ASTM A572
Basic Info
The ASTM A572 standard specifies the standard specifications for high-strength low alloy structural steel used in buildings, bridges, machinery, and other structures. These steels have excellent weldability and mechanical properties, and are widely used in various engineering applications. This standard covers the chemical composition, mechanical properties, and dimensional requirements of steel, ensuring that the product meets the requirements of engineering design and meets quality standards.
Characteristics
High Strength: ASTM A572 steel exhibits high strength properties, with minimum yield strength ranging from 50 ksi (345 MPa) to 65 ksi (450 MPa) depending on the grade. This makes it suitable for load-bearing structures and heavy-duty applications.
Low Alloy Composition: ASTM A572 is a low-alloy steel, meaning it contains alloying elements such as manganese, phosphorus, sulfur, silicon, and copper in addition to iron. These alloying elements contribute to the material’s strength and improve its mechanical properties.
Excellent Weldability: ASTM A572 steel is known for its excellent weldability, allowing for easy fabrication and assembly using common welding techniques such as arc welding, gas welding, and resistance welding. This makes it versatile for various structural applications.
Cost-Effective: Despite its superior mechanical properties, ASTM A572 steel is cost-effective compared to some other high-strength steel grades, making it a popular choice for structural applications where strength and economy are both important considerations.
ASTM A572 Data Sheet
Steel Grade
Dimensions and Tolerances
Equivalent Steel Grades
Chemical Composition
Mechanical Properties
Fabrication and Welding
Steel Grade
ASTM A352 Grade 40:
- Yield Strength: 40 ksi
- Tensile Strength: 65-85 ksi
- Elongation in 2″: 20%
- Charpy V-Notch Impact Test: 20 min at -30°C (-22°F)
ASTM A352 Grade 50:
- Yield Strength: 50 ksi
- Tensile Strength: 70-95 ksi
- Elongation in 2″: 18%
- Charpy V-Notch Impact Test: 18 min at -30°C (-22°F)
ASTM A352 Grade 55:
- Yield Strength: 55 ksi
- Tensile Strength: 75-95 ksi
- Elongation in 2″: 17%
- Charpy V-Notch Impact Test: 15 min at -30°C (-22°F)
ASTM A352 Grade 65:
- Yield Strength: 65 ksi
- Tensile Strength: 80-105 ksi
- Elongation in 2″: 15%
- Charpy V-Notch Impact Test: 15 min at -30°C (-22°F)
Dimensions and Tolerances
- Shape: Plates, sheets, bars, beams, channels, angles, and structural sections.
- Width: Up to 96 inches (2438 mm) for plates and sheets; various widths for other shapes.
- Thickness: 1/4 inch (6.35 mm) to 4 inches (101.6 mm) for plates and sheets; various thicknesses for other shapes.
- Length: Up to 480 inches (12,192 mm) for plates and sheets; various lengths for other shapes.
- Tolerance Width: Standard mill tolerances apply.
- Tolerance Length: Standard mill tolerances apply.
- Tolerance Thickness: Standard mill tolerances apply.
- Flatness: As specified in ASTM A6/A6M.
- Surface Finish: As specified in ASTM A6/A6M.
Equivalent Steel Grades
United States:
- Equivalent Grade: ASTM A572 Grade 50
- Standard: ASTM A572
- Notes: Widely used structural steel grade with excellent mechanical properties.
European Union:
- Equivalent Grade: S355JR, S355J0, S355J2
- Standard: EN 10025-2
- Notes: European standard equivalent for structural steel with similar strength and toughness.
China:
- Equivalent Grade: Q345B, Q345C, Q345D, Q345E
- Standard: GB/T 1591
- Notes: Chinese standard equivalent for high-strength low-alloy structural steel.
Japan:
- Equivalent Grade: SS490, SM490A, SM490B
- Standard: JIS G3101
- Notes: Japanese standard equivalent for general structural steel with good weldability.
