Chemical Composition and Mechanical Properties of ASTM A588 Grade A Steel
ASTM A588 Grade A is a high-strength low-alloy structural steel with the following composition and properties:
| Element | Percentage |
|---|---|
| C | 0.19% max |
| Si | 0.30-0.65% |
| Mn | 0.80-1.25% |
| P | 0.04% max |
| S | 0.05% max |
| Cu | 0.25-0.40% |
| Cr | 0.40-0.65% |
| Ni | 0.40% max |
| V | 0.02-0.10% |
Mechanical Properties:
| Property | Value |
|---|---|
| Yield Strength (min) | 345 MPa (50 ksi) |
| Tensile Strength | 485 MPa (70 ksi) min |
| Elongation in 50mm (2″) | 21% min |
Applications and Uses of ASTM A588 Grade A in Construction
ASTM A588 Grade A steel is commonly used in:
- Bridge construction (girders, components)
- Building structures
- Transmission towers
- Highway poles
- Railcars and containers
- Outdoor sculptures
Its high strength and corrosion resistance make it ideal for structures exposed to atmospheric conditions.
Corrosion Resistance and Weathering Characteristics
ASTM A588 Grade A exhibits superior corrosion resistance compared to regular carbon steel. It forms a protective oxide film that slows down further corrosion, making it suitable for unpainted applications. The atmospheric corrosion resistance index (ASTM G101) must be ≥6.0.
Manufacturing Process and Available Dimensions
ASTM A588 Grade A steel is typically produced through hot rolling. Available dimensions may vary, but common ranges include:
- Thickness: 6mm to 200mm
- Width: 1500mm to 4050mm
- Length: 3000mm to 15000mm
Comparison of ASTM A588 Grade A with Other Steel Grades
| Grade | Yield Strength (min) | Corrosion Resistance |
|---|---|---|
| A588 Grade A | 345 MPa (50 ksi) | Excellent |
| A36 | 250 MPa (36 ksi) | Standard |
| A572 Grade 50 | 345 MPa (50 ksi) | Good |
Welding and Fabrication Considerations
ASTM A588 Grade A can be welded using standard welding techniques. However, care should be taken to maintain its corrosion-resistant properties in the heat-affected zones.
