ASTM A516 Gr 60 vs Gr 70

ASTM A516 Gr 60 vs. Gr 70: A Detailed Comparison for Pressure Vessel Applications

What is the difference between A516 Gr 60 and Gr 70

When selecting materials for pressure vessels, ASTM A516 Gr 60 and ASTM A516 Gr 70 are two widely used carbon steel plates known for their suitability in moderate and lower-temperature services.

At Gangsteel, we specialize in supplying both A516 Gr 60 plate and A516 Gr 70 plate with NACE and HIC compliance for demanding applications. This article provides a detailed comparison of these two grades, focusing on their chemical composition, mechanical properties, applications, and suitability for pressure vessel steel plate for sour gas environments. By understanding their differences, you can make an informed choice for your project needs.

1. ASTM A516 Gr 60 and Gr 70

Both ASTM A516 Gr 60 and ASTM A516 Gr 70 are carbon steel plates specified under the ASTM A516 standard for pressure vessels operating in moderate and low-temperature conditions. These grades are often enhanced with NACE MR0175/ISO 15156 compliance and HIC (Hydrogen Induced Cracking) testing, making them ideal for boiler quality steel plate for oil and gas applications. While they share similarities, their differences in chemical composition and mechanical properties make them suitable for distinct use cases.

• A516 Gr 60: A lower-strength grade with good weldability and toughness, often used in less demanding pressure vessel applications.
• A516 Gr 70: A higher-strength grade with enhanced tensile and yield properties, preferred for more robust pressure vessel requirements.

2. Chemical Composition Comparison

The chemical composition of ASTM A516 Gr 60 and Gr 70 is similar but varies slightly in carbon content, which impacts their strength and performance in pressure vessel steel plate for petrochemical applications.

ASTM A516 Gr 60 Chemical Composition

• Carbon (C):
  • ≤ 0.21% (thickness <12.5mm)
  • ≤ 0.23% (12.5-50mm)
  • ≤ 0.25% (50-100mm)
  • ≤ 0.27% (100-200mm)
  • ≤ 0.27% (>200mm)
• Silicon (Si): 0.15-0.40%
• Manganese (Mn): 0.60-1.20%
• Phosphorus (P): ≤ 0.035%
• Sulfur (S): ≤ 0.035%

ASTM A516 Gr 70 Chemical Composition

• Carbon (C):
  • ≤ 0.27% (thickness <12.5mm)
  • ≤ 0.28% (12.5-50mm)
  • ≤ 0.30% (50-100mm)
  • ≤ 0.31% (100-200mm)
  • ≤ 0.31% (>200mm)
• Silicon (Si): 0.15-0.40%
• Manganese (Mn): 0.85-1.20%
• Phosphorus (P): ≤ 0.035%
• Sulfur (S): ≤ 0.035%

Key Difference:

• A516 Gr 70 has a slightly higher carbon and manganese content, which contributes to its increased strength compared to A516 Gr 60 plate. The higher carbon content in Gr 70 may slightly reduce weldability but enhances its tensile properties, making it suitable for ASTM A516 Gr 70 NACE HIC steel plate for oil and gas applications.

Carbon Equivalent (Ceq): Both grades use the formula Ceq = [C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15] %. Due to the higher carbon and manganese in Gr 70, its Ceq is slightly higher, which may require additional welding precautions.

3. Mechanical Properties Comparison

The mechanical properties of ASTM A516 Gr 60 and Gr 70 are a key factor in determining their suitability for specific applications.

ASTM A516 Gr 60 Mechanical Properties

• Yield Strength: ≥ 220 MPa
• Tensile Strength: 415-550 MPa
• Elongation:
  • ≥ 23% (6-40mm thickness)
  • ≥ 21% (40-100mm thickness)

ASTM A516 Gr 70 Mechanical Properties

• Yield Strength: ≥ 260 MPa
• Tensile Strength: 485-620 MPa
• Elongation:
  • ≥ 21% (6-40mm thickness)
  • ≥ 17% (40-100mm thickness)

Key Difference:

• A516 Gr 70 offers higher yield and tensile strength, making it more suitable for applications requiring greater structural integrity under higher pressure, such as boiler quality steel plate for petrochemical applications.
• A516 Gr 60 has slightly better elongation, indicating improved ductility and ease of forming, which is advantageous for pressure vessel steel plate for sour gas environments where complex shapes are needed.

4. Weldability and Fabrication

Both grades are known for excellent weldability due to their low carbon content, but A516 Gr 60 has a slight edge due to its lower carbon and manganese levels, which reduce the risk of weld imperfections. This makes A516 Gr 60 plate ideal for applications requiring extensive welding and fabrication.

