s420nl steel grade properties

s420nl steel grade properties

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 S420NL Steel Grade?

S420NL steel grade, designated as 1.8912 under the European standard EN 10025-3, belongs to the family of weldable fine-grain steels. The "NL" suffix indicates its suitability for normalized delivery with a minimum impact energy of 27 Joules at -50°C in the longitudinal direction, making it perfect for cold climates and demanding environments. Compared to similar grades like en 10025 3 s420n normalized structural steel plate, S420NL offers improved low-temperature performance without compromising on strength.

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.

Mechanical Properties of S420NL Steel Grade

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.

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 properties highlight its exceptional strength (420 MPa yield), ductility (18–19% elongation), and low-temperature toughness (27 J at -50°C), making it a reliable choice for demanding welded structures. With a low-carbon composition (CEV ≤ 0.48) and fine-grain normalization, S420NL from Gangsteel excels in bridges, cranes, and offshore projects. Explore our range for customized solutions and competitive global supply.

FAQ

What is the difference between S420N and S420NL steel grade?

S420N provides impact testing down to -20°C (40 J longitudinal), while S420NL extends this to -50°C (27 J longitudinal). Both are normalized fine-grain steels under EN 10025-3, but S420NL is ideal for arctic or sub-zero conditions.

What are the maximum thicknesses available for S420NL plates?

Gangsteel supplies S420NL plates up to 250 mm thick, with mechanical properties adjusted for thicker sections to maintain structural integrity.

Is S420NL suitable for welding without preheating?

Yes, due to its low CEV (max 0.48), S420NL exhibits excellent weldability. Preheating is typically not required for thicknesses under 50 mm, but consult project specifications for optimal procedures.

What certifications does Gangsteel provide with S420NL plates?

All plates come with EN 10204 3.1 mill certificates, including chemical analysis, mechanical test results, and impact testing. We also offer third-party inspections like Lloyd's Register or DNV upon request.

Can S420NL be used in offshore structures?

Absolutely—its high toughness at -50°C and corrosion resistance (with proper coatings) make it a preferred material for offshore platforms, as per EN 10025-3 standards.