S355N and S355NL Steel Guide

S355N and S355NL Steel Guide

At Gangsteel, we’re excited to present a comprehensive guide to S355N and S355NL steel, two high-strength, low-alloy structural steels under EN 10025-3, each tailored for specific structural applications. S355N, with 355 MPa yield strength and -20°C toughness, is ideal for moderate climates, while S355NL, with similar strength and enhanced -50°C toughness, excels in cold climates.

As part of the en 10025 3 normalized steel plate family, both grades deliver reliable performance for bridges, cranes, and offshore structures. Gangsteel explores their chemical composition, mechanical properties, and applications, comparing them to grades like en 10025 3 s420n normalized structural steel plate and en 10025 3 s460n normalized structural steel plate. For more details, contact us or visit our en 10025 3 s355n normalized structural steel plate or en 10025 3 s355nl normalized structural steel plate pages.

Overview of S355N and S355NL

• S355N (EN 10025-3, 1.0545): A normalized or normalized rolled fine-grain steel with 355 MPa yield strength and -20°C toughness, designed for high-load applications like bridges and cranes in moderate climates (e.g., temperate Europe).
• S355NL (EN 10025-3, 1.0546): A normalized or normalized rolled fine-grain steel with 355 MPa yield strength and -50°C toughness, suited for cold climates (e.g., Arctic regions, offshore platforms).

Both grades are optimized for structural plates, with S355NL offering superior low-temperature toughness for extreme conditions, while S355N is cost-effective for milder environments.

Chemical Composition Comparison

The chemical composition of S355N and S355NL drives their performance:

Carbon Equivalent (CEV):

• S355N: ≤0.43% (≤63 mm).
• S355NL: ≤0.43% (≤63 mm).

S355NL’s lower carbon (0.18% vs 0.20%), sulfur (0.020% vs 0.025%), and phosphorus (0.025% vs 0.030%) enhance toughness and weldability, making it ideal for cold climates, similar to en 10025 3 s420n normalized structural steel plate.

Mechanical Properties Comparison

S355N and S355NL mechanical properties highlight their suitability for different environments:

• Yield Strength: Both offer 355 MPa, ideal for moderate-load structures.
• Tensile Strength: Identical range (470-630 MPa) ensures comparable durability.
• Elongation: Both provide ≥22%, supporting complex designs.
• Impact Toughness: S355NL’s ≥27 J at -50°C outperforms S355N’s ≥27 J at -20°C, making it suitable for colder climates.
• Hardness: Both typically 150-190 HB, balancing machinability and durability.
• Thickness: Both support up to 200 mm, versatile like en 10025 3 s355n normalized structural steel plate.

Processing and Fabrication

• S355N: Normalized for consistent microstructure, suited for standard welding. Preheating typically not required for <20 mm; optional for thicker plates (100-150°C); PWHT optional (550-650°C). CEV ≤0.43%.
• S355NL: Normalized with lower impurities for superior toughness; similar welding requirements. Lower sulfur and phosphorus improve weld quality. CEV ≤0.43%.

Consumables: Both use ER70S-6 (GMAW) and EM12K flux with EH14 wire (SAW). S355NL’s lower impurities reduce weld imperfections, similar to en 10025 3 s275n normalized structural steel plate.

Applications

• S355N: Ideal for bridges, cranes, and building frameworks in moderate climates (e.g., temperate Europe), leveraging 355 MPa yield strength and -20°C toughness. Examples include highway bridges and industrial structures.
• S355NL: Suited for offshore platforms, wind towers, and bridges in cold climates (e.g., Arctic regions, northern Europe), relying on -50°C toughness. Examples include offshore rigs and cold-region infrastructure.

S355NL is preferred for sub-zero conditions, while S355N is cost-effective for milder environments. For higher strength, consider en 10025 3 s460n normalized structural steel plate.

Delivery Conditions and Specifications

Gangsteel provides S355N and S355NL with:

• Standard: EN 10025-3:2019.
• Condition: Normalized or normalized rolled.
• Thickness Range: 6–200 mm, custom up to 250 mm.
• Widths: 2000/2500/3000 mm.
• Lengths: Up to 12,000 mm.
• Surface: Hot-rolled, optional priming.
• Certifications: EN 10204 3.1/3.2, UT testing (EN 10160), ABS/LR/BV/DNV approvals.
• Z-Quality: Optional Z15, Z25, Z35 per EN 10164.
• Tolerances: Per EN 10029.

Why Choose Gangsteel?

Gangsteel is your trusted source for S355N and S355NL:

• Inventory: Extensive stock in China.
• Sizes: Thicknesses 6–200 mm, widths up to 3000 mm, lengths up to 12,000 mm.
• Delivery: 7-30 days globally.
• Certifications: EN 10204 3.1/3.2, UT testing (EN 10160), ABS/LR/BV/DNV approvals.
• Processing: Cutting, welding, bending.

Contact us for en 10025 3 s355n normalized structural steel plate or en 10025 3 s355nl normalized structural steel plate.

FAQ

What are S355N and S355NL steels?
S355N and S355NL are EN 10025-3 structural steels with 355 MPa yield strength; S355N offers -20°C toughness for moderate climates, S355NL -50°C for cold climates.

How does toughness differ between S355N and S355NL?
S355NL’s ≥27 J at -50°C outperforms S355N’s ≥27 J at -20°C, making it ideal for Arctic environments.

Are S355N and S355NL weldable?
Both have CEV ≤0.43%; S355NL’s lower sulfur (0.020% vs 0.025%) and phosphorus (0.025% vs 0.030%) enhance weldability.

What are the applications of S355N and S355NL?
S355N suits bridges and cranes in moderate climates; S355NL is for offshore platforms and wind towers in cold climates.

How do S355N and S355NL compare to S460N?
Both have lower yield strength (355 MPa vs 460 MPa) than S460N but offer higher elongation (≥22% vs ≥17%) for formability.

What certifications support S355N and S355NL?
Gangsteel provides both with EN 10204 3.1/3.2, UT testing (EN 10160), and ABS/LR/BV/DNV approvals.

Summary

S355N and S355NL are high-strength, low-alloy structural steels under EN 10025-3, offering 355 MPa yield strength, 470-630 MPa tensile strength, and ≥22% elongation.

S355N, with -20°C toughness (≥27 J), is ideal for bridges and cranes in moderate climates, while S355NL, with -50°C toughness, excels in cold climates like offshore platforms.

Gangsteel’s inventory supports thicknesses from 6–200 mm, with global delivery in 7-30 days and certifications like EN 10204 3.1/3.2.

S355NL’s enhanced toughness suits extreme conditions, while S355N offers cost-effective performance, providing versatile solutions for structural projects.