S355J2G3 Steel Flange is a flange made from S355J2G3 steel, a non-alloy structural steel grade under the European standard EN 10025. This grade offers high tensile and yield strength, as well as excellent impact resistance, making it ideal for use in heavy-duty applications like construction, mechanical engineering, and pressure systems. S355J2G3 flanges are commonly used in industrial piping systems to connect pipes, valves, and other equipment, ensuring structural integrity under stress.

Key Features of S355J2G3 Steel Flange:

1. High Strength: S355J2G3 steel offers a minimum tensile strength of 450-680 MPa and a yield strength of 355 MPa, providing excellent durability and the ability to withstand high-pressure environments.

2. Impact Resistance: The material is characterized by its ability to withstand low-temperature impacts, with a Charpy V-notch test showing toughness at temperatures as low as -20°C. This makes it suitable for colder climates and applications.

3. Good Weldability: S355J2G3 steel has good weldability, which ensures reliable connections in piping and structural systems without the risk of cracking or failure at the weld joints.

4. Machinability: The steel grade can be easily machined, cut, and fabricated, allowing for customization into various flange types to suit specific industrial needs.

5. Corrosion Resistance: While S355J2G3 steel is not inherently corrosion-resistant like stainless steel, it can be treated with coatings to enhance its protection against corrosion in harsh environments.

Common Types of S355J2G3 Steel Flanges:

• Weld Neck Flange: Known for its strength and ability to handle high pressure, this flange is welded to the pipe, ensuring smooth flow and stress distribution.
• Slip-On Flange: Easier to install, slip-on flanges are slipped over the pipe and then welded in place, suitable for lower-pressure applications.
• Blind Flange: This type of flange is used to seal off a pipeline or system, providing easy access for future expansion or maintenance.
• Threaded Flange: Used in low-pressure systems, the threaded flange is screwed onto the pipe without the need for welding.
• Socket Weld Flange: Typically used in high-pressure, small-diameter applications, this flange allows for a strong and reliable welded connection.

Applications:

• Structural Engineering: S355J2G3 flanges are widely used in construction and structural engineering projects, connecting large components in bridges, buildings, and cranes.
• Industrial Piping Systems: These flanges are used to connect pipelines in industries such as oil and gas, petrochemicals, and water treatment.
• Mechanical Engineering: In the production of heavy machinery and equipment, S355J2G3 steel flanges are utilized for their strength and durability.
• Offshore Platforms: The excellent impact resistance of S355J2G3 steel makes it a good choice for offshore applications, where materials must endure harsh environments and heavy loads.
• Pressure Vessels: S355J2G3 flanges are often used in pressure vessel construction, helping to contain and manage high-pressure fluids safely.

Mechanical Properties:

• Tensile Strength: 450-680 MPa
• Yield Strength: 355 MPa minimum
• Impact Toughness: 27J at -20°C
• Elongation: 20%-22%, depending on thickness
• Hardness: Approximately 140-190 HB

Advantages:

• High Strength: The flanges made from S355J2G3 steel offer excellent structural integrity and can withstand significant pressure and mechanical stress.
• Cold Weather Performance: The impact resistance at low temperatures makes these flanges suitable for cold climates and outdoor installations.
• Durability: With high tensile and yield strength, S355J2G3 flanges provide long-lasting performance in both static and dynamic systems.
• Customizable: Available in a variety of sizes and configurations, S355J2G3 steel flanges can be customized to fit specific industrial applications.

Standards and Specifications:

• EN 10025: This is the European standard for non-alloy structural steels, governing the chemical composition and mechanical properties of S355J2G3 steel.
• ASME/ANSI B16.5: S355J2G3 steel flanges are typically manufactured according to these standards, ensuring compatibility with various piping systems.
• DIN: Many S355J2G3 flanges are also manufactured in accordance with German DIN standards.

Surface Treatment:

To enhance durability and performance, S355J2G3 steel flanges can undergo surface treatments such as:

• Galvanization: A zinc coating that provides protection against corrosion in harsh environments.
• Painting or Coating: Specialized paints or coatings can be applied to improve corrosion resistance, especially in applications where exposure to chemicals or moisture is common.
• Varnishing: A transparent protective layer that helps prevent rust and maintains the steel's appearance.

Sizes and Availability:

S355J2G3 steel flanges are available in a range of sizes, typically from ½ inch to 60 inches, with pressure ratings from 150# to 2500#. Custom dimensions can be provided based on project requirements, including thickness, bolt hole size, and face type (e.g., raised face, flat face).

Maintenance:

• Regular Inspection: Despite the strength of S355J2G3 flanges, it’s recommended to inspect them periodically for signs of wear, fatigue, or corrosion, particularly in high-pressure systems.
• Reapplication of Coatings: Protective surface coatings may need to be reapplied over time, depending on the environment and exposure to corrosive elements.

S355J2G3 Steel Flanges offer a high-strength, reliable solution for structural and piping applications where durability, impact resistance, and ease of fabrication are essential. Widely used in construction, oil and gas, and industrial systems, these flanges provide long-term performance under demanding conditions.