A516 Gr 70, with its higher carbon equivalent, may require preheating or post-weld heat treatment in thicker sections to prevent cracking, particularly in ASTM A516 Gr 70 NACE HIC steel plate for petrochemical applications. However, both grades are compatible with standard welding techniques, ensuring versatility in fabrication.

5. Applications

The choice between A516 Gr 60 and Gr 70 depends on the specific demands of the project.

Applications of ASTM A516 Gr 60

• Oil and Gas: Used in pipelines, storage tanks, and pressure vessels in less demanding sour gas environments.
• Petrochemical Industry: Suitable for reactors and heat exchangers where moderate strength is sufficient.
• Power Generation: Ideal for boilers and steam drums operating at lower pressures.
• Chemical Processing: Used in equipment handling less aggressive chemicals, leveraging its ductility for pressure vessel steel plate for oil refineries.

Applications of ASTM A516 Gr 70

• Oil and Gas: Preferred for high-pressure pipelines and vessels in sour gas environments, ideal for boiler quality steel plate for oil and gas.
• Petrochemical Industry: Used in high-pressure reactors and columns requiring enhanced strength.
• Power Generation: Suitable for boilers and pressure vessels operating under higher pressure and temperature.
• Offshore Platforms: Employed in structures exposed to harsh marine conditions, benefiting from its robustness in ASTM A516 Gr 70 NACE HIC steel plate for oil and gas applications.

Key Difference: A516 Gr 70 is better suited for high-pressure and high-strength applications, while A516 Gr 60 is preferred for projects prioritizing weldability and formability in less demanding conditions.

6. Equivalent Grades

Both grades align with international standards, ensuring compatibility for global projects.

ASTM A516 Gr 60 Equivalent Grades

• Germany: E St E315
• Italy: Fe 460-2-KG
• Sweden: SS29,12,01

ASTM A516 Gr 70 Equivalent Grades

• Europe: P355GH
• Germany: E St E355
• Italy: Fe 510-2-KG
• Sweden: SS29,13,01

Key Difference: The equivalent grades for A516 Gr 70 reflect its higher strength, aligning with standards like P355GH, which are designed for more robust applications compared to A516 Gr 60 plate.

7. NACE and HIC Compliance

Both ASTM A516 Gr 60 and Gr 70 can be supplied with NACE MR0175/ISO 15156 and HIC compliance, making them suitable for pressure vessel steel plate for sour gas environments. Gangsteel ensures rigorous testing, including:

• HIC Testing: Verifies resistance to Hydrogen Induced Cracking in H2S-rich environments.
• NACE Compliance: Ensures suitability for corrosive conditions.
• Supplementary Tests: Includes Z15, Z25, Z35, S1, S2, S3, S4.1, S5, S6, S7, S8, S9, S11, S12, S14, and S17, as per ASTM A516 standards.

Key Difference: While both grades are HIC-resistant, A516 Gr 70 is often preferred in more severe sour gas environments due to its higher strength, as seen in ASTM A516 Gr 70 NACE HIC steel plate for petrochemical applications.

8. Dimensions and Availability

Both grades are available in:

• Thickness: 6mm to 300mm
• Width: 1500mm to 4050mm
• Length: 3000mm to 15000mm

Gangsteel offers customized sizes for both A516 Gr 60 plate and A516 Gr 70 plate, ensuring flexibility for boiler quality steel plate for oil and gas.

9. Why Choose Gangsteel for ASTM A516 Gr 60 and Gr 70?

As a leading ASTM A516 Gr 60 and Gr 70 NACE HIC steel plate supplier, Gangsteel offers:

• Quality Assurance: Rigorous testing for HIC, NACE, and ASTM compliance.
• Global Export: Efficient logistics for worldwide delivery.
• Customization: Tailored sizes and specifications for specific project needs.
• Competitive Pricing: Cost-effective solutions for pressure vessel steel plate for petrochemical applications.
• Expert Support: Technical guidance to choose between A516 Gr 60 plate and A516 Gr 70 plate.

10. Conclusion

The choice between ASTM A516 Gr 60 and Gr 70 depends on your project’s requirements:

• Choose A516 Gr 60 for applications prioritizing weldability, ductility, and moderate strength, ideal for pressure vessel steel plate for oil refineries with less demanding conditions.
• Choose A516 Gr 70 for high-pressure, high-strength applications in severe environments, such as ASTM A516 Gr 70 NACE HIC steel plate for oil and gas applications.

Gangsteel is your trusted partner for both grades, delivering high-quality boiler quality steel plate for sour gas environments. For more details or to request a quote, visit our A516 Gr 60 product page or A516 Gr 70 product page, or contact our team for personalized support.