P355GH and P355NH steel plays a crucial role in determining their performance in pressure vessel applications. Both grades are widely used under European standards, but they are designed for different service conditions.
P355GH and P355NH steel
P355GH is specified under EN 10028-2 for elevated temperature applications, while P355NH follows EN 10028-3 and is designed for normalized fine-grain steels with improved toughness.
Understanding their composition differences helps engineers and buyers select the right material for specific projects.
What are P355GH and P355NH Steel?
According to EN 10020, both P355GH and P355NH steel are classified as non-alloy steels. However, they differ in their intended applications:
- P355GH (1.0473): Designed for pressure vessels at elevated temperatures
- P355NH (1.0565): Designed for pressure vessels requiring better toughness and fine-grain structure
Both materials can be supplied in normalized condition or produced using normalizing rolling processes, depending on manufacturing requirements.
Chemical Composition of P355GH Steel
The chemical composition of P355GH steel is optimized for high-temperature performance and weldability.
| 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 |
| Cr | ≤ 0.30 |
| Cu | ≤ 0.30 |
| Mo | ≤ 0.08 |
| Nb | ≤ 0.020 |
| Ni | ≤ 0.30 |
| Ti | ≤ 0.03 |
| V | ≤ 0.02 |
| Nb+Ti+V | ≤ 0.70 |
This composition ensures good weldability and stable performance at elevated temperatures.
Chemical Composition of P355NH Steel
The chemical composition of P355NH steel is more strictly controlled to achieve fine-grain structure and improved toughness.
| Element | Content (%) |
|---|---|
| C | ≤ 0.18 |
| Si | ≤ 0.50 |
| Mn | 1.10 – 1.70 |
| P | ≤ 0.025 |
| S | ≤ 0.015 |
| Al | ≥ 0.020 |
| N | ≤ 0.012 |
| Cr | ≤ 0.30 |
| Cu | ≤ 0.30 |
| Mo | ≤ 0.08 |
| Nb | ≤ 0.05 |
| Ni | ≤ 0.05 |
| Ti | ≤ 0.03 |
| V | ≤ 0.10 |
| Nb+Ti+V | ≤ 0.12 |
Chemical Composition of P355GH and P355NH steel
The differences between P355GH and P355NH steel composition reflect their application focus:
Carbon Content
P355NH has lower carbon (≤0.18), improving weldability and toughness
Micro-alloying Elements
P355NH allows higher Nb and V for grain refinement
Combined Alloy Limits
P355NH has stricter control over alloy combinations for better structural performance
Overall, P355NH is optimized for toughness, while P355GH is optimized for high-temperature service.
Impact of Chemical Composition on Performance of P355GH and P355NH steel
The chemical composition directly affects how these steels perform:
P355GH Steel
- Better suited for high-temperature environments
- Stable mechanical properties under heat
- Good weldability
P355NH Steel
- Improved toughness and impact resistance
- Fine-grain structure
- Better performance in low-temperature or dynamic conditions
Applications of P355GH and P355NH steel
Because of their composition differences:
P355GH Steel Applications
- Boilers
- Pressure vessels
- Heat exchangers
- Pipelines for hot liquids
P355NH Steel Applications
- High-strength pressure vessels
- Equipment requiring higher toughness
- Structural components under dynamic loads
The chemical composition of P355GH and P355NH steel determines their suitability for different industrial environments. While both are non-alloy pressure vessel steels, P355GH is ideal for elevated temperature applications, whereas P355NH provides enhanced toughness and fine-grain properties.
As a professional supplier of P355GH and P355NH steel plates, we offer customized sizes, strict quality control, and fast delivery. Contact us today for technical support and competitive pricing.
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What is P355NH material?
P355NH steel is characterised by good weldability and high resistance to brittle cracking.
What is the difference between p355 and S355 steel?
Mechanical Properties: P355GH: Has a minimum yield strength of 355 MPa and is optimized for high-temperature environments in pressure vessels, but has lower toughness in cold conditions. S355J2: Also has a yield strength of 355 MPa but is optimized for structural applications requiring impact toughness.
What is the difference between S355H and s355nh?
Purpose: Similar to S355H, it is used for structural hollow sections, but the "N" indicates that the steel is normalized or normalized rolled, which improves its toughness and weldability by refining the grain structure.
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 P355NH material?
P355NH steel is characterised by good weldability and high resistance to brittle cracking.
What is the difference between p355 and S355 steel?
Mechanical Properties: P355GH: Has a minimum yield strength of 355 MPa and is optimized for high-temperature environments in pressure vessels, but has lower toughness in cold conditions. S355J2: Also has a yield strength of 355 MPa but is optimized for structural applications requiring impact toughness.
What is the difference between S355H and s355nh?
Purpose: Similar to S355H, it is used for structural hollow sections, but the "N" indicates that the steel is normalized or normalized rolled, which improves its toughness and weldability by refining the grain structure.
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.