S355NH vs S355J2H Steel Comparison

S355NH vs S355J2H Steel Comparison

At Gangsteel, we’re here to clarify the differences between S355NH vs S355J2H, two high-strength structural steels used in hollow sections for construction and infrastructure projects. S355NH, under EN 10210-1 (hot-finished) or EN 10219-1 (cold-formed), and S355J2H, under the same standards, both offer a minimum yield strength of 355 MPa and -20°C toughness. However, they differ in processing, composition, and specific applications, with S355NH being normalized for enhanced toughness and S355J2H being a non-alloy steel for general use.

As part of the broader EN 10025 and hollow section standards, these grades serve distinct purposes. Gangsteel compares their chemical composition, mechanical properties, and applications, with ties to plate grades like en 10025 3 s355n normalized structural steel plate and en 10025 3 s460n normalized structural steel plate. For more details, contact us or visit our en 10025 3 normalized steel plate page for related grades.

Overview of S355NH and S355J2H

• S355NH (EN 10210-1/EN 10219-1): A high-strength, low-alloy structural steel for hollow sections, normalized or normalized rolled, with 355 MPa yield strength and -20°C toughness. It’s designed for enhanced toughness in demanding structural applications like pipelines and offshore structures.
• S355J2H (EN 10210-1/EN 10219-1): A non-alloy structural steel for hollow sections, hot-finished or cold-formed, with 355 MPa yield strength and -20°C toughness. It’s suited for general construction with simpler processing requirements.

S355NH offers a fine-grain structure for improved toughness, while S355J2H is more cost-effective for less stringent applications.

Chemical Composition Comparison

The chemical composition of S355NH vs S355J2H influences their properties:

Carbon Equivalent (CEV):

• S355NH: ≤0.43% (EN 10210-1).
• S355J2H: ≤0.45% (EN 10210-1).

S355NH’s microalloying elements (Nb, V, Al) and slightly lower carbon content enhance its fine-grain structure and toughness, while S355J2H’s simpler composition makes it more economical, similar to en 10025 3 s355n normalized structural steel plate.

Mechanical Properties Comparison

S355NH vs S355J2H mechanical properties highlight their differences:

• 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 tubular designs.
• Impact Toughness: Both offer ≥27 J at -20°C, suitable for moderate climates.
• Hardness: S355NH’s slightly higher hardness (150-190 HB vs 140-180 HB) reflects its fine-grain structure.
• Wall Thickness: Both support 3–40 mm for hollow sections, versatile for structural applications.

Processing and Fabrication

• S355NH: Normalized for fine-grain microstructure, enhancing toughness for demanding welds. Preheating typically not required for <20 mm; optional for thicker sections (100-150°C); PWHT optional (550-650°C). CEV ≤0.43%.
• S355J2H: Hot-finished or cold-formed, with simpler processing; excellent weldability due to lower CEV (≤0.45%). Preheating rarely needed for thinner sections.

Consumables: Both use ER70S-6 (GMAW) and EM12K flux with EH14 wire (SAW). S355NH’s microalloying ensures better toughness in welds, similar to en 10025 3 s420n normalized structural steel plate.

Applications

• S355NH: Used in demanding structural applications like offshore platforms, pipelines, and wind towers in moderate climates, leveraging its fine-grain structure and enhanced toughness.
• S355J2H: Applied in general construction, building frameworks, railings, and bridges, where cost-effectiveness and standard toughness are sufficient.

S355NH is preferred for critical applications requiring superior toughness, while S355J2H suits cost-sensitive projects. For colder climates, consider en 10025 3 s355nl normalized structural steel plate or S355NLH for hollow sections.

Key Differences Summarized

Why Choose Gangsteel?

Gangsteel supplies S355NH and S355J2H:

• Inventory: Extensive stock in China.
• Sizes: Wall thickness 3–40 mm, diameters/sides up to 2500/500 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 S355NH or S355J2H at en 10025 3 normalized steel plate.

FAQ

What is the main difference in S355NH vs S355J2H?
S355NH is a normalized, low-alloy steel with enhanced toughness due to microalloying, while S355J2H is a non-alloy steel with simpler processing for general use.

How do S355NH and S355J2H toughness compare?
Both offer ≥27 J at -20°C, but S355NH’s fine-grain structure provides superior toughness for critical applications like offshore structures.

Which is better for welding, S355NH or S355J2H?
S355J2H’s slightly higher CEV (≤0.45% vs ≤0.43%) is offset by simpler composition, making both highly weldable, with S355NH better for heavy welds.

What applications suit S355NH vs S355J2H?
S355NH is ideal for offshore platforms and pipelines; S355J2H suits general construction and buildings, similar to en 10025 3 s275n normalized structural steel plate.

How do S355NH and S355J2H costs compare?
S355NH is 10-20% more expensive than S355J2H due to normalization and microalloying.

What certifications support S355NH and S355J2H?
Gangsteel provides both with EN 10204 3.1/3.2, UT testing (EN 10160), and ABS/LR/BV/DNV approvals.

Summary

S355NH and S355J2H are high-strength structural steels for hollow sections under EN 10210-1/EN 10219-1, both offering 355 MPa yield strength and -20°C toughness.

S355NH’s normalized, low-alloy composition with microalloying (Nb, V, Al) provides enhanced toughness for critical applications like offshore platforms and pipelines, while S355J2H’s non-alloy, simpler composition suits cost-effective general construction.

Gangsteel’s inventory supports wall thicknesses of 3–40 mm and global delivery in 7-30 days, with certifications like EN 10204 3.1/3.2.

S355NH is preferred for demanding environments, while S355J2H offers versatility and lower costs, making both essential for tailored structural solutions.