Chemical Composition
Carbon (C):
Composition: 0.23-0.26%
Manganese (Mn):
Composition: 1.35-1.65%
Phosphorus (P):
Composition: 0.04% max
Sulfur (S):
Composition: 0.05% max
Silicon (Si):
Composition: 0.15-0.40%
Copper (Cu):
Composition: 0.20% min
Mechanical Properties
ASTM A572 Grade 50:
- Tensile Strength (ksi): 65 min (65-95 range)
- Yield Strength (ksi) (min): 50 min
- Elongation in 8″ (%) (min): 18%
- Elongation in 2″ (%) (min): 21%
- Charpy V-Notch Impact Test (ft-lbs): 20 min at -20°C (-4°F)
ASTM A572 Grade 65:
- Tensile Strength (ksi): 80 min (80-105 range)
- Yield Strength (ksi) (min): 65 min
- Elongation in 8″ (%) (min): 15%
- Elongation in 2″ (%) (min): 18%
- Charpy V-Notch Impact Test (ft-lbs): 15 min at -20°C (-4°F)
Fabrication and Welding
Fabrication:
Cutting
- Guidelines: Use mechanical cutting methods such as sawing, shearing, or flame cutting. Avoid excessive heat input to prevent degradation of material properties.
- Notes: Proper preheating may be required for thick sections to minimize internal stresses and distortion.
Forming
- Guidelines: Perform cold forming operations such as bending and rolling. Use a press brake or similar equipment to ensure uniform deformation and avoid excessive strain hardening.
- Notes: Avoid hot forming operations that can lead to reduced toughness and increased susceptibility to cracking.
Machining
- Guidelines: Use conventional machining techniques such as milling, drilling, and turning. Employ sharp tools and adequate coolant to minimize work hardening and tool wear.
- Notes: Preheat workpiece if necessary to reduce machining forces and extend tool life.
Welding:
Welding Processes
- Guidelines: Suitable processes include shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and flux-cored arc welding (FCAW).
- Notes: Choose welding process based on material thickness, joint configuration, and desired mechanical properties.
Preheating
- Guidelines: Preheat base metal and maintain interpass temperature within specified range to reduce the risk of hydrogen-induced cracking. Consult welding procedure specifications (WPS) for recommended preheat temperatures.
- Notes: Preheat temperature and interpass temperature depend on material thickness, carbon equivalent, and welding parameters.
Welding Consumables
- Guidelines: Select welding consumables with matching or slightly higher tensile and yield strengths than base metal. Use low-hydrogen electrodes or wires to minimize hydrogen content in the weld deposit.
- Notes: Ensure proper storage and handling of consumables to prevent moisture absorption and degradation of performance.
Post-Weld Heat Treatment (PWHT)
- Guidelines: Perform PWHT if required to relieve residual stresses and improve toughness. Follow specific PWHT procedures specified in applicable welding codes or standards.
- Notes: PWHT may be necessary for thick sections or when welding highly restrained joints to prevent cracking.
ASTM A572 Grade 50 Equivalent
ASTM A572 Grade 50 steel equivalent grades are often sought after by people to understand their compatibility and availability in other standards or countries. Some specific information on equivalent grades of ASTM A572 Grade 50 steel includes:
EN 10025 S355JR: This is a European standard equivalent to ASTM A572 Grade 50 steel. EN 10025 S355JR steel has similar mechanical properties and chemical composition, making it a common alternative in European markets.
GB/T 1591 Q345B: This is a Chinese standard equivalent to ASTM A572 Grade 50 steel. GB/T 1591 Q345B steel is widely used in China and has similar strength and mechanical properties to ASTM A572 Grade 50 steel.
JIS G3101 SS490: This is a Japanese standard equivalent to ASTM A572 Grade 50 steel. JIS G3101 SS490 steel is commonly used in Japan and has comparable strength and toughness characteristics to ASTM A572 Grade 50 steel.
ASTM A992: While not a direct equivalent, ASTM A992 is a commonly used high-strength, low-alloy structural steel with similar mechanical properties to ASTM A572 Grade 50 steel. It is often used in structural applications where higher strength is required.
