S355J5W Structural Plate -50℃ Impact for Bridges is a premium-grade structural steel compliant with EN 10025-5, specifically designed for bridge construction and other critical outdoor infrastructure requiring exceptional strength, cold-temperature toughness, and atmospheric corrosion resistance. The designation "S355" indicates a minimum yield strength of 355 MPa (for thickness ≤16mm), ensuring robust load-bearing capacity, while "J5" confirms reliable impact resistance at -50℃, a critical feature for bridges in frigid climates or regions with extreme temperature fluctuations. The "W" denotes its weathering capability, achieved through strategic alloying with copper (Cu), phosphorus (P), chromium (Cr), and nickel (Ni). These elements form a dense, adherent oxide layer that acts as a natural barrier, reducing corrosion rates by 2–8 times compared to conventional steel and minimizing the need for frequent protective coatings.
Mechanically, the plate offers a tensile strength range of 490–630 MPa and an elongation rate of ≥21%, balancing structural integrity with formability for welding and fabrication. Its -50℃ impact resistance (typically ≥27J in longitudinal tests) ensures resistance to brittle fracture in freezing conditions, making it suitable for long-span bridges, railway overpasses, or coastal bridge structures exposed to harsh weather. The weathering property excels in industrial zones, marine environments, or humid regions, where salt, pollution, or moisture accelerate corrosion in standard steel.
Beyond bridges, this plate is widely used in transmission towers, container cranes, and railway carriages, prioritizing durability and low maintenance. While originally defined in EN 10025-5:2004, users should verify compliance with the latest standard (e.g., EN 10025-5:2024), as newer grades like S355K2W (with -40℃ impact) may serve as alternatives based on project specifications. Supplied in hot-rolled, normalized, or normalized-rolled conditions, S355J5W ensures versatility in engineering applications. Internationally, it aligns with equivalents such as China's Q355NHJ5W and the U.S. A588 Grade K, making it a trusted choice for global bridge projects demanding long-term reliability and cost-efficient corrosion resistance.
FAQ
Q: What is the primary standard for S355J5W?
A: EN 10025-5, specifying weathering structural steel.
Q: At what temperature does it maintain impact resistance?
A: -50℃, suitable for bridges in extremely cold regions.
Q: How does it protect against corrosion?
A: Alloy elements (Cu, Cr, Ni) form a protective rust layer to slow atmospheric corrosion.
Q: What is its minimum yield strength?
A: 355 MPa for thicknesses up to 16mm.
Q: Are there equivalent grades for international projects?
A: Yes, e.g., China's Q355NHJ5W and US A588 Grade K.
