S355N vs S355NL Steel Comparison

S355N vs S355NL Steel Comparison

At Gangsteel, we’re here to clarify the differences between S355N vs S355NL, two high-strength, low-alloy structural steels under EN 10025-3, each tailored for specific structural applications. Both S355N and S355NL offer a minimum yield strength of 355 MPa, but they differ in toughness, with S355N tested at -20°C and S355NL at -50°C, making S355NL ideal for colder climates.

As part of the en 10025 3 normalized steel plate family, these grades serve distinct purposes in bridges, cranes, and offshore structures. Gangsteel compares their chemical composition, mechanical properties, and applications, with ties 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, ideal for moderate climates like temperate Europe (e.g., bridges, cranes).
• 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 like Arctic regions (e.g., offshore platforms, wind towers).

Both grades are designed for high-strength structural plates, but S355NL’s enhanced low-temperature toughness makes it better for extreme conditions, while S355N is more cost-effective for milder environments.

Chemical Composition Comparison

The chemical composition of S355N vs S355NL influences their toughness and weldability:

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 its toughness and weldability, making it a stronger choice for cold climates, similar to en 10025 3 s420n normalized structural steel plate.

Mechanical Properties Comparison

S355N vs S355NL mechanical properties highlight their differences:

• Yield Strength: Both offer 355 MPa, ideal for moderate-load structures like bridges.
• Tensile Strength: Identical range (470-630 MPa) ensures comparable durability.
• Elongation: Both provide ≥22%, supporting complex structural 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 (Brinell), 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 enhanced toughness; similar welding requirements. S355NL’s 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: Used in bridges, cranes, and building frameworks in moderate climates (e.g., temperate Europe), leveraging 355 MPa yield strength and -20°C toughness.
• S355NL: Suited for offshore platforms, wind towers, and bridges in cold climates (e.g., Arctic regions or northern Europe), relying on -50°C toughness.

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

Key Differences Summarized

Why Choose Gangsteel?

Gangsteel supplies S355N and S355NL:

• Inventory: Extensive stock in China for rapid delivery.
• Sizes: Thicknesses 6–200 mm, widths 2000/2500/3000 mm, lengths up to 12,000 mm.
• Delivery: Ships globally in 7-30 days.
• Certifications: EN 10204 3.1/3.2, UT testing (EN 10160), ABS/LR/BV/DNV approvals.
• Processing: Cutting, welding, and bending tailored to your needs.

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

FAQ

What is the main difference in S355N vs S355NL?
S355N offers -20°C toughness for moderate climates, while S355NL provides -50°C toughness for cold climates, both with 355 MPa yield strength.

How does S355N vs S355NL toughness compare?
S355NL’s ≥27 J at -50°C outperforms S355N’s ≥27 J at -20°C, making it ideal for arctic environments like offshore platforms.

Which is better for welding, S355N or S355NL?
S355NL’s lower sulfur (0.020% vs 0.025%) and phosphorus (0.025% vs 0.030%) slightly improve weldability, though both have CEV ≤0.43%.

What applications suit S355N vs S355NL?
S355N is ideal for bridges and cranes in moderate climates; S355NL suits offshore platforms and wind towers in cold climates.

How do S355N and S355NL costs compare?
S355NL is slightly more expensive due to enhanced toughness and lower impurities, but both are cost-effective compared to S460N.

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, both offering 355 MPa yield strength, 470-630 MPa tensile strength, and ≥22% elongation.

S355N, with -20°C toughness (≥27 J), is ideal for moderate climates like temperate Europe, while S355NL’s -50°C toughness excels in cold climates like Arctic regions.

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 lower impurities enhance weldability and toughness for demanding applications, while S355N offers a cost-effective solution for milder environments, providing tailored options for structural projects.