What is S355J2G3 steel?

What is S355J2G3 Steel?

Overview of S355J2G3 Steel

S355J2G3 is a non-alloy structural steel grade previously specified under the European standard EN 10025:1990, which has been superseded by EN 10025-2 in later revisions. It is a high-strength, low-carbon steel widely used in general construction and engineering applications due to its good strength, weldability, and affordability. The designation "S355J2G3" breaks down as follows:

• S: Structural steel.
• 355: Minimum yield strength of 355 MPa for thicknesses up to 16 mm.
• J2: Impact toughness tested at -20°C with a minimum of 27 J (Charpy V-notch, longitudinal).
• G3: Normalized or normalized rolled (as per the older standard; later revisions may vary).

Although S355J2G3 is an older designation, it is closely aligned with the modern S355J2 grade under EN 10025-2, which is widely used today. S355J2G3 was known for its versatility in temperate climates, offering a balance of strength and ductility for structural applications. For related modern grades, explore our EN 10025-3 S355NL normalized structural steel plate for enhanced low-temperature performance.

Chemical Composition of S355J2G3

The chemical composition of S355J2G3 (per EN 10025:1990) is designed to ensure good weldability and mechanical performance. Below is a typical composition (maximum values, unless specified):

Carbon Equivalent (CEV): Typically ≤0.45% (calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15), ensuring good weldability for standard processes. Compared to fine-grain steels like EN 10025-3 S355N normalized structural steel plate, S355J2G3 has less stringent controls on grain-refining elements (e.g., no mandatory aluminum or niobium).

Mechanical Properties of S355J2G3

S355J2G3 offers reliable strength and moderate low-temperature toughness, suitable for general structural use. Key mechanical properties (per EN 10025:1990) are:

These properties align closely with modern S355J2 under EN 10025-2, though S355J2G3’s normalization (G3) may not always be required in newer specifications.

Comparison with Modern Grades

S355J2G3 is essentially equivalent to S355J2 in EN 10025-2 (2004 and later), with minor updates in composition and delivery conditions. However, it differs from fine-grain grades under EN 10025-3:

• S355NL (EN 10025-3): Normalized, fine-grain steel with impact toughness at -50°C, better for cold climates. See EN 10025-3 S355NL normalized structural steel plate.
• S355N (EN 10025-3): Similar to S355NL but tested at -20°C, closer to S355J2G3 but with finer grain control.

S355J2G3 is less suited for sub-zero conditions compared to NL grades but more cost-effective for temperate environments.

Welding and Heat Treatment

S355J2G3 is highly weldable due to its low CEV (≤0.45%):

• Welding: Suitable for GMAW or SAW with fillers like ER70S-6 (GMAW) or EM12K flux with EH14 wire (SAW). Preheating (100-150°C) is recommended for thicknesses >25 mm to avoid hydrogen cracking.
• Post-Weld Heat Treatment (PWHT): Rarely needed; stress relief at 550-650°C for critical welds.

Compared to fine-grain steels like EN 10025-3 S420NL normalized structural steel plate, S355J2G3 may require slightly more preheating due to higher allowable impurities.

Applications of S355J2G3

S355J2G3 is used in:

• Building Structures: Columns, beams, and trusses in commercial and industrial buildings.
• Bridges: Secondary components in temperate climates.
• Machinery: Frames and supports for industrial equipment.
• General Fabrication: Welded assemblies where cost and strength are balanced.

Its -20°C toughness suits moderate climates but is less ideal for extreme cold compared to EN 10025-3 S460NL normalized structural steel plate.

Equivalent Grades

S355J2G3 (and its modern equivalent S355J2) aligns with:

• ASTM / ASME: A572 Grade 50 (approximate, yield ~345 MPa).
• Chinese GB: Q345B (similar strength, -20°C toughness).
• JIS: SM490A/B (comparable properties).
• DIN: St 52-3U (older German standard).

For higher-strength or colder applications, consider EN 10025-3 S420N normalized structural steel plate.

Why Choose Gangsteel for S355J2G3 (S355J2)?

Gangsteel supplies S355J2 (modern equivalent of S355J2G3) and related grades:

• Inventory: Ample stock in China for rapid delivery.
• Sizes: Thickness 6–250 mm, widths 2000/2500/3000 mm, lengths up to 12,000 mm.
• Delivery: 7-30 days globally to Europe, Asia, Middle East, Americas.
• 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 S355NL normalized structural steel plate as an alternative for low-temperature needs.

FAQ

What is S355J2G3 steel used for?

General construction, bridges, machinery, and welded assemblies in moderate climates.

Is S355J2G3 the same as S355J2?

Yes, S355J2 is the modern equivalent under EN 10025-2, with minor specification updates.

How does S355J2G3 differ from S355NL?

S355J2G3 is hot-rolled, tested at -20°C; S355NL is normalized fine-grain, tested at -50°C for colder climates. See EN 10025-3 S355NL normalized structural steel plate.

Is S355J2G3 weldable?

Yes; CEV ≤0.45% supports GMAW/SAW with minimal preheating (100-150°C for >25 mm).

What is the ASTM equivalent of S355J2G3?

A572 Grade 50 (yield ~345 MPa) is closest but less focused on low-temp toughness.

Can S355J2G3 be used in cold climates?

Suitable for -20°C; for colder conditions, use S355NL or EN 10025-3 S275NL normalized structural steel plate.

What is the maximum thickness of S355J2G3?

Typically up to 250 mm, with adjusted properties for thicker sections.

Explore related grades like EN 10025-3 S275N normalized structural steel plate.