1. Hot-Rolled Weathering Steel Plates: Mainstream Delivery Form
Production Process: Plates are rolled at high temperatures (above the steel's recrystallization temperature, ~900–1100°C), which improves the steel's ductility and formability, making it easy to process (laser cutting, welding, bending).
Key Characteristics:
Thickness range: 3–100 mm (covers most application needs, from decorative panels to heavy structural components).
Surface finish: Has a natural, slightly rough oxide scale (mill scale) on the surface, which is the base for patina formation.
Cost-effectiveness: Hot rolling is a high-efficiency, low-cost process, making it the preferred choice for bulk orders of weathering steel plates.
Common Grades: Q355NH, SPA-H, Corten A/B, ASTM A588-all are mainly supplied as hot-rolled plates.
2. Cold-Rolled Weathering Steel Plates: Specialized Delivery Form
Production Process: Plates are rolled at room temperature after hot rolling, which further refines the grain structure and improves surface smoothness and dimensional accuracy.
Key Characteristics:
Thickness range: 0.5–3 mm (limited to thin-gauge products, suitable for lightweight decorative parts like small signs or precision components).
Surface finish: Smooth, clean, and oxide-free, with better flatness than hot-rolled plates. However, the cold rolling process introduces residual stress, which may require annealing for high-precision applications.
Higher cost: Cold rolling involves more processing steps, so the price is significantly higher than hot-rolled plates.
Application Scenarios: Only used when thin thickness, high surface quality, or precise dimensional tolerance are required (e.g., decorative nameplates, small laser-cut patterns).
3. Key Notes for Delivery Status Selection
For most weathering steel applications (scenic guide signs, flower beds, hollow partitions, welding components), hot-rolled plates are sufficient and cost-effective.
Cold-rolled plates are not recommended for structural welding or outdoor applications requiring thick patina layers-their smooth surface slows down natural patina formation, and residual stress may cause warping during processing.
Both hot-rolled and cold-rolled weathering steel plates can be processed with artificial patina acceleration to achieve the desired rusty aesthetic.
