S355N Steel Meaning and Designation Explained

S355N Steel Meaning and Designation Explained

At Gangsteel, we’re excited to provide a clear explanation of the S355N steel meaning and designation, shedding light on this high-strength, low-alloy structural steel under EN 10025-3. Known for its fine-grain structure, 355 MPa yield strength, and -20°C toughness, S355N is a top choice for structural applications like bridges, cranes, and building frameworks in moderate climates.

As part of the en 10025 3 normalized steel plate family, S355N delivers reliable performance. Gangsteel explains its designation, chemical composition, mechanical properties, and applications, comparing it 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 page.

S355N Steel Meaning and Designation

S355N is a high-strength, low-alloy structural steel defined by the EN 10025-3:2019 standard, with a material number of 1.0545. Its designation breaks down as follows:

• S: Indicates structural steel, designed for load-bearing applications in construction and engineering.
• 355: Specifies the minimum yield strength of 355 MPa for plates up to 16 mm thick, reflecting its capacity to withstand deformation under load.
• N: Denotes normalized or normalized rolled processing, ensuring a fine-grain microstructure with impact toughness tested at -20°C.

The normalization process involves heating the steel to a high temperature and cooling it in air to refine its grain structure, enhancing strength, toughness, and weldability. The material number 1.0545 uniquely identifies S355N in the EN 10025-3 standard, distinguishing it from other grades like en 10025 3 s460n normalized structural steel plate, which has a higher yield strength (460 MPa).

Chemical Composition Supporting S355N Properties

Gangsteel ensures S355N meets EN 10025-3 chemical composition standards, supporting its designation:

Carbon Equivalent (CEV): Capped at 0.43% for plates up to 63 mm, calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15, ensuring excellent weldability. The low-alloy composition, with microalloying elements like niobium and vanadium, supports S355N’s fine-grain structure, similar to en 10025 3 s420n normalized structural steel plate.

Mechanical Properties Supporting S355N Designation

Gangsteel guarantees S355N’s mechanical properties align with its designation:

• Yield Strength: Starts at 355 MPa, reflecting the “355” in its designation, ideal for moderate-load structures.
• Tensile Strength: 470-630 MPa ensures durability under tensile forces.
• Elongation: ≥22% supports complex designs, enhanced by fine-grain structure.
• Impact Toughness: ≥27 J at -20°C, as indicated by “N,” ensures reliability in moderate climates, comparable to en 10025 3 s355nl normalized structural steel plate.
• Hardness: Typically 150-190 HB (Brinell), balancing machinability and durability.
• Density: 7.85 g/cm³ (7850 kg/m³), standard for structural steels, aiding weight calculations.

Delivery Conditions and Specifications

Gangsteel provides S355N with specifications outlined in EN 10025-3:

• Standard: EN 10025-3:2019.
• Condition: Normalized or normalized rolled for consistent microstructure, as denoted by “N.”
• Thickness Range: 6–200 mm, with custom options up to 250 mm.
• Widths: 2000, 2500, or 3000 mm.
• Lengths: Up to 12,000 mm.
• Surface: Hot-rolled, with optional priming for corrosion protection.
• Certifications: EN 10204 3.1/3.2 certificates, ultrasonic testing (UT) per EN 10160, and approvals from ABS, LR, BV, or DNV.
• Z-Quality: Optional Z15, Z25, or Z35 per EN 10164 for through-thickness properties, reducing lamellar tearing risk, similar to en 10025 3 s275n normalized structural steel plate.
• Tolerances: Per EN 10029 for precision.

Welding and Heat Treatment

S355N’s designation supports excellent weldability:

• Welding: Compatible with GMAW and SAW per EN 1011-2. Preheating typically not required for plates <20 mm; optional for thicker plates (100-150°C); post-weld heat treatment (PWHT) at 550-650°C optional.
• Consumables: ER70S-6 for GMAW, EM12K flux with EH14 wire for SAW.
• Weld Quality: Low sulfur (0.025%) and phosphorus (0.030%) ensure reliable welds, matching en 10025 3 s355n normalized structural steel plate.

Applications Leveraging S355N Designation

Gangsteel supplies S355N for projects aligned with its designation:

• Bridges: Load-bearing girders and beams in moderate climates, leveraging 355 MPa yield strength.
• Cranes: Structural components for lifting equipment, benefiting from 470-630 MPa tensile strength.
• Building Frameworks: Columns and trusses in temperate regions, supported by ≥22% elongation.
• Heavy Machinery: Durable chassis components, relying on -20°C toughness as per “N” designation.

For colder climates requiring -50°C toughness, consider en 10025 3 s355nl normalized structural steel plate.

Why Choose Gangsteel?

Gangsteel is your trusted source for S355N:

• Inventory: Extensive stock in China for rapid delivery.
• Sizes: Thicknesses from 6–200 mm, widths up to 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), and 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.

FAQ

What does the S355N designation mean?
S355N’s designation (EN 10025-3) indicates structural steel (“S”), 355 MPa yield strength, and normalized processing (“N”) with -20°C toughness.

How does S355N’s designation support its properties?
The “N” in S355N denotes normalization, ensuring a fine-grain structure for 355 MPa yield strength and ≥27 J toughness at -20°C.

Is S355N weldable per its designation?
Yes, S355N’s CEV ≤0.43% and low impurities ensure reliable welding for structural applications, as per its normalized designation.

What applications align with S355N’s designation?
S355N’s 355 MPa yield and -20°C toughness support bridges, cranes, and frameworks in moderate climates.

How does S355N compare to S460N?
S355N’s 355 MPa yield strength is lower than S460N’s 460 MPa, but its higher elongation (≥22% vs ≥17%) enhances formability.

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

Summary

S355N, designated as a high-strength, low-alloy structural steel under EN 10025-3 with material number 1.0545, offers 355 MPa yield strength and -20°C toughness (≥27 J).

Its “S” (structural), “355” (yield strength), and “N” (normalized) designation reflect its suitability for robust applications like bridges, cranes, and building frameworks in moderate climates.

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.

Compared to S460N, S355N’s lower strength and higher ductility make it a cost-effective choice for general structural projects in temperate regions.