s275n vs s275nl different

S275N vs S275NL: Key Differences in EN 10025-3 Normalized Steel Grades

As a premier exporter and manufacturer of high-quality structural steel plates, Gangsteel specializes in producing EN 10025-3 compliant materials, including the versatile S275N and S275NL steel grades.

Both are normalized fine-grain structural steels designed for welded constructions, offering excellent weldability and strength.

However, S275NL provides enhanced low-temperature toughness compared to S275N, making it suitable for harsher environments.

Our plates are delivered in normalized or normalized rolled conditions to ensure superior performance.

For a comprehensive overview of our en 10025 3 normalized steel plate offerings, explore our full range.

Overview of S275N and S275NL

S275N and S275NL are low-alloy, fine-grain structural steels under EN 10025-3 (designations 1.0490 and 1.0491, respectively). The "S" indicates structural steel, "275" denotes a minimum yield strength of 275 MPa, "N" means normalized delivery, and the "L" in S275NL signifies extended low-temperature impact testing.

While they share identical yield and tensile strength requirements, the key distinction lies in Charpy V-notch impact energy testing: S275N at -20°C versus S275NL at -50°C. This makes S275NL ideal for arctic or sub-zero applications, whereas S275N suffices for moderate climates. Compared to higher grades like en 10025 3 s355n normalized structural steel plate, both offer cost-effective options for weldable structures.

Gangsteel produces both in thicknesses up to 250 mm, with full compliance to CEV limits for optimal fabrication.

Chemical Composition Differences

The chemical profiles are similar but S275NL features tighter controls on carbon, phosphorus, and sulfur for improved toughness and reduced brittleness at low temperatures (heat analysis max %, nominal thickness ≤ 100 mm).

*Note: Lower C, P, and S in S275NL enhance grain refinement and weldability in cold conditions. For long products, P and S may increase by 0.005%.

Mechanical Properties Comparison

Mechanical properties are nearly identical across thicknesses, with the primary variance in impact toughness. Below is a consolidated table for normalized (+N) condition (minimum values; elongation per Lo = 5.65 √So).

*Notes: Impact values are minimums; S275N values at -20°C are higher to compensate for warmer testing. S275NL's lower values at -50°C still ensure superior cold performance. These specs make both grades versatile, but S275NL outperforms in sub-zero scenarios.

Applications and When to Choose Each

• S275N: Suitable for general welded structures in temperate climates, such as buildings, machinery frames, and bridges in mild weather. Cost-effective for non-extreme low-temp exposure.
• S275NL: Preferred for harsh, cold environments like offshore platforms, arctic infrastructure, cranes in northern regions, and pressure vessels where fracture risk at -50°C must be minimized.

For projects needing higher strength, consider en 10025 3 s275nl normalized structural steel plate or en 10025 3 s275n normalized structural steel plate.

Why Choose Gangsteel for S275N and S275NL?

Gangsteel offers both grades with ISO-certified quality, precise normalization, and global export readiness. Dual-certified plates available for seamless substitutions.

Summary

S275N and S275NL share identical strength (205–275 MPa yield) and weldability under EN 10025-3 but differ primarily in impact toughness: -20°C for S275N versus -50°C for S275NL, with S275NL's tighter chemistry enhancing cold ductility. Select S275N for moderate conditions and S275NL for extreme cold, ensuring optimal safety and performance in structural applications.

FAQ

What is the main difference between S275N and S275NL?

The primary distinction is the Charpy V-notch impact testing temperature: S275N requires a minimum of 47 J longitudinal at -20°C (31 J transverse), while S275NL demands 27 J at -50°C (16 J transverse). This makes S275NL more suitable for sub-zero environments, as it guarantees toughness in colder conditions without altering other mechanical properties like yield or tensile strength.

Are the chemical compositions of S275N and S275NL identical?

No, S275NL has stricter limits: maximum carbon at 0.16% (vs. 0.18% for S275N), phosphorus at 0.025% (vs. 0.030%), and sulfur at 0.020% (vs. 0.025%). These reductions in S275NL improve grain refinement, reduce brittleness, and enhance weld crack resistance in low temperatures, while both maintain a CEV ≤ 0.40 for excellent weldability. Other elements like manganese (0.50–1.50%) and silicon (≤0.40%) are the same.

Do S275N and S275NL have the same mechanical properties besides impact testing?

Yes, for thicknesses up to 250 mm, both exhibit the same minimum yield strength (decreasing from 275 MPa at ≤16 mm to 205 MPa at 200–250 mm), tensile strength (370–510 MPa up to 100 mm, 350–480 MPa beyond), and elongation (23–24%). The normalization process ensures a fine-grain structure in both, but S275NL's lower impact values at -50°C still provide better overall cold performance than S275N at equivalent temperatures.

In what applications should I choose S275N over S275NL?

Opt for S275N in moderate climates or non-critical low-temp structures, such as indoor machinery, standard bridges, or building frameworks where temperatures rarely drop below -20°C. It's more economical while meeting EN 10025-3 standards for weldable fine-grain steel, saving costs without compromising strength in temperate zones.

When is S275NL necessary, and what are its advantages in cold environments?

S275NL is essential for applications exposed to -50°C or lower, like offshore oil rigs, arctic pipelines, northern cranes, or wind farm foundations, where brittle fracture risks increase. Its advantages include superior ductility and impact resistance in extreme cold—maintaining 27 J at -50°C versus S275N's potential drop-off—leading to higher safety margins, reduced failure rates, and compliance with stringent codes like Eurocode 3 for cold regions.

Can S275N and S275NL be welded similarly?

Absolutely; both have low CEV (≤0.40) for excellent weldability without preheating up to 40 mm thickness. Use matching low-hydrogen electrodes (e.g., E7018) and limit interpass temperatures to 200°C. For S275NL in cold service, post-weld stress relief at 550–650°C may be recommended more often to preserve toughness, but procedures per EN 1011-2 apply to both.

What are the equivalent grades for S275N and S275NL?

S275N equivalents include DIN StE 285 and ASTM A572 Gr. 50; S275NL aligns with DIN TStE 285 and ASTM A633 Gr. A. Both share JIS SM490B. Always verify impact equivalence for substitutions, as S275NL's -50°C rating may require normalized delivery in equivalents.