When selecting steel materials for industrial applications, understanding the difference between P355GH steel and S355J2 steel plates is essential. Although both grades offer similar strength levels, they are designed for completely different purposes.
P355GH steel
As a professional steel supplier, we recommend choosing the right material based on working temperature, pressure conditions, and application requirements-especially when safety and durability are critical.
What is P355GH Steel?
P355GH steel is a pressure vessel steel grade under the EN 10028-2 standard, specifically designed for elevated temperature service. The "P" represents pressure purposes, and "355" indicates a minimum yield strength of 355 MPa.
This grade is widely used in boilers, pressure vessels, heat exchangers, and pipelines transporting hot liquids. It offers excellent weldability and stable performance under high temperature conditions, typically up to 400°C. P355GH steel is usually supplied in the normalized condition, ensuring consistent mechanical properties and structural reliability.
What is S355J2 Steel?
S355J2 steel is a structural steel grade under EN 10025-2, mainly used for construction and engineering structures. The "S" stands for structural steel, while "J2" indicates that the material guarantees an impact energy of 27J at -20°C.
This grade is commonly used in bridges, buildings, machinery, and general structural components. Unlike P355GH, S355J2 is not specifically designed for high-temperature or pressure applications.
Chemical Composition Comparison of P355GH and S355J2
The chemical composition of both materials reflects their different applications.
P355GH Chemical Composition (%)
| Element | Content |
|---|---|
| C | 0.10 – 0.22 |
| Si | ≤ 0.60 |
| Mn | 1.10 – 1.70 |
| P | ≤ 0.025 |
| S | ≤ 0.015 |
| Al | ≥ 0.020 |
| N | ≤ 0.012 |
S355J2 Chemical Composition (%)
| Element | Content |
|---|---|
| C | ≤ 0.24 |
| Si | ≤ 0.60 |
| Mn | ≤ 1.70 |
| P | ≤ 0.035 |
| S | ≤ 0.035 |
Compared with S355J2, P355GH steel has stricter control on impurities such as phosphorus and sulfur, which improves its weldability and performance in high-temperature environments.
Mechanical Properties Comparison of P355GH and S355J2
Although both grades have similar yield strength levels, their performance characteristics differ significantly.
P355GH Mechanical Properties
| Thickness (mm) | Yield Strength (MPa) | Tensile Strength (MPa) |
|---|---|---|
| ≤16 | ≥355 | 510–650 |
| 16–40 | ≥345 | 510–650 |
| 40–100 | ≥315 | 490–630 |
| 100–250 | ≥280 | 470–630 |
S355J2 Mechanical Properties
| Thickness (mm) | Yield Strength (MPa) | Impact Energy |
|---|---|---|
| ≤16 | ≥355 | 27J @ -20°C |
| 16–40 | ≥345 | 27J @ -20°C |
| 40–100 | ≥315 | 27J @ -20°C |
S355J2 focuses more on low-temperature impact resistance, while P355GH emphasizes performance under pressure and elevated temperatures.
Key Differences Between P355GH and S355J2
The main differences between these two steel grades can be summarized as follows:
Application Purpose
P355GH is designed for pressure vessels and high-temperature service, while S355J2 is used for structural applications.
Temperature Performance
P355GH performs reliably at elevated temperatures, whereas S355J2 is optimized for low-temperature toughness.
Standard
P355GH follows EN 10028-2, while S355J2 follows EN 10025-2.
Material Focus
P355GH prioritizes pressure resistance and creep strength, while S355J2 focuses on structural strength and impact resistance.
Applications of P355GH Steel
For projects involving heat and pressure, P355GH steel plate is the preferred option. It is widely used in:
- Boilers and pressure vessels
- Heat exchangers
- Petrochemical equipment
- Pipelines transporting hot liquids
- Power plant systems
Its ability to maintain mechanical stability under long-term high-temperature exposure makes it more reliable than general structural steel.
While both materials have similar strength grades, their application fields are fundamentally different. P355GH steel is specifically engineered for pressure equipment operating under high temperatures, offering superior safety, weldability, and long-term performance.
If your project involves pressure vessels, boilers, or high-temperature pipelines, P355GH is undoubtedly the better choice compared to S355J2.
As a professional P355GH steel plate supplier, we offer a wide range of sizes (thickness 1–200mm, width up to 3500mm), third-party inspection support (SGS, BV, LR, etc.), and customized processing services. Contact us today for a competitive quote and expert technical support.
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What is P355GH material?
Steel for heat-resistant pressure vessels. P355GH steel gives optimum performance for pressurised products that must support a creep limit greater than 180N/mm2 at 400ºC. These types of steel are characterised by good weldability.
What is P355GH material equivalent to?
Notes: The BS EN 10028-2 P355GH steel plate is closely equivalent to ASTM A516 GR 70 and ASME SA 516 GR 70, particularly for pressure vessel applications, with P355GH offering slightly higher yield strength and stricter sulfur control for HIC resistance.
What is the difference between P355GH and P355NH?
P355GH steel is used worldwide by fabricators of welded pressure vessels, industrial boilers and heat exchangers and is engineered to work well in elevated temperature service. P355NH steel is normalized weldable fine grain steel flats under EN 10028-3: 2009 standard.
What is the yield strength of P355GH?
Carbon steels that are characterised by a greater resistance to pressure, capable of bearing significant pressure both at high and low temperatures. The yield strength ranges between 315 and 355 MPa, according to the range of thicknesses and its tensile strength goes from 510 to 650 MPa.
What is P355GH equivalent to ASTM material?
P355GH pressure vessel steel is an equivalent to ASTM A516 Grade 70 and ASME SA516 Grade 70.