grade s420nl from en 10025-3

As a premier exporter and manufacturer of high-quality structural steel plates, Gangsteel specializes in producing EN 10025-3 compliant materials, including the versatile S420NL steel grade.

S420NL is a normalized fine-grain structural steel designed for welded constructions requiring enhanced toughness at low temperatures, down to -50°C.

Ideal for heavy-duty applications in bridges, cranes, and offshore structures, our S420NL plates are delivered in normalized or normalized rolled conditions to ensure superior weldability and impact resistance.

For a comprehensive overview of our en 10025 3 normalized steel plate offerings, explore our full range.

What is Grade S420NL from EN 10025-3?

Grade S420NL from EN 10025-3 is a high-strength, low-alloy (HSLA), fine-grain structural steel specified in the European standard EN 10025-3:2019 for hot-rolled products of structural steels with technical delivery conditions for normalized/normalized rolled weldable fine grain structural steels. The designation breaks down as "S" for structural steel, "420" for a minimum yield strength of 420 MPa (for thicknesses ≤ 16 mm), and "NL" for normalized delivery with low-temperature impact testing at -50°C (27 J minimum longitudinal). This grade is optimized for environments demanding high ductility and resistance to brittle fracture in cold conditions, distinguishing it from milder variants like S355NL.

Gangsteel produces S420NL plates in thicknesses up to 250 mm, with precise control over chemical composition to meet CEV limits for optimal weldability. Our plates are rigorously tested to comply with international standards, ensuring reliability for global projects.

Chemical Composition of Grade S420NL from EN 10025-3

The chemical makeup of S420NL is carefully balanced to provide excellent strength, ductility, and resistance to brittle fracture. Below is the product analysis for nominal thicknesses ≤ 100 mm, with a maximum Carbon Equivalent Value (CEV) of 0.48 (or up to 0.50 in some specifications).

*Note: For long products, P and S may be 0.005% higher. If N-binding elements are present, the Al minimum does not apply. Cu above 0.4% may affect hot forming.

This low carbon and controlled alloying ensure minimal risk of cracking during welding.

Mechanical Properties of Grade S420NL from EN 10025-3

S420NL exhibits robust mechanical characteristics, with properties varying by thickness to accommodate diverse fabrication needs. All values are for normalized (+N) condition. The table below consolidates yield strength, tensile strength, elongation, and Charpy V-Notch impact energy (longitudinal and transverse at key temperatures, with focus on -50°C minimums).

*Notes: Elongation based on Lo = 5.65 √So. Impact values are minimums; higher at warmer temperatures. These properties position S420NL as a cost-effective choice for structures needing high toughness, outperforming standard S420JR in sub-zero conditions.

Heat Treatment Guide for S420NL Steel Grade

S420NL steel is primarily supplied in the normalized (+N) or normalized rolled condition as per EN 10025-3, which refines the grain structure for improved toughness and weldability.

Normalization Process

• Heating Temperature: Austenitize at 880–920°C (uniform throughout the thickness).
• Soaking Time: Hold for approximately 1 hour per 25 mm of thickness, minimum 30 minutes.
• Cooling: Air cool to room temperature at a controlled rate to avoid excessive hardening.
• Purpose: Refines ferrite-pearlite structure, enhances ductility, and ensures compliance with mechanical properties post-delivery.

If post-delivery heat treatment is needed (e.g., after hot forming), re-normalize to maintain properties. Avoid quenching unless specified, as it may alter toughness.

Welding Heat Treatment Guidelines

• Preheating: Not required for thicknesses ≤ 50 mm; recommend 100–150°C for thicker sections to prevent cold cracking, based on CEV ≤ 0.48.
• Interpass Temperature: Maximum 200°C to preserve fine grain.
• Post-Weld Heat Treatment (PWHT): Optional stress-relief at 550–650°C for 1 hour per 25 mm thickness, followed by slow cooling. Not typically needed due to low hardenability.
• Hot Forming: Perform above 850°C; re-normalize if forming temperature drops below 720°C.

Always consult EN 1011-2 for welding recommendations. Gangsteel provides plates optimized for these processes to minimize heat treatment needs.

Applications of S420NL Steel Grade

S420NL is widely used in:

• Heavy Engineering: Cranes, earthmoving equipment, and load-bearing frameworks.
• Infrastructure: Bridges, viaducts, and offshore platforms where low-temperature ductility is critical.
• Construction: Welded structures in shipbuilding and pressure vessels.

For higher strength needs, consider upgrading to en 10025 3 s460n normalized structural steel plate or en 10025 3 s460nl normalized structural steel plate.

S420NL Steel Grade Equivalent JIS

The JIS equivalent to S420NL steel grade is SM570 (JIS G 3106), a rolled steel for welded structures with 460 MPa yield and similar weldability; specify normalization and -50°C impact testing for full equivalence.

Equivalent Grades to S420NL

Why Choose Gangsteel for S420NL Steel Grade?

With state-of-the-art mills and a commitment to ISO-certified quality, Gangsteel delivers S420NL plates tailored to your specifications. Stocked in various sizes and ready for immediate export worldwide. For detailed pricing and availability, visit our en 10025 3 s420nl normalized structural steel plate product page or contact our sales team today.

Summary

S420NL steel grade equivalent JIS is SM570, offering comparable yield strength (460 MPa vs. 420 MPa), tensile strength, and weldability. When normalized and impact-tested at -50°C, SM570 matches S420NL's low-temperature toughness for welded structures in extreme cold environments. S420NL from Gangsteel ensures durability in bridges, cranes, and offshore projects. Explore our range for customized solutions and competitive global supply.

FAQ

What is the JIS equivalent to S420NL steel grade?

SM570 (JIS G 3106) is the closest equivalent, with 460 MPa yield and similar weldability; specify normalization and -50°C impact testing for full equivalence.

How do S420NL and SM570 differ chemically?

S420NL has lower carbon (0.20% vs. 0.20%), phosphorus (0.025% vs. 0.035%), and sulfur (0.020% vs. 0.035%) for enhanced cold toughness, but both have comparable CEV (≤0.48) for weldability.

Are their mechanical properties identical?

SM570 has higher yield (460 MPa vs. 420 MPa) and tensile strength (570–720 MPa vs. 520–680 MPa) but similar elongation (19%). Impact at -50°C aligns if SM570 is normalized.

Can SM570 replace S420NL in cold environments?

Yes, if normalized and tested for 27 J at -50°C, SM570 matches S420NL's performance for applications like bridges or offshore platforms.

What if I need a higher-strength JIS equivalent?

For S460NL, consider SM570 with enhanced specs; contact Gangsteel for cross-standard guidance.