Processing performance of SPA-C weathering steel plate

SPA-C steel plate is a weather-resistant structural steel that complies with the Japanese JIS G3125 standard, offering excellent corrosion resistance and weathering performance.

Its alloy composition includes appropriate amounts of copper (Cu), chromium (Cr), and nickel (Ni), which form a dense and stable "rust layer (patina)" on the steel surface when exposed to the atmosphere over time. This layer effectively blocks the further penetration of external moisture, salt fog, and corrosive agents.

Compared to ordinary carbon steel, the corrosion rate of SPA-C can be reduced by 6–8 times. In atmospheric environments, it does not require frequent repainting, and its service life can be extended to 20–40 years, significantly reducing maintenance and upkeep costs.

Weather Resistance

Corrosion rate reduced by 6–8 times compared to ordinary Q235 carbon steel.

Can be used for 20–30 years in moderate industrial atmospheric or coastal environments, and over 40 years in general atmospheric environments.

Yield strength ≥ 245 MPa

Tensile strength: 400–550 MPa

Elongation: ≥ 21%

Weld joint strength can reach over 95% of the base material, ensuring structural safety.

Welding Performance: SPA-C weathering steel is suitable for arc welding, gas shielded welding, submerged arc welding, and other methods, without requiring special welding materials. In actual engineering applications, the corrosion resistance of the weld seam is comparable to that of the base material.

Machining Performance: The hardness is slightly higher than that of ordinary carbon steel. It is recommended to use high-speed steel or carbide tools, and to reasonably control the cutting speed and feed rate to improve processing efficiency and surface quality.

Bending Performance: It can be cold-bent or hot-bent. For common plate thicknesses (6–16 mm), a minimum bending radius of 2–3 times the plate thickness is recommended during cold bending to prevent cracking.

Surface Treatment: Secondary protective treatments such as shot blasting, coating, or galvanizing can be applied to further extend corrosion resistance by 10–20 years.

Hot working performance: It exhibits good plasticity within the temperature range of 800–1200°C, enabling hot rolling or forging processes.

Cold working performance: Cold working performance is generally poor, with a tendency to crack. If significant cold deformation is required, appropriate annealing heat treatment should be performed beforehand.

• Bridge and Railway Engineering: Used for main beams, bridge decks, and guardrails to ensure long-term load-bearing capacity and reduce corrosion maintenance.

• Building Facades and Decorations: Used for curtain walls, roofs, balcony railings, etc., with a naturally formed rust-red layer that combines protection and aesthetics.

• Containers and Mechanical Structural Components: Used for containers, vehicle chassis, and mechanical frames, combining high strength and corrosion resistance.

• Landscape Architecture and Sculpture: The natural rust color harmonizes with the environment, making it suitable for outdoor sculptures and landscape decorations.

• Port and Marine Engineering: Suitable for piers, jetties, and marine platforms, withstanding salt fog and humid environments.

With years of export experience, Gnee understands international standards and buyer needs. We offer complete overseas supply solutions – from design to delivery – and support various trade terms including FOB, CIF, and DDP.

You will benefit from:

 Fast sampling and competitive quotations

 Professional export packaging and container loading plans

 Third-party inspection and mill certificates available

 Full English service and real-time order tracking

 Custom labeling and neutral/personalized branding support

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