadly equivalent to ASTM A572 Grade 50 or S355JR under EN 10025-2 standards.

Key Features & Advantages

Exceptional Corrosion Resistance: The zinc coating acts as a robust physical barrier against moisture, chemicals, and other corrosive elements. It also provides cathodic (sacrificial) protection, meaning the zinc layer will corrode before the underlying steel, even if the coating is scratched or damaged.

High Strength and Load-Bearing Capacity: As an HSLA steel, Q345 offers an excellent strength-to-weight ratio. Its minimum yield strength of 345 MPa (or 50 ksi, equivalent to A572 Gr. 50) allows for the design of strong, reliable structures while potentially reducing material thickness and weight.

Long Service Life: Galvanization significantly extends the service life of steel components, often for several decades without the need for maintenance, even in industrial or coastal atmospheres. This reduces long-term maintenance and replacement costs.

Excellent Durability and Toughness: The base Q345 steel provides good impact resistance and toughness, making it suitable for structures that must withstand dynamic loads, vibrations, and variable stress.

Versatile Formability and Weldability: Despite its high strength, Q345 Galvanized plate retains good formability for bending and shaping. It can also be welded using standard procedures, though precautions must be taken to manage zinc fumes.

Protective Coating Adhesion: The hot-dip process creates a metallurgical bond between the zinc and the steel, resulting in a coating that is tough, uniform, and resistant to handling damage during fabrication and transport.

Cost-Effectiveness: By offering a long lifespan with minimal upkeep, Q345 galvanized steel provides an outstanding return on investment over the lifetime of a project.

Applications

Q345 Galvanized Steel Plate is widely used across numerous industries, including:

Construction & Infrastructure: Structural beams, trusses, building frames, purlins, and roofing supports.

Transportation: Truck trailers, bus frames, shipping containers, and heavy-duty vehicle parts.

Power & Energy: Transmission towers, electrical substations, and support structures for solar and wind farms.

Agricultural Machinery: Grain silos, equipment frames, and storage facilities.

Manufacturing: Factory flooring, conveyor systems, shelving, and heavy-duty storage racks.

Bridge Components: Guardrails, walkways, and support elements.

Available Specifications

Standard: GB/T 1591 (Q345B), GB/T 13912 / ASTM A123 (Galvanizing)

Grade: Q345A, Q345B, Q345C, Q345D, Q345E (differing impact toughness at low temperatures)

Thickness: 1.0mm - 100mm (Custom ranges available)

Width: 1000mm - 2500mm (Custom ranges available)

Zinc Coating Mass: 60 g/m² to 600 g/m² (Z60 to Z600), with common coatings being Z120 (G90), Z180 (G115), and Z275.

Surface Treatment: Regular spangle, minimal spangle, or smooth surface finish.