S355N Z25 Through-Thickness Toughness

S355N Z25 Through-Thickness Toughness

At Gangsteel, we’re proud to provide a detailed exploration of S355N Z25 through-thickness toughness, a critical feature of this high-strength, low-alloy structural steel under EN 10025-3, enhanced with Z25 quality per EN 10164. Renowned for its fine-grain structure, 355 MPa yield strength, and -20°C toughness, S355N Z25 is designed to prevent lamellar tearing in thick plates, making it ideal for heavy welded structures like bridges, cranes, and offshore platforms in moderate climates.

As part of the en 10025 3 normalized steel plate family, S355N Z25 delivers reliable performance in demanding applications. Gangsteel examines its chemical composition, mechanical properties, through-thickness toughness, 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.

What is S355N Z25?

S355N Z25 is a high-strength, low-alloy structural steel under EN 10025-3:2019, with Z25 quality per EN 10164, ensuring ≥25% reduction of area in through-thickness tensile testing to prevent lamellar tearing in heavy welds. Its designation, also known as material number 1.0545 with Z25, breaks down as:

• S: Structural steel.
• 355: Minimum yield strength of 355 MPa (≤16 mm).
• N: Normalized or normalized rolled, with impact toughness tested at -20°C.
• Z25: ≥25% reduction of area in through-thickness direction, indicating enhanced ductility perpendicular to the plate surface.

The normalization process refines the grain structure, and Z25 quality enhances through-thickness toughness, making S355N Z25 ideal for thick plates in welded structures. Compared to en 10025 3 s460n normalized structural steel plate, S355N Z25 offers lower strength (355 MPa vs 460 MPa) but superior weld reliability for moderate-load applications.

Chemical Composition Supporting S355N Z25 Through-Thickness Toughness

Gangsteel ensures S355N Z25 meets EN 10025-3 and EN 10164 standards for optimal toughness and weldability:

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 weldability. Low sulfur (≤0.025%) and phosphorus (≤0.030%) minimize inclusions, critical for S355N Z25 through-thickness toughness, similar to en 10025 3 s420n normalized structural steel plate.

Mechanical Properties Supporting S355N Z25

Gangsteel guarantees S355N Z25’s mechanical properties align with its structural and through-thickness requirements:

• Yield Strength: Starts at 355 MPa, ideal for moderate-load structures like bridges.
• Tensile Strength: 470-630 MPa ensures durability under tensile forces.
• Elongation: ≥22% supports complex welded designs.
• Impact Toughness: ≥27 J at -20°C ensures reliability in moderate climates.
• Z25 Through-Thickness Toughness: ≥25% reduction of area per EN 10164, reducing lamellar tearing risk in thick plates.
• Hardness: Typically 150-190 HB (Brinell), balancing machinability and durability.

The Z25 quality ensures enhanced ductility perpendicular to the plate surface, critical for heavy welded structures, comparable to en 10025 3 s355nl normalized structural steel plate.

Delivery Conditions and Specifications

Gangsteel provides S355N Z25 with specifications outlined in EN 10025-3 and EN 10164:

• Standard: EN 10025-3:2019 (base properties), EN 10164:2004 (Z-quality).
• Condition: Normalized or normalized rolled for consistent microstructure.
• Thickness Range: 6–200 mm, with custom options up to 250 mm, suitable for Z25 testing.
• 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, ultrasonic testing (UT) per EN 10160, Z-quality certification, and ABS/LR/BV/DNV approvals.
• Z-Quality: Z25 (≥25% reduction of area), with options for Z15 or Z35, similar to en 10025 3 s275n normalized structural steel plate.
• Tolerances: Per EN 10029 for precision.

Welding and Heat Treatment

S355N Z25’s through-thickness toughness supports robust welding:

• Welding: Compatible with GMAW and SAW per EN 1011-2. Preheating typically not required for <20 mm; optional for thicker plates (100-150°C); PWHT at 550-650°C optional.
• Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW).
• Weld Quality: Low sulfur (0.025%) and phosphorus (0.030%) minimize inclusions, ensuring Z25’s lamellar tearing resistance, matching en 10025 3 s355n normalized structural steel plate.

Applications Leveraging S355N Z25 Through-Thickness Toughness

Gangsteel supplies S355N Z25 for projects requiring high weld reliability:

• Bridges: Thick-plate girders with heavy welds, leveraging Z25’s ≥25% through-thickness ductility to prevent lamellar tearing.
• Cranes: Welded structural components, benefiting from 355 MPa yield strength and -20°C toughness.
• Offshore Platforms: Heavy welded joints in moderate climates, relying on Z25 quality for structural integrity.
• Building Frameworks: Thick columns and trusses with complex welds, supported by ≥22% elongation and Z25 toughness.

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 Z25:

• Inventory: Extensive stock in China for rapid delivery.
• Sizes: Thicknesses 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), Z-quality certification, ABS/LR/BV/DNV approvals.
• Processing: Cutting, welding, bending tailored to your needs.

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

FAQ

What is S355N Z25 through-thickness toughness?
S355N Z25 ensures ≥25% reduction of area in through-thickness tensile testing per EN 10164, preventing lamellar tearing in heavy welds.

How does S355N Z25 toughness support applications?
S355N Z25’s ≥25% through-thickness ductility and ≥27 J at -20°C ensure reliable welds for bridges and offshore platforms.

Is S355N Z25 weldable?
Yes, S355N Z25’s CEV ≤0.43% and low impurities enable reliable welding with GMAW/SAW, minimizing lamellar tearing risks.

What applications use S355N Z25 through-thickness toughness?
S355N Z25 is used in bridges, cranes, and offshore platforms with thick-plate welds, leveraging its Z25 quality.

How does S355N Z25 compare to S460N?
S355N Z25 has lower yield strength (355 MPa vs 460 MPa) but similar Z-quality options, offering cost-effective weld reliability.

What certifications support S355N Z25?
Gangsteel provides S355N Z25 with EN 10204 3.1/3.2, UT testing (EN 10160), Z-quality certification, and ABS/LR/BV/DNV approvals.

Summary

S355N Z25 is a high-strength, low-alloy structural steel under EN 10025-3, offering 355 MPa yield strength, 470-630 MPa tensile strength, and -20°C toughness (≥27 J), with Z25 quality (≥25% through-thickness reduction of area) per EN 10164.

Its fine-grain structure and low impurities ensure excellent weldability and resistance to lamellar tearing, ideal for heavy welded structures like bridges, cranes, and offshore platforms 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 and Z-quality testing.

Compared to S460N, S355N Z25 provides a cost-effective solution with enhanced through-thickness toughness, making it a versatile choice for critical welded applications.