Q460NH is a high‑strength weathering steel; its biggest difference from ordinary weathering steels (Q235NH/Q355NH) is higher strength, while corrosion resistance is similar; compared with imported grades (A588/S355J0WP), it is stronger but less optimized for patina.
1. Strength level (the biggest difference)
Q460NH: Yield strength ≥ 460 MPa
Q355NH / S355J0WP / A588: ≥ 355 MPa
Q235NH: ≥ 235 MPa
→ Under the same load, Q460NH can use thinner plates / smaller sections to reduce structural weight.
2. Corrosion resistance
Q460NH ≈ Q355NH ≈ S355J0WP ≈ A588
All rely on Cu‑Cr‑Ni‑P alloy to form protective patina
No obvious difference in normal atmospheric environment
All perform poorly in high salt, high humidity, submerged conditions
3. Chemical composition
Q460NH has higher C, Mn, Nb, V, Ti to achieve high strength
Weathering alloy elements (Cu, Cr, Ni, P) are basically the same as Q355NH
S355J0WP has higher P for faster, denser patina
4. Weldability & toughness
Q460NH has slightly higher carbon equivalent → slightly worse weldability
Thicker plates or low temperatures need preheating
Q355NH / S355J0WP: better weldability, less preheat needed
Toughness at low temperature is generally lower than Q355NH
5. Surface patina & color
Patina formation speed and final color are similar to Q355NH
Not as fast as high‑P S355J0WP
Surface texture and rust change process are basically the same
6. Applications
Q460NH:High‑rise structures, long‑span bridges, heavy machinery, crane booms, mining equipment, large steel towers
Q355NH / S355J0WP:General buildings, containers, bridges, landscape facades, ordinary steel structures
Q235NH:Lightweight non‑load‑bearing parts, simple structures
