In pressure vessel and boiler fabrication, ASME SA516 Grade 70 and ASME SA612 are two widely used carbon steel plates. While both belong to the ASME Boiler and Pressure Vessel Code (BPVC) material system, they are designed with different performance priorities. Understanding their differences helps engineers and procurement teams select the most cost-effective and technically appropriate material.
| Item | SA516 Gr.70 | SA612 |
|---|---|---|
| Standard | ASTM A516 / ASME SA516 | ASTM A612 / ASME SA612 |
| Design Focus | Good toughness at moderate & lower temperatures | Higher strength for reduced thickness |
| Typical Service | Boilers, pressure vessels | Medium & low-temperature welded pressure vessels |
SA516 Gr.70 is optimized for notch toughness and general pressure vessel service, while SA612 is designed as a high-strength pressure vessel quality (PVQ) steel, allowing thinner plates at the same design pressure.
Chemical Composition (Typical Comparison)
| Element | SA516 Gr.70 | SA612 |
|---|---|---|
| Carbon (C) | ≤ 0.27% | ≤ 0.25% |
| Manganese (Mn) | 0.85–1.20% | 1.00–1.50% |
| Silicon (Si) | 0.13–0.45% | 0.15–0.50% |
| P / S | Low | Low |
Mechanical Properties
| Property | SA516 Gr.70 | SA612 |
|---|---|---|
| Yield Strength | ≥ 260 MPa | ≥ 345 MPa |
| Tensile Strength | 485–620 MPa | 560–725 MPa |
| Elongation | Higher | Slightly lower but adequate |
Application Scenarios
SA516 Gr.70 Applications
High-pressure boilers and steam generators
Industrial pressure vessels (chemical, petrochemical, pharmaceutical industries)
Oil and gas storage tanks and pipelines
Power plant equipment (nuclear, thermal power)
SA612 Applications
Low-temperature pressure vessels (LNG carriers, cryogenic storage tanks)
Refrigeration and air conditioning equipment
Offshore platforms in cold climates (Arctic, North Sea)
Low-temperature pipelines and valves
Weldability and Fabrication
| Aspect | SA516 Gr.70 | SA612 |
|---|---|---|
| Weldability | Excellent | Very good |
| Preheating | Usually not required | Sometimes recommended for thick plates |
| Fabrication | Easy forming | Slightly higher forming force |
SA516 Gr.70 remains the most fabrication-friendly choice, while SA612 still maintains good weldability with proper welding procedure control.
Low-Temperature Performance
SA516 Gr.70
Widely accepted for applications requiring impact testing
Better notch toughness in normalized condition
SA612
Suitable for medium and low temperatures
Focuses more on strength than extreme low-temperature toughness
For very low-temperature or impact-critical service, SA516 Gr.70 may be preferred unless SA612 is specifically tested.
GNEE's Supply Capabilities for SA516 Gr.70 and SA612
As a professional ASME-certified steel supplier, GNEE offers:
- Full compliance with ASME SA-516/SA-612 standards, with mill test certificates (MTC) including chemical composition, mechanical properties, and impact test results.
- Customizable thicknesses (6mm-300mm for SA516 Gr.70; 6mm-150mm for SA612) and cutting services (plasma, flame cutting).
- Quality control: Non-destructive testing (NDT) options (UT, RT, MT, PT) to ensure zero defects.
- Global delivery: Fast shipping to North America, Europe, Southeast Asia, and other regions.
For project-specific material recommendations or quotes, contact GNEE's technical team for personalized support.
Both SA516 Gr.70 and SA612 are reliable ASME pressure vessel steels, but they serve different engineering goals.
- Choose SA516 Gr.70 for balanced toughness, ease of fabrication, and wide code acceptance.
- Choose SA612 when higher strength, reduced thickness, and lower total project cost are the priorities.
As a professional pressure vessel steel supplier, GNEE STEEL provides both grades with full MTC certification, customized dimensions, and technical support to help customers select the optimal material for their projects.
Email: ru@gneesteelgroup.com
Whatsapp (WeChat): +86 15824687445
FAQ
What is SA 612 material?
carbon-manganese-silicon steel plate
SA612 is killed carbon-manganese-silicon steel plate made for welded pressure vessels. Its fine grain makes it suitable for use in moderate and lower temperature service where impact resistance is important.
What is the composition of ASTM A612?
ASTM A612 steel plate is a high-strength low-alloy (HSLA) steel plate designed for welded pressure vessels. It has a nominal composition of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, and copper.
What is A612 steel?
ASTM A612 specification is the Standard Specification for Pressure Vessel Plates, Carbon Steel, High Strength, for Moderate and Lower Temperature Service. ASTM A612 encompasses carbon-manganese-silicon steel plates intended for use in welded pressure vessels for moderate and low temperature service.
Are SA612 and A612 Steel Plates the Same Product? What Are the Core Differences?
They are the same type of steel plate. ASTM A612 is the material standard, while ASME SA612 is the designation assigned after ASTM A612 was incorporated into the ASME Boiler & Pressure Vessel Code, specifically for the fabrication of pressure-bearing equipment.
What Are the Executive Standards for SA612/A612 Steel Plates? Are There Any Differences Between the ASTM and ASME Versions?
The executive standards are ASTM A612/A612M and ASME SA612. There are no substantial differences in chemical composition and mechanical properties between the two versions; the only variance lies in their applicable code systems.
