Gangsteel, a leading manufacturer and exporter of pressure vessel and boiler steel plates, supplies high-quality ASTM A516 GR 70 and ASME SA516 GR 70 plates for industries such as oil and gas, petrochemical, and power generation. Engineers and fabricators often encounter questions about the differences between ASTM A516 GR 70 and ASME SA516 GR 70 plates. This article clarifies their chemical composition, mechanical properties, standards, and applications to guide material selection for pressure vessel projects.

Overview of Standards

The primary difference between ASTM A516 GR 70 and ASME SA516 GR 70 lies in their governing standards:

• ASTM A516 GR 70: Defined by the American Society for Testing and Materials (ASTM), this specification covers carbon steel plates for pressure vessels operating at moderate and low temperatures. It focuses on material properties and testing requirements.
• ASME SA516 GR 70: Established by the American Society of Mechanical Engineers (ASME), this specification is nearly identical to ASTM A516 GR 70 but is tailored for boiler and pressure vessel applications under ASME Boiler and Pressure Vessel Code (BPVC). It includes additional requirements for certification and traceability.

In practice, ASTM A516 GR 70 and ASME SA516 GR 70 plates are often identical in composition and properties, as most manufacturers, including Gangsteel, produce plates that meet both standards.

Chemical Composition

Both ASTM A516 GR 70 and ASME SA516 GR 70 share the same chemical composition, optimized for weldability and toughness in pressure vessel applications. The table below outlines the composition per ASTM/ASME standards:

Key Notes:

• Carbon: Capped at 0.27% to ensure weldability and prevent excessive hardness.
• Manganese: Enhances strength and toughness for high-pressure environments.
• Phosphorus and Sulfur: Low levels improve notch toughness, critical for low-temperature service.
• Aluminum: Ensures the steel is fully killed, reducing gas inclusions and enhancing uniformity.

Gangsteel’s plates meet both ASTM A516 GR 70 and ASME SA516 GR 70 requirements, with rigorous chemical testing to ensure compliance.

Mechanical Properties

The mechanical properties of ASTM A516 GR 70 and ASME SA516 GR 70 are identical, as both standards specify the same requirements for pressure vessel plates. The table below summarizes these properties:

Key Highlights:

• Tensile Strength: The 485–620 MPa range ensures durability in high-pressure vessels.
• Yield Strength: A minimum of 260 MPa supports structural integrity.
• Elongation: 17–21% ductility facilitates fabrication without cracking.
• Impact Toughness: Excellent low-temperature performance (-46°C) suits cryogenic applications.

Compared to other grades like ASTM A516 GR 65 or ASTM A516 GR 60, ASTM A516 GR 70 offers higher strength for more demanding applications.

Key Differences

While ASTM A516 GR 70 and ASME SA516 GR 70 are essentially the same material, the differences lie in their standards and applications:

• Standard Authority:
  • ASTM A516 GR 70 is governed by ASTM, focusing on material specifications for general pressure vessel use.
  • ASME SA516 GR 70 is governed by ASME, aligning with the BPVC for boiler and pressure vessel certification.
• Certification and Traceability:
  • ASME SA516 GR 70 requires additional documentation, such as Material Test Reports (MTRs), to comply with ASME BPVC requirements for coded vessels.
  • ASTM A516 GR 70 may not require the same level of certification unless specified.
• Applications:
  • Both are used for pressure vessels and boilers, but ASME SA516 GR 70 is mandatory for ASME-coded projects, ensuring compliance with regulatory standards.
  • ASTM A516 GR 70 is suitable for non-coded vessels or where ASME certification is not required.

Gangsteel’s plates are dual-certified to meet both ASTM A516 GR 70 and ASME SA516 GR 70 standards, offering flexibility for various project needs.

Applications

Both ASTM A516 GR 70 and ASME SA516 GR 70 are used in:

• Pressure Vessels: For oil, gas, and chemical processing, where high strength and low-temperature toughness are critical.
• Boilers: In power generation, providing thermal stability and durability.
• Cryogenic Equipment: Suitable for LNG storage due to excellent impact toughness.
• Fabrication: Their weldability supports complex assemblies in industrial equipment.

ASME SA516 GR 70 is specifically required for ASME-coded vessels, while ASTM A516 GR 70 is suitable for general pressure vessel applications.

Weldability

Both grades are fully killed carbon steels with excellent weldability using SMAW, GTAW, and SAW processes. The low carbon content minimizes weld imperfections, and normalization enhances toughness. Gangsteel supplies plates in normalized or hot-rolled conditions to meet fabrication requirements.

Comparison with Other Grades

For context, compare ASTM A516 GR 70 with other A516 grades:

For global equivalents, refer to Gangsteel’s ASME SA516 GR 70 Equivalent Grade guide.

Gangsteel Solution

Gangsteel is a global leader in supplying ASTM A516 GR 70 and ASME SA516 GR 70 plates, offering:

• Certified Quality: Dual-certified plates undergo ultrasonic testing, Charpy impact tests, and chemical analysis to meet ASTM/ASME standards.
• Customization: Available in normalized or hot-rolled forms for specific project needs.
• Global Supply: Competitive pricing and reliable delivery worldwide.
• Technical Support: Guidance on selecting ASTM A516 GR 70 versus ASTM A516 GR 65, ASTM A516 GR 60, or ASTM A516 GR 55.

ASTM A516 GR 70 and ASME SA516 GR 70 are essentially identical in composition and properties, with SA516 GR 70 offering additional ASME certification for coded vessels. Gangsteel’s plates ensure reliability for all pressure vessel applications. For equivalent standards, explore our ASME SA516 GR 70 Equivalent Grade guide.