S355N vs S355JR Steel Comparison

S355N vs S355JR Steel Comparison

At Gangsteel, we’re here to clarify the differences between S355N vs S355JR, two high-strength structural steels under the EN 10025 standard, each tailored for specific structural applications. S355N, under EN 10025-3, is a normalized, low-alloy steel with 355 MPa yield strength and -20°C toughness, ideal for demanding structures like bridges and cranes in moderate climates. S355JR, under EN 10025-2, is a non-alloy, hot-rolled steel with similar strength but no guaranteed low-temperature toughness, suited for general construction.

As part of the en 10025 3 normalized steel plate and EN 10025-2 families, these grades serve distinct purposes. Gangsteel compares their chemical composition, mechanical properties, and applications, with ties 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.

Overview of S355N and S355JR

• S355N (EN 10025-3, 1.0545): A normalized or normalized rolled fine-grain steel with 355 MPa yield strength and -20°C toughness, designed for high-load applications requiring enhanced toughness, such as bridges and cranes in moderate climates.
• S355JR (EN 10025-2): A non-alloy, hot-rolled steel with 355 MPa yield strength, suited for general construction like buildings and infrastructure, with no mandatory low-temperature toughness testing.

S355N offers superior toughness due to its fine-grain structure and low-alloy composition, while S355JR is more cost-effective for less demanding applications.

Chemical Composition Comparison

The chemical composition of S355N vs S355JR influences their properties:

Carbon Equivalent (CEV):

• S355N: ≤0.43% (≤63 mm).
• S355JR: ≤0.45% (≤40 mm).

S355N’s microalloying (Nb, V, Al), lower carbon (0.20% vs 0.24%), and lower impurities (P: 0.030% vs 0.035%, S: 0.025% vs 0.035%) enhance its fine-grain structure and toughness, while S355JR’s simpler composition makes it more economical, similar to en 10025 3 s420n normalized structural steel plate.

Mechanical Properties Comparison

S355N vs S355JR 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 designs.
• Impact Toughness: S355N guarantees ≥27 J at -20°C; S355JR’s toughness is not mandatory but can be specified (e.g., as S355JR+AR with optional testing).
• Hardness: S355N’s slightly higher hardness (150-190 HB vs 140-180 HB) reflects its fine-grain structure.
• Thickness: S355N up to 200 mm, S355JR up to 400 mm, offering greater thickness versatility for S355JR, similar to en 10025 3 s355n normalized structural steel plate.

Processing and Fabrication

• S355N: Normalized for fine-grain microstructure, enhancing toughness for demanding welds. Preheating typically not required for <20 mm; optional for thicker plates (100-150°C); PWHT optional (550-650°C). CEV ≤0.43%.
• S355JR: Hot-rolled, non-alloy steel with simpler processing; excellent weldability due to low CEV (≤0.45%). Preheating rarely needed for thinner plates.

Consumables: Both use ER70S-6 (GMAW) and EM12K flux with EH14 wire (SAW). S355N’s lower impurities (S, P) and microalloying enhance weld quality, similar to en 10025 3 s275n normalized structural steel plate.

Applications

• S355N: Used in high-load structures like bridges, cranes, and heavy machinery in moderate climates, leveraging its guaranteed -20°C toughness and fine-grain structure.
• S355JR: Applied in general construction, buildings, and infrastructure where standard toughness is sufficient, benefiting from cost-effective processing.

S355N is preferred for critical applications requiring assured toughness, while S355JR suits cost-sensitive projects. For colder climates, consider en 10025 3 s355nl normalized structural steel plate.

Key Differences Summarized

Why Choose Gangsteel?

Gangsteel supplies S355N and S355JR:

• Inventory: Extensive stock in China.
• Sizes: Thickness 6–200 mm (S355N), up to 400 mm (S355JR), widths 2000/2500/3000 mm, lengths up to 12,000 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 en 10025 3 s355n normalized structural steel plate.

FAQ

What is the main difference in S355N vs S355JR?
S355N is a normalized, low-alloy steel with guaranteed -20°C toughness and microalloying, while S355JR is a non-alloy, hot-rolled steel with no mandatory toughness testing.

How do S355N and S355JR toughness compare?
S355N guarantees ≥27 J at -20°C, ideal for critical applications; S355JR’s toughness is not mandatory but can be specified.

Which is better for welding, S355N or S355JR?
S355N’s lower impurities (S: 0.025%, P: 0.030%) and CEV (≤0.43%) slightly enhance weldability compared to S355JR (S: 0.035%, P: 0.035%, CEV ≤0.45%).

What applications suit S355N vs S355JR?
S355N is ideal for high-load structures like bridges and cranes; S355JR suits general construction and buildings, similar to en 10025 3 s275n normalized structural steel plate.

How do S355N and S355JR costs compare?
S355N is 10-20% more expensive than S355JR due to normalization and microalloying.

What certifications support S355N and S355JR?
Gangsteel provides both with EN 10204 3.1/3.2, UT testing (EN 10160), and ABS/LR/BV/DNV approvals.

Summary

S355N and S355JR are high-strength structural steels under EN 10025, both offering 355 MPa yield strength and 470-630 MPa tensile strength, but differing in processing and toughness.

S355N (EN 10025-3) is a normalized, low-alloy steel with guaranteed -20°C toughness (≥27 J) for critical applications like bridges and cranes, while S355JR (EN 10025-2) is a non-alloy, hot-rolled steel for cost-effective general construction.

Gangsteel’s inventory supports thicknesses up to 200 mm (S355N) and 400 mm (S355JR), with global delivery in 7-30 days and certifications like EN 10204 3.1/3.2.

S355N excels in high-toughness applications, while S355JR offers versatility and lower costs, providing tailored solutions for diverse structural needs.