Q310GNH High Strength Weathering Steel Plate is a premium structural steel grade compliant with GB/T 4171-2008, engineered to deliver exceptional atmospheric corrosion resistance and mechanical performance. This alloy is ideal for applications requiring long-term durability in harsh environments, such as bridges, industrial equipment, and architectural structures. With a yield strength of ≥310 MPa and a tensile strength of ≥450 MPa, it offers a robust balance of strength and corrosion resistance, reducing maintenance costs while extending service life.
Technical Properties
Chemical Composition
Cu-P-Cr-Ni Alloy System: Microalloyed with copper (Cu), phosphorus (P), chromium (Cr), and nickel (Ni) to form a dense, adherent rust layer (γ-FeOOH) that inhibits further corrosion.
Low Carbon (C ≤0.12%): Ensures excellent weldability and ductility.
Strict Sulfur Control (S ≤0.02%): Minimizes hot brittleness and enhances toughness.
Mechanical Performance
Yield Strength ≥310 MPa: Suitable for medium- to high-load structural applications.
Elongation ≥22%: Provides flexibility for complex forming processes like bending and rolling.
Impact Resistance: Achieves ≥34 J at room temperature (V-notch), with optional -20℃ impact testing available.
Corrosion Resistance
Self-Protective Patina: Over 3–6 months, a stable rust layer (50–100 μm thick) forms, reducing annual corrosion rates to 0.01–0.02 mm-1/5 to 1/8 that of carbon steel.
High Weathering Index (I ≥6.0): Calculated as I = 26.01Cu + 3.88P + 1.20Cr + 1.49Ni, exceeding industry standards for atmospheric durability.
FAQ
1. What is Q310GNH High Strength Weathering Steel Plate designed for?
Answer: It is designed for applications requiring long-term durability in harsh environments, such as bridges, industrial equipment, and architectural structures, combining high strength with exceptional atmospheric corrosion resistance.
2. Which standard does Q310GNH comply with?
Answer: It complies with GB/T 4171-2008.
3. What are the key mechanical properties of Q310GNH steel plates?
Answer:
Yield strength: ≥310 MPa (suitable for medium-to-high-load structural applications).
Tensile strength: ≥450 MPa.
Elongation: ≥22% (enables complex forming via bending/rolling).
Impact resistance: ≥34 J at room temperature (V-notch), with optional -20°C testing available.
4. How does Q310GNH enhance corrosion resistance?
Answer:
Self-protective patina (γ-FeOOH): Forms a 50–100 μm dense rust layer over 3–6 months, reducing annual corrosion rates to 0.01–0.02 mm (1/5 to 1/8 that of carbon steel).
Cu-P-Cr-Ni alloy system: Copper, phosphorus, chromium, and nickel collaborate to create a protective oxide layer, with a weathering index (I ≥6.0) exceeding industry standards.
5. What technical advantages does Q310GNH offer for structural applications?
Answer:
Low carbon content (C ≤0.12%): Ensures excellent weldability and ductility for complex fabrications.
Strict sulfur control (S ≤0.02%): Minimizes hot brittleness and enhances toughness for dynamic loads.
Lifecycle cost savings: Reduces maintenance needs and extends service life, offering a robust balance of strength and corrosion resistance.
