What is S355J2 steel?

Gangsteel, a leading manufacturer and exporter of structural steel plates, supplies premium EN 10025-2 S355J2 steel plates for construction, bridges, and heavy machinery applications. S355J2 is a non-alloy structural steel grade from EN 10025-2, offering high strength and low-temperature toughness at -20°C. This article provides a comprehensive overview of what S355J2 steel is, including its designation breakdown, chemical composition, mechanical properties, applications, and benefits, offering valuable insights for engineers, fabricators, and procurement specialists.

s355j2 steel Introduction to S355J2 Steel

S355J2 steel is part of the EN 10025-2 standard for hot-rolled non-alloy structural steels, specifying technical delivery conditions for products like plates, bars, and sections. It ensures consistent quality and performance for welded, bolted, and riveted structures. S355J2 is one of the most popular high-strength grades, known for its balance of strength and toughness in cold conditions.

The grade designation "S355J2" is a coded system:

• S: Stands for "Structural steel," indicating the steel is intended for structural purposes, such as load-bearing components in buildings or bridges.
• 355: Refers to the minimum yield strength in MPa for plates up to 16 mm thick. For thicker plates, the yield strength decreases slightly (e.g., 345 MPa for 16–40 mm).
• J2: Indicates the impact toughness, requiring a minimum Charpy V-notch impact energy of 27 J at -20°C. This ensures the steel resists brittle fracture in low temperatures.

This designation allows quick assessment of the steel's capabilities. For example, compared to EN 10025-2 S355JR steel (+20°C impact), S355J2 is better for cold environments. Gangsteel produces S355J2 plates in compliance with EN 10025-2, ensuring traceability and quality certification for global projects. For related grades, explore EN 10025-2 S355K2 steel or EN 10025-2 S450J0 steel.

s355j2 steel Chemical Composition

The chemical composition of s355j2 steel is optimized for strength, weldability, and toughness, with low carbon content to prevent brittleness. The table below shows the chemical composition limits (% by weight) as per EN 10025-2 for S355J2 (maximum values unless specified):

Key Notes on Chemical Composition:

• Carbon (C): Capped at 0.20% to ensure good weldability and ductility, reducing the risk of hardness in the heat-affected zone during welding.
• Manganese (Mn): Up to 1.60% enhances strength and toughness, crucial for load-bearing applications.
• Phosphorus (P) and Sulfur (S): Limited to 0.030% P and 0.025% S to improve impact resistance and reduce brittleness, especially important for the J2 toughness rating.
• Silicon (Si) and Copper (Cu): Provide moderate corrosion resistance, allowing the steel to form a protective patina in atmospheric exposure.
• Nitrogen (N): Controlled at 0.012% max to promote fine grain structure, improving mechanical performance.

This composition makes S355J2 a low-alloy steel with excellent formability. Gangsteel’s S355J2 plates are produced with precise chemical control, often with lower impurities for enhanced performance. For higher toughness, consider EN 10025-2 S355K2 steel.

s355j2 steel Mechanical Properties

S355J2 steel exhibits robust mechanical properties, suitable for structural engineering. The table below summarizes its key properties for plates up to 16 mm thick, as per EN 10025-2 (values decrease for thicker plates):

Key Notes on Mechanical Properties:

• Yield Strength: 355 MPa min allows for high-load applications, with values for thicker plates (e.g., 345 MPa for 16–40 mm).
• Tensile Strength: 470–630 MPa provides excellent resistance to breaking under tension.
• Elongation: 20% ensures good ductility for forming and welding.
• Impact Toughness: 27 J at -20°C guarantees resistance to brittle failure in cold conditions.
• Hardness: 150–200 HB indicates moderate hardness, easy to machine while durable.

These properties make S355J2 reliable for welded structures. For general use, consider EN 10025-2 S355JR steel from Gangsteel.

s355j2 steel Weldability and Fabrication

S355J2 steel has excellent weldability due to its low carbon equivalent (CEV max 0.45 for thicknesses up to 30 mm), allowing for welding without preheating in many cases. It is compatible with common welding methods like SMAW (using low-hydrogen electrodes such as E7018), GTAW, and SAW. For thicker plates (>40 mm), preheating to 100–150°C is recommended to avoid cracking in the heat-affected zone (HAZ).

