High-Strength Low-Alloy Structural Steel: Optimized for Heavy Load & Corrosion Resistance
This advanced low-alloy steel combines controlled chemical composition with tiered mechanical performance, ideal for structural components in construction, energy, and transport sectors.
Chemical Composition & Material Design
Engineered for weldability and environmental durability, the alloy features precise impurity control:
- Sulfur (S): ≤0.025% (enhances machinability and hot workability)
- Nitrogen (N): ≤0.2% (improves austenite stabilization)
- Aluminum (Al): ≤0.2% (grain refinement agent)
- Chromium (Cr): ≤0.3% (oxidation resistance)
- Copper (Cu): ≤0.2% (atmospheric corrosion shielding)
- Molybdenum (Mo): ≤0.1% (elevated-temperature strength)
- Nickel (Ni): ≤1.0% (low-temperature toughness enhancer)
- Niobium (Nb): ≤0.05% (precipitation hardening)
Certification: ASTM A6/A6M-22 compliant with full traceability
Mechanical Properties by Thickness
Tailored strength gradients ensure optimal load distribution across structural profiles:
| Thickness (mm) | Tensile (MPa) | Yield (MPa) | Elongation (%) |
|---|---|---|---|
| ≤20 | 500-650 | ≥380 | ≥20 |
| 21-40 | 490-640 | ≥375 | ≥19 |
| 41-60 | 480-630 | ≥365 | ≥18 |
| 61-80 | 470-620 | ≥355 | ≥17 |
| 81-100 | 460-610 | ≥345 | ≥16 |
Test standards: ASTM E8/E8M (tensile), ISO 6892-1 (yield), EN ISO 2566-1 (elongation)
Key Performance Features
- Weld Efficiency
- Pcm ≤0.22% enables crack-free welding without preheat below 25mm thickness
- 87% joint efficiency with E7018 electrodes (AWS D1.1 compliant)
- Environmental Resistance
- 0.035 mm/year corrosion rate in industrial atmospheres (ISO 9223 C3 class)
- 40% better pitting resistance vs. S355J0 in coastal environments
- Cost Efficiency
- 18% weight reduction compared to Q345B at equivalent strength
- 25% lower fabrication costs than A572 Gr.50 through reduced machining time
Industrial Applications
- Construction: Bridge girders (60mm) with 650 MPa cyclic load capacity
- Energy: Wind turbine base rings (80mm) in -30°C environments
- Transport: Mining truck chassis (50mm) resisting 500 MPa impact loads
- Manufacturing: Hydraulic press frames (100mm) at 300°C service temps
Processing Guidelines
Heat Treatment:
- Normalizing: 890-920°C × 1.5 mins/mm → forced air cooling
- Stress Relieving: 580-620°C × 2 mins/mm for dimensional stability
Machining Parameters:
| Operation | Speed | Feed | Tool Type |
|---|---|---|---|
| Drilling | 30-40 m/min | 0.12 mm/rev | TiN-coated HSS |
| Grinding | 25-35 m/s | 0.02 mm/pass | CBN abrasive wheels |
Packaging: VCI-coated + edge protectors; 20-ton container loading capacity
Lead Time: 6-8 weeks for custom-cut plates (plasma/waterjet options available)
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G90 Galvanized Sheet supplier
Luo Kaiwei Steel Company is a comprehensive steel supplier that produces a variety of carbon steel plates, carbon steel pipes, galvanized steel, carbon steel coils, and steel profiles.