What Are the Equivalent Grades of SA612/A612 in Chinese and European Standards? Can They Be Used as Direct Substitutes?
Common approximate equivalent grades include EN P355GH, DIN 1.0473, and GB Q345R. However, they cannot be used as direct equivalents. Their suitability must be confirmed in accordance with design specifications and approval requirements.
What Are the Yield Strength and Tensile Strength of SA612/A612? Do They Vary with Different Thicknesses?
The minimum yield strength of SA612 is approximately 260 MPa, and its tensile strength ranges from 485–620 MPa. As the thickness increases, the allowable minimum yield strength may decrease slightly.
What Are the Low-Temperature Impact Energy Requirements for SA612/A612? Are the Requirements at -40℃ and -45℃ Consistent?
Standards typically require impact testing at -40℃, while testing at -45℃ is not mandatory. If a project specifies -45℃ testing, additional impact tests must be conducted and clearly defined in the technical agreement.
What Are the Minimum and Maximum Service Temperatures for SA612/A612?
The recommended minimum service temperature is approximately -40℃, and the maximum operating temperature is generally around 400℃, depending on the design specifications and service medium.
What Is the Carbon Equivalent of ASME SA612? Is Preheating Required for Welding?
The carbon equivalent is usually around 0.42–0.45. Preheating at 50–120℃ is recommended for welding medium and thick plates. Commonly used welding materials include low-hydrogen electrodes such as E7018 and E7016.
What Is the Routine Thickness Range of SA612/A612, and What Is the Maximum Customizable Thickness?
The routine thickness range is 6–100 mm. Some steel mills can provide customized thicknesses up to 150 mm, subject to confirmation of their rolling and heat treatment capabilities.
What Are the Common Delivery Conditions for SA612/A612?
Common delivery conditions include As-Rolled (AR), Normalized (N), and Normalized + Tempered (N+T), with the normalized condition being the most widely used.
What Is the Machinability of SA612? Is It Prone to Cracking?
SA612 exhibits excellent cutting and bending performance. When processed with proper techniques and preheating, it is not prone to cracking.
Which Is More Suitable for Low-Temperature Applications: SA612 or SA516 Gr.70?
SA612 delivers more stable comprehensive performance in thick plate and high-stress working conditions, whereas SA516 Gr.70 offers better cost-effectiveness in conventional operating conditions.
Can Q345R Be Used as a Substitute for SA612?
Q345R can be used as a substitute in some working conditions for non-ASME projects. However, substitution is not recommended for export projects or scenarios where SA612 is explicitly required by specifications.
What Are the Differences Between SA612 and SA537 Cl.2?
SA537 Cl.2 boasts higher strength and low-temperature performance but comes with a significantly higher cost than SA612. It is suitable for more severe operating conditions.
Is SA612 Vessel Plate Suitable for LNG Storage Tanks?
SA612 is not recommended for primary LNG storage tanks operating at -162℃, but it can be used in LNG auxiliary systems or medium-to-low temperature vessels.
What Is the Hydrogen-Induced Cracking (HIC) Resistance of SA612 Steel Plates?
Standard SA612 does not mandate HIC resistance requirements. For applications involving sulfur-containing media, customized low-sulfur and low-phosphorus SA612 plates must be used, accompanied by HIC testing.
| Other steel plate by GNEE | ||||
| Name | Material | Specification (mm) | Tons | Remark |
| Clad steel plate | P265GH+410,S355JR+410,A516Gr70+316, A537CL1+304L,Q235B+304L,Q345B+304, A516Gr70(NACE)+410,A537CL1+904L, A537CL1+316L,A516Gr70+304L,A537CL1+304 ,A516Gr70+410,A516Gr70+904L |
2-300mm(Based plate),1-50mm(Composited plate) | / | UT, AR, TMCP.Normalized, Quenched and Tempered,Z Direction Test, Charpy V-Notch impact TestThe Third Party Test , Coated or Shot Blasting and Painting. |
| Low Alloy | Q345A, Q345B, Q345C, Q345D, Q345E, Q390, Q420, Q460C, ST52-3, S355J2+N, SS400, SA302GrC, S275NL, 35CrMo | 6 - 350 | 5788.56 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| Pressure Vessel Plate | A204 Grade B,A515 Grade 70,A537 Class 1,SA387 Grade 11 Class 1,P265GH,S537 Class 2,P355Q,P275N,P355N,P690Q,Q345R, | 3 - 300 | 8650 | Normalizing, tempered ,controlled rolling, hot rolling , Hot rolling,1st inspection, 2nd inspection, 3rd inspection |
| High-Strength Plate | A514 Grade F, A572 Grade 50, A588 Grade A, S355JR, S690Q, SS400, S690QL, Q345B, Q345E | 8 - 120 | 3086.352 | Quenched and tempered |
| Wear-Resistant Plate | NM360, NM400, NM450, NM500 | 6 - 150 | 3866.297 | Quenched and tempered |
| Ship Plate | ABS AH32,ABS DH32,ABS EH32,ABS FH36,ASTM A131 A, ASTM A131 EH32,ASTM A131 AH36,CCS A,CCS AH32,LR AH32, DNV A36,BV AH32 |
8 - 200 | 2853.621 | Hot rolling, normalized ,hot rolling controlled rolling, quenched and tempered + toughness and brittleness |