Fabrication properties include good machinability and formability, with the normalized condition reducing distortion during heat treatment. Post-weld heat treatment (PWHT) at 600–650°C is advised for stress relief in ASME-coded applications. Gangsteel’s S355J2 plates are supplied with optimized bonding, ensuring reliable welding, similar to EN 10025-2 S235J2 steel but with higher strength

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s355j2 steel Physical Properties

Physical properties of S355J2 steel contribute to its usability in various environments:

• Density: 7.85 g/cm³, typical for carbon steels, ensuring predictable weight calculations in design.
• Thermal Conductivity: 50 W/m·K at room temperature, suitable for heat transfer in structural components.
• Coefficient of Thermal Expansion: 11–13 × 10^-6 /K, allowing for stable performance in temperature-varying conditions.
• Modulus of Elasticity: 210 GPa, providing stiffness for load-bearing structures.
• Poisson's Ratio: 0.3, indicating typical elastic behavior under stress.

These properties make S355J2 versatile for both static and dynamic loads, with good resistance to thermal expansion in construction. For offshore use, consider EN 10025-2 S355K2 steel.

s355j2 steel Corrosion Resistance and Durability

S355J2 steel has moderate corrosion resistance in non-aggressive environments, enhanced by silicon and copper additions that form a protective patina in atmospheric exposure. For corrosive conditions, it can be painted or galvanized. Its durability is evident in its fatigue resistance and toughness, with a fatigue limit around 150–200 MPa for cycles up to 10^7. In low-temperature applications, its -20°C impact toughness prevents brittle failure, extending service life in cold climates. Gangsteel offers clad or coated S355J2 plates for enhanced durability in harsh environments, such as EN 10025-2 S355JR+N.

Comparison with Other EN 10025-2 Grades

S355J2 steel is part of the S355 family, offering higher strength than S275 grades but similar toughness to S355K2 (40 J at -20°C). The table below compares S355J2 with other EN 10025-2 grades:

S355J2's -20°C toughness makes it superior to S355JR for cold applications. For higher strength, consider EN 10025-2 S450J0 steel.

Applications of S355J2 Steel

S355J2 steel is versatile and widely used in applications requiring high strength and good toughness:

1. Construction: For high-rise buildings, bridges, and stadiums, where its strength and ductility are essential.
2. Offshore Engineering: In platforms and wind turbines, leveraging its corrosion resistance and impact toughness.
3. Heavy Machinery: For cranes, excavators, and mining equipment, where durability under dynamic loads is critical.
4. Shipbuilding: In hulls and superstructures, benefiting from its weldability and strength.
5. Energy Sector: For pipelines and storage tanks, offering reliability in varying temperatures.

Gangsteel’s S355J2 plates are available in thicknesses from 6–300 mm, with options for cut-to-size and cladding for specialized applications like EN 10025-2 S355K2 steel.

Why Choose Gangsteel for S355J2 Steel?

Gangsteel is a trusted supplier of S355J2 and equivalent plates, offering:

• Certified Quality: Plates undergo ultrasonic testing, Charpy impact tests at -20°C, and chemical analysis to meet EN 10025-2 standards.
• Customization: Available in thicknesses from 6–300 mm, with options for normalization, cut-to-size, and beveling.
• Global Supply: Competitive pricing and reliable delivery from China to worldwide markets.
• Technical Support: Guidance on selecting S355J2 versus other grades like EN 10025-2 S355J0 or EN 10025-2 S355K2 steel.
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Gangsteel Solution

S355J2 is a non-alloy structural steel with 355 MPa yield strength, 470–630 MPa tensile, and 27 J impact at -20°C, ideal for construction and engineering. Gangsteel’s high-quality S355J2 plates ensure compliance and reliability for your projects. For equivalent standards, explore our BS EN 10025-2 material grade guide.

Gangsteel

Gangsteel explains S355J2 steel, detailing its designation, chemical composition, mechanical properties, and applications.Keywords: S355J2 steel, S355J2 properties, S355J2 chemical composition, S355J2 applications