ASTM A662
Basic Info
The ASTM A662 standard specifies the standard specifications for carbon steel plates for low and medium temperature pressure vessels. These steel plates have good weldability and toughness, making them suitable for manufacturing equipment such as storage tanks and boilers.
Characteristics
Moderate Strength: ASTM A662 steel exhibits moderate strength suitable for pressure vessel applications, providing adequate structural integrity under operating conditions.
Excellent Notch Toughness: ASTM A662 steel demonstrates excellent notch toughness, meaning it can withstand the presence of stress concentrations without fracturing, making it reliable for use in pressure vessels subjected to varying loads.
Notch Sensitivity: Despite its excellent notch toughness, ASTM A662 steel may exhibit sensitivity to notch effects, requiring careful consideration of design and fabrication processes to avoid premature failure.
Normalized Condition: ASTM A662 steel plates are typically supplied in normalized condition, which improves its mechanical properties, including hardness and tensile strength, enhancing its suitability for pressure vessel applications.
Moderate Temperature Service: ASTM A662 steel is designed for use in moderate and lower temperature service, making it suitable for a wide range of industrial applications, including boilers and pressure vessels operating under various temperature conditions.
ASTM A662 Data Sheet
Characteristics
Steel Grade
Dimensions and Tolerances
Equivalent Steel Grades
Chemical Composition
Mechanical Properties
Fabrication and Welding
Characteristics
Grade A
- Description: ASTM A662 Grade A steel is a carbon-manganese-silicon steel plate primarily used in pressure vessel applications. It offers moderate strength and notch toughness, suitable for moderate and lower temperature service.
Grade B
- Description: ASTM A662 Grade B steel is a carbon-manganese-silicon steel plate designed for use in pressure vessel applications requiring higher strength than Grade A. It exhibits good weldability and notch toughness, making it suitable for various industrial applications.
Grade C
- Description: ASTM A662 Grade C steel is a carbon-manganese-silicon steel plate with the highest strength among the three grades. It is specifically designed for pressure vessel applications requiring superior strength and notch toughness at moderate and lower temperatures.
Steel Grade
Shape: Plate/Sheet
- Width (mm): 600–2500
- Thickness (mm): 6–150
- Tolerance on Width (mm): ± 10
- Tolerance on Thickness (mm): ± 0.5
Shape: Coil/Strip
- Width (mm): 600–2500
- Thickness (mm): 0.6–6.0
- Tolerance on Width (mm): ± 10
- Tolerance on Thickness (mm): ± 0.05 (for thickness ≤ 0.25)
Dimensions and Tolerances
Plate/Sheet
- Width (mm): 600-2500
- Thickness (mm): 6-150
- Tolerance on Width (mm): ± 10
- Tolerance on Thickness (mm): ± 0.5
Coil/Strip
- Width (mm): 600-2500
- Thickness (mm): 0.6-6.0
- Tolerance on Width (mm): ± 10
- Tolerance on Thickness (mm): ± 0.05 (for thickness ≤ 0.75)
Equivalent Steel Grades
United States:
- Equivalent Grade: SA662 Grade A/B/C
- Standard: ASME SA662
- Notes: Equivalent to ASTM A662 Grade A/B/C
Germany:
- Equivalent Grade: HI/II/III
- Standard: DIN 17155
- Notes: DIN standard for pressure vessel steels
Japan:
- Equivalent Grade: SB410/450/480
- Standard: JIS G3103
- Notes: JIS standard for carbon steel and molybdenum alloy steel plates for boilers and pressure vessels
China:
- Equivalent Grade: 16MnR/20R/16MnDR
- Standard: GB 713
- Notes: Chinese standard for boiler and pressure vessel steel
Chemical Composition
Carbon (C): Maximum 0.22%
Manganese (Mn): 0.79% – 1.62%
Phosphorus (P): Maximum 0.035%
Sulfur (S): Maximum 0.035%
Silicon (Si): 0.13% – 0.55%
Nickel (Ni): Maximum 0.60%
Chromium (Cr): Maximum 0.60%
Molybdenum (Mo): Maximum 0.41%
Copper (Cu): Maximum 0.35%
Vanadium (V): Maximum 0.03%
Mechanical Properties
Tensile Strength (Room Temperature):
- Grade A: 515–690 MPa
- Grade B: 550–760 MPa
- Grade C: 620–795 MPa
Yield Strength (Room Temperature):
- Grade A: ≥ 310 MPa
- Grade B: ≥ 334 MPa
- Grade C: ≥ 345 MPa
Elongation (50 mm gauge length):
- Grade A: ≥ 20%
- Grade B: ≥ 20%
- Grade C: ≥ 20%
Reduction of Area:
- Grade A: ≥ 35%
- Grade B: ≥ 35%
- Grade C: ≥ 35%
Charpy V-notch Impact Energy (Room Temperature):
- Grade A: ≥ 20 J min at -20°C
- Grade B: ≥ 20 J min at -20°C
- Grade C: ≥ 20 J min at -20°C
Fabrication and Welding
Preheating:
- Guidelines: Preheating is generally not required for ASTM A662 steel unless specified by the applicable code or standard for specific applications.
Welding Processes:
- Guidelines: Common welding processes such as SMAW (Shielded Metal Arc Welding), GTAW (Gas Tungsten Arc Welding), and GMAW (Gas Metal Arc Welding) can be used.
Welding Electrodes:
- Guidelines: Low hydrogen electrodes with a tensile strength matching or exceeding that of the base metal are recommended for welding ASTM A662 steel.
Welding Consumables:
- Guidelines: Use filler materials with appropriate mechanical properties and chemical composition to match the base metal or as specified by the welding procedure.
Post-Weld Heat Treatment:
- Guidelines: Post-weld heat treatment may be required for specific applications to relieve residual stresses and improve mechanical properties.
PWHT Temperature & Duration:
- Guidelines: If post-weld heat treatment is necessary, follow the recommended temperature and duration specified in the applicable code or standard.
Welding Precautions:
- Guidelines: Take precautions to avoid excessive heat input, which can lead to distortion or degradation of mechanical properties. Ensure proper joint preparation and fit-up for sound welds. Maintain cleanliness of the welding environment to prevent contamination.
Quality Assurance and Standards Compliance of ASTM A662
Adherence to ASTM Standards: ASTM A662 steel is produced in accordance with the standards set forth by the American Society for Testing and Materials (ASTM). This ensures that the material meets specific requirements for chemical composition, mechanical properties, fabrication, and testing, as outlined in the ASTM A662/A662M standard.
Quality Control in Manufacturing: Manufacturers of ASTM A662 steel employ rigorous quality control measures throughout the production process. This includes sourcing of raw materials, alloying, casting or forming, heat treatment, and finishing operations. By adhering to strict quality control protocols, manufacturers can maintain consistency and reliability in the properties of ASTM A662 steel products.
Certification and Traceability: ASTM A662 steel products are often accompanied by certification documents attesting to their compliance with the ASTM standard and other relevant specifications. These documents provide essential information about the material’s chemical composition, mechanical properties, heat treatment, and testing results. Additionally, traceability measures ensure that each batch or lot of ASTM A662 steel can be tracked back to its source, facilitating accountability and quality assurance throughout the supply chain.
