Whick is better choose between the P275N and P275NL2 steel plates

When selecting materials for pressure vessels and boilers, choosing between P275N Material and P275NL2 steel plates is a common challenge.

P275N

Both grades belong to the EN 10028-3 and share similar strength levels, but they differ significantly in impact toughness, temperature performance, and application scenarios.

Understanding these differences is essential to ensure safety, cost efficiency, and long-term performance in your project.

Both P275N pressure vessel steel and P275NL2 are normalized fine-grained steels designed for pressure equipment such as boilers, tanks, and pipelines.

P275N Material: Standard normalized steel for moderate temperature applications

P275NL2 steel plate: Enhanced version with superior low-temperature toughness

While their chemical compositions are similar, their impact testing requirements and service environments differ.

From the table, it is clear that both steels offer similar strength, but P275NL2 provides significantly better toughness at low temperatures.

The most critical difference between the two materials lies in their impact resistance at different temperatures.

P275N pressure vessels steel is typically tested at 0°C, making it suitable for standard environments.

P275NL2 steel plate is tested at -50°C, ensuring reliable performance in extreme cold conditions.

This means that P275NL2 has a much lower risk of brittle fracture, which is crucial for safety in cold climates or cryogenic applications.

P275N Material is widely used in general industrial applications where extreme cold resistance is not required.

Typical Applications:

• Boiler manufacturing (steam drums, shells, pipelines)
• Pressure vessels and storage tanks
• Oil and gas containers
• Heat exchangers
• Power plant equipment

Advantages:

• Cost-effective solution
• Good weldability and formability
• Stable performance under moderate temperatures
• Wide availability and shorter delivery time

For most standard projects, P275N pressure vessels steel provides an excellent balance between performance and cost.

P275NL2 steel plate is specifically designed for low-temperature and high-safety applications.

Typical Applications:

• LNG and cryogenic storage tanks
• Low-temperature pressure vessels
• Arctic pipelines and offshore platforms
• Cold-region energy infrastructure

Advantages:

• High impact toughness at -50°C
• Reduced risk of brittle fracture
• Improved safety in extreme environments
• Suitable for critical and high-risk projects

When safety under low temperatures is a priority, P275NL2 is the preferred choice.

Cost is another important factor when choosing between these two materials.

• P275N Material: Lower production cost and more economical for large-scale use
• P275NL2 steel plate: Higher cost due to stricter testing and enhanced performance

For projects operating in normal environments, choosing P275NL2 may lead to unnecessary cost increases. However, using P275N in low-temperature conditions can result in serious safety risks.

The selection should be based on your actual working conditions:

Choose P275N if:

• Operating temperature is above 0°C
• Application is standard pressure vessel or boiler
• Budget control is important

Choose P275NL2 if:

• Operating temperature is below -20°C or down to -50°C
• Project requires high safety standards
• Application involves LNG, offshore, or cold climates

In real engineering projects, many failures are not caused by insufficient strength, but by inadequate toughness at low temperatures. This is why standards like EN 10028-3 define different grades such as N, NL1, and NL2.

Choosing the correct material grade is essential to ensure:

• Structural integrity
• Long service life
• Compliance with international standards
• Safe operation under real working conditions

Both P275N pressure vessels steel and P275NL2 steel plates are reliable materials under the EN 10028-3 standard. The key difference lies in their impact toughness and temperature suitability.

• P275N Material is ideal for general applications with cost advantages
• P275NL2 steel plate is essential for low-temperature environments requiring higher safety

Selecting the right steel grade is critical for ensuring both performance and cost efficiency. As a professional supplier, we provide high-quality P275N pressure vessels steel and P275NL2 steel plates with full certification and fast delivery.

Contact us today to get expert advice and the best material solution for your pressure vessel and boiler projects.

Contact now to get P275N steels Quote

What are the core differences between P275N, P275NH, P275NL1, and P275NL2?

The core differences lie in impact test temperature and applicable working conditions. All four grades have a minimum yield strength of ≥275MPa (for thickness ≤16mm) and comply with the EN 10028-3 standard:

P275N: Impact test at -20°C, suitable for normal-temperature pressure vessels and general industrial pipelines;

P275NH: Impact test at -20°C, optimized for high-temperature performance, adaptable to medium-to-high temperature pressure equipment below 350°C;

P275NL1: Impact test at -40°C, suitable for low-temperature storage tanks and separators in cold regions;

P275NL2: Impact test at -50°C, offering the best ultra-low temperature toughness, adaptable to cryogenic equipment such as liquid nitrogen/LNG systems.

What are the corresponding numerical designations for these four grades?

P275N: 1.0483;

P275NH: 1.0485;

P275NL1: 1.0488;

P275NL2: 1.1104.

Does thickness affect performance?

Yes, it does. When the thickness exceeds 16mm, the yield strength gradually decreases (e.g., ≥245MPa for 63~100mm), and the low-temperature toughness also slightly declines. For ultra-low temperature working conditions with thickness ＞40mm, it is recommended to prioritize P275NL2 and increase the sampling ratio for impact tests.

What are the key mechanical property indicators of the four grades?

Yield Strength (ReH): ≥275MPa for thickness ≤16mm, slightly decreasing with increasing thickness (e.g., ≥255MPa for 40~63mm);

Tensile Strength (Rm): 410~560MPa;

Impact Energy (KV): ≥27J for each corresponding impact temperature (regular supply meets ≥40J to enhance safety redundancy);

Elongation (A): ≥22%~24% (adjusted with thickness).

What is the range of available dimensions?

Thickness: 6mm~300mm;

Width: 1500mm~4800mm;

Length: 6000mm~18000mm;

Customized cutting, drilling, and beveling services are available, with a minimum cutting size of 500×500mm.

How is the weldability, and what are the welding recommendations?

It has excellent weldability (CEV ≤0.43%), with recommended solutions:

Welding Consumables: E5515-C1 for manual arc welding, H08MnA+F55A4 flux for submerged arc welding, and ER50-6 for gas metal arc welding;

Preheating Requirement: No preheating required for thickness ≤30mm; preheat to 100~150°C for thickness ＞30mm;

Interpass Temperature: ≤250°C, with heat input controlled at 15~35kJ/cm;

Post-Weld Heat Treatment (PWHT): Recommended for thick plates (＞50mm) – stress relief annealing at 580~620°C for 2 hours.

Can the P275 series be substituted for ASTM A516 Gr70 (American standard) or Q345R (Chinese standard)?

vs. ASTM A516 Gr70: Similar strength, but the P275 series offers better low-temperature toughness . The P275 series is preferred for European projects, while ASTM A516 Gr70 is suitable for North American projects;

vs. Q345R (GB 713): Q345R has higher yield strength (≥345MPa), but the P275 series excels in low-temperature performance (-20°C impact) and high-temperature stability. For international projects, it is recommended to select according to the EN standard first.

What are the differences between P275NL1/NL2 and 16MnDR (Chinese standard)?

16MnDR (GB 3531): Impact test at -40°C, yield strength ≥315MPa, suitable for domestic low-temperature projects;

P275NL1: Impact test at -40°C, yield strength ≥275MPa, belonging to the European standard system with higher international recognition;

P275NL2: Impact test at -50°C, offering better low-temperature toughness than 16MnDR, adaptable to more severe cryogenic working conditions.