In the manufacturing of pressure vessels, boilers, heat exchangers and petrochemical equipment, material selection directly determines equipment safety, service life and manufacturing costs. Among various pressure vessel steel plates, ASTM A612 and EN 10028 P355GH are two widely adopted grades.
As they belong to the American standard system and European standard system respectively, many engineers, procurement specialists and equipment manufacturers encounter a common issue during project execution：
How to quickly determine which grade to select?
- If the project follows ASME codes, A612 shall be the preferred material;
- If the project complies with EN/PED directives, P355GH shall be prioritized;
- For equipment operating continuously under steam and high-temperature heat exchange conditions, P355GH offers superior performance;
- For ASME pressure vessels serving the oil and gas sector, A612 is generally the more suitable option.
Contact us now for the latest quote on ASTM A612.
What is ASTM A612 and P355GH steel plate?
ASTM A612 is a high-strength carbon-manganese-silicon steel plate designed for welded pressure vessels operating at moderate and lower temperatures. It is commonly used in North American projects and equipment built according to ASME pressure vessel codes. The material offers good strength, toughness, and fabrication performance.
This steel grade features:
- Excellent tensile strength performance.
- Good low-temperature toughness.
- Outstanding weldability.
- Favourable formability.
Especially for projects governed by the ASME standard system, A612 is a mature and widely utilized material for pressure vessels.
P355GH is a normalized pressure vessel steel specified under EN 10028. It is one of the most widely used pressure vessel steels in Europe and is commonly applied in boilers, heat exchangers, petrochemical equipment, and storage vessels. The grade is designed for elevated-temperature service while maintaining excellent weldability and toughness.
- P stands for Pressure
- 355 refers to the minimum yield strength of 355 MPa
- GH denotes suitability for high-temperature service
P355GH is generally supplied in the normalized delivery condition, featuring stable metallographic structure and reliable high-temperature mechanical properties.
ASTM A612 and P355GH Typical Application Fields
Common Applications of A612：
- Petroleum storage tanks.
- Natural gas separators.
- Pressure vessels.
- LNG storage facilities.
- Chemical reactors.
Common Applications of P355GH：
- Industrial boilers.
- Heat exchangers.
- Steam systems.
- Petrochemical equipment.
- Power plant pressure components.
Under what service conditions should ASTM A612 be selected?
ASME Pressure Vessel Projects
A612 (SA612) is a commonly used pressure vessel steel plate under the US ASTM/ASME standard system. For all equipment designed and fabricated in accordance with ASME Section VIII, A612 is generally the preferred material.
Project Requirements Suitable for A612
- ASME U Stamp certification.
- NB registration.
- Market access to North America.
- A612 is usually more readily accepted than P355GH for such projects.
A612 is usually more readily accepted than P355GH for such projects.
| Application Scenarios | Recommended Material |
|---|---|
| ASME Pressure Vessels | A612 |
| PED Pressure Equipment | P355GH |
| North American Projects | A612 |
| European Projects | P355GH |
| Oil & Gas Separators | A612 |
| Industrial Boilers | P355GH |
| Heat Exchangers | P355GH |
| LNG Storage Tanks | A612 |
| Steam Systems | P355GH |
| Equipment with Heavy Welding Workload | P355GH |
| Thick-Wall High-Strength Vessels | A612 |
| CE Certified Equipment | P355GH |
Under what service conditions should P355GH be selected?
1. PED-Certified Pressure Equipment
P355GH is the most widely used pressure vessel steel plate specified in the European standard EN 10028.
For all projects that require compliance with:
- PED 2014/68/EU
- CE marking certification
- EN design codes
- P355GH is generally the material of first choice.
2. Equipment Operating at High Temperatures Long-Term
The suffix "GH" in P355GH indicates its suitability for high-temperature pressure equipment.
Typical Service Conditions
- Steam piping
- Boiler drums
- Heat exchanger shells
- Hot oil systems
- Normal operating temperature range: 200°C ~ 400°C
P355GH maintains a stable metallographic structure and reliable high-temperature mechanical properties under prolonged thermal cycling.
3. Equipment with Strict Weldability Requirements
P355GH is normally supplied in the normalized condition.
Its key advantages:
- Low carbon content
- Low susceptibility to welding cracking
- Consistent post-weld mechanical properties
- Wide welding procedure qualification window
Suitable applications:
- Mass automated welding production
- Fabrication of thick-wall boilers
- Manufacturing of large heat exchangers
For equipment featuring complex weld joints and extensive welding work, P355GH enables far easier control over welding quality compared to A612.
4. Projects Destined for European Markets
If finished equipment is to be exported to European countries including: Germany, France, Italy, the Netherlands, Poland, etc.
P355GH is the most readily recognized material. European design institutes and inspection bodies accept P355GH far more readily than ASTM A612.
Performance Comparison: A612 vs P355GH
| Item | ASTM A612 | EN 10028 P355GH |
|---|---|---|
| Standard System | ASTM/ASME | EN 10028 |
| Primary Target Markets | North America, Middle East, Asia | Europe |
| Minimum Yield Strength | ≥345 MPa | ≥355 MPa |
| Tensile Strength | 550–725 MPa | 490–630 MPa |
| Delivery Condition | As-rolled or Normalized | Normalized |
| Weldability | Good | Excellent |
| Design Codes | ASME Section VIII | PED / EN Standards |
| Typical Applications | Pressure vessels, storage tanks | Boilers, pressure vessels |
Judging from the data, both grades are medium-to-high strength steel plates for pressure vessels, yet there are distinct differences in their design code systems and applicable service environments.
Contact us now for the latest quote on ASTM A612.
Need Help Selecting the Right Pressure Vessel Steel?
We support ASTM SA612, EN P355GH, and equivalent pressure vessel steels with full MTC, third-party inspection, and global delivery.
👉 Contact us now for technical comparison sheets, project-specific recommendations, or quotation support.
FAQ:
1.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.
2.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.
3.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.
4.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.
5.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.
