What is EN 10025-3 S355NL Steel Grade?

What is EN 10025-3 S355NL Steel Grade?

EN 10025-3 S355NL is a high-strength, low-alloy structural steel grade specified under the European standard EN 10025-3, which governs normalized or normalized rolled weldable fine grain structural steels. Renowned for its excellent toughness, weldability, and performance in low-temperature environments, the S355NL grade is widely used in demanding applications such as bridges, offshore platforms, and wind turbine towers.

Gangsteel explores the S355NL material, its meaning, properties, chemical composition, mechanical characteristics, and applications, addressing key terms like s355nl, s355nl grade, s355nl material, material s355nl, s355nl meaning, and steel s355nl. For more details, visit our EN 10025-3 S355NL normalized structural steel plate.

Understanding the S355NL Meaning

The s355nl meaning is derived from its designation, which breaks down as follows:

• S: Structural steel, indicating its primary use in load-bearing structures.
• 355: Minimum yield strength of 355 MPa for plates up to 16 mm thick.
• NL: Normalized or normalized rolled, with impact toughness tested at -50°C for superior low-temperature performance.

As a fine grain structural steel, steel s355nl is engineered with a refined microstructure to enhance toughness, weldability, and resistance to brittle fracture. The S355NL grade is part of the EN 10025-3 standard, which emphasizes fine grain steels for applications requiring high strength and durability in challenging conditions.

Chemical Composition of S355NL Material

The material s355nl is carefully formulated to balance strength, toughness, and weldability. Its chemical composition is tightly controlled to minimize impurities and ensure low carbon equivalent (CEV) values, facilitating ease of welding. Below is the chemical composition for S355NL material (ladle analysis and product analysis) as per EN 10025-3:

The Carbon Equivalent (CEV), calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15, is ≤0.43% for thicknesses ≤63 mm. This low CEV ensures that s355nl is highly weldable, reducing the risk of cold cracking during fabrication.

Mechanical Properties of S355NL Steel

The s355nl steel grade offers a robust combination of strength, ductility, and low-temperature toughness, making it suitable for high-stress applications in cold environments. Key mechanical properties include:

• Yield Strength: ≥355 MPa (≤16 mm).
• Tensile Strength: 470-630 MPa.
• Elongation: ≥22% (≤63 mm).
• Impact Toughness: ≥27 J at -50°C (Charpy V-notch, longitudinal).

The mechanical properties vary with thickness, as shown below:

These properties make s355nl grade ideal for applications requiring reliability in sub-zero conditions, such as arctic infrastructure.

Welding and Heat Treatment of S355NL

The material s355nl is highly weldable due to its low CEV (≤0.43%), making it compatible with standard welding processes like GMAW (Gas Metal Arc Welding) and SAW (Submerged Arc Welding), per EN 1011-2 guidelines.

• Preheating: Not required for thicknesses ≤20 mm; 100-150°C recommended for thicker plates to prevent hydrogen-induced cracking.
• Post-Weld Heat Treatment (PWHT): Generally unnecessary; stress relief at 550-650°C may be applied for critical welds.
• Recommended Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW).

This weldability ensures that steel s355nl can be efficiently fabricated into complex structures without compromising integrity.

Applications of S355NL Steel Grade

The s355nl grade is widely used in industries requiring high strength and low-temperature performance:

• Offshore Platforms: Resists fatigue in cold marine environments, ensuring durability in icy conditions.
• Wind Turbine Towers: Supports heavy loads in sub-zero climates, ideal for northern wind farms.
• Bridges and Cranes: Load-bearing components in cold regions, meeting stringent safety standards.
• Pressure Vessels: Suitable for low-temperature storage or processing systems.

Its combination of high strength-to-weight ratio, -50°C toughness, and excellent weldability makes s355nl a preferred choice for Eurocode 3-compliant designs. For alternative grades, explore EN 10025-3 S420NL normalized structural steel plate or EN 10025-3 S460NL normalized structural steel plate.

Equivalent Grades of S355NL

S355NL has equivalents in various international standards, though slight differences exist due to processing or testing requirements:

For a related grade, see EN 10025-3 S355N normalized structural steel plate.

Why Choose Gangsteel for S355NL Steel?

Gangsteel is a leading producer and exporter of s355nl steel, offering:

• Inventory: Extensive stock of S355NL and related grades in China for immediate availability.
• Sizes: Thickness 6–250 mm, widths 2000/2500/3000 mm, lengths up to 12,000 mm.
• Delivery: 7-30 days to Europe, Asia, Middle East, and Americas.
• Certifications: EN 10204 3.1/3.2 certificates, UT testing (EN 10160), and ABS/LR/BV/DNV approvals.
• Processing: Cutting, welding, and bending to meet project specifications.

Request a quote for EN 10025-3 S355NL normalized structural steel plate.

FAQ

What is the S355NL steel grade?

S355NL is a high-strength, fine-grained structural steel under EN 10025-3, with 355 MPa yield strength and -50°C impact toughness, ideal for cold-climate structures.

What does the S355NL meaning signify?

The designation indicates structural steel (S), 355 MPa yield strength, and normalized condition with -50°C toughness (NL).

What are the key properties of S355NL material?

Yield strength ≥355 MPa, tensile strength 470-630 MPa, elongation ≥22%, and impact toughness ≥27 J at -50°C.

Is steel S355NL weldable?

Yes; its CEV ≤0.43% supports GMAW/SAW welding with minimal preheating (100-150°C for >20 mm).

What are the applications of the S355NL grade?

Used in offshore platforms, wind towers, bridges, and pressure vessels in cold environments.

How does S355NL compare to S355J2?

S355NL is normalized fine-grain steel tested at -50°C, while S355J2 is hot-rolled, tested at -20°C, less suited for extreme cold. See EN 10025-3 S420NL normalized structural steel plate.

What is the ASTM equivalent of material S355NL?

ASTM A572 Grade 65 (strength) or A633 Grade E (toughness) are approximate equivalents.

For alternative grades, check EN 10025-3 S275N normalized structural steel plate.