Summary for S355JRH Steel Pipe
S355JRH is a non-alloy quality steel specifically designed for hollow structural sections (HSS) used in construction. The "H" indicates that the material properties are guaranteed for hollow sections. It is a high-strength, low-alloy steel known for its excellent weldability and toughness, especially in normalized or normalized-rolled conditions.
Breakdown of the Designation: S355JRH
The name tells you everything about the grade:
S: Stands for "Structural Steel".
355: Indicates the minimum yield strength of the material is 355 MPa (Megapascals) for thicknesses ≤ 16mm. The yield strength decreases slightly as the material thickness increases.
J: Denotes the impact energy (toughness) requirement. "J" means the steel must absorb 27 Joules at 0°C.
R: This means the product is supplied in a "Thermomechanically Rolled" condition.
H: This is the most important letter for pipes. It specifies that the steel is intended for "Hollow Sections".
Key Standard
This grade is defined by the European standard EN 10210-1:2006 and EN 10210-2:2006 for hot-finished structural hollow sections.
Mechanical Properties
The key mechanical properties as per EN 10210 are detailed in the table below. Note how the yield strength (ReH) changes with thickness.
| Property | Thickness (t) ≤ 16 mm | 16 mm < t ≤ 40 mm | 40 mm < t ≤ 63 mm | 63 mm < t ≤ 80 mm |
|---|---|---|---|---|
| Yield Strength (ReH), min | 355 MPa | 345 MPa | 335 MPa | 325 MPa |
| Tensile Strength (Rm) | 470 - 630 MPa | 470 - 630 MPa | 470 - 630 MPa | 450 - 610 MPa |
| Elongation (A), min | 22% | 22% | 22% | 22% |
| Impact Energy (KV) | 27 J at 0°C | 27 J at 0°C | 27 J at 0°C | 27 J at 0°C |
Chemical Composition (%)
The maximum percentages by weight are as follows. The specific composition is carefully controlled to achieve the desired mechanical properties and weldability.
| Element | C | Si | Mn | P | S | N |
|---|---|---|---|---|---|---|
| Max % | 0.20 | 0.55 | 1.60 | 0.030 | 0.030 | 0.015 |
Note: The CEV (Carbon Equivalent Value) is also specified to ensure good weldability. For S355JRH, the maximum CEV is typically 0.43% for sections up to 30mm thick.
Common Applications
S355JRH steel pipe is widely used in structural applications where high strength and good low-temperature toughness are required. Common uses include:
Building and Construction: Structural frames, columns, beams, and trusses.
Bridges: As part of the supporting structure.
Industrial Plants: Support structures for heavy machinery and platforms.
Architectural Structures: Exposed structural elements in modern architecture (e.g., canopies, railings, space frames).
Offshore and Marine: Certain non-primary structural components.
Agricultural and Material Handling Equipment.
Advantages of Using S355JRH Pipes
High Strength-to-Weight Ratio: Allows for lighter, more efficient structures compared to milder steels like S235.
Good Toughness: The "J" rating ensures it can withstand impact loads at low temperatures (down to 0°C), making it suitable for various climates.
Excellent Weldability: The controlled chemical composition and low Carbon Equivalent make it easy to weld without pre- or post-heating in most cases.
Aesthetic Appeal: Hollow sections offer a clean, modern look for architectural applications.
International Equivalents
It is important to note that equivalents are often similar, not identical. Always consult specific project specifications.
| Standard | Equivalent Grade | Note |
|---|---|---|
| ASTM A500 | Grade C | A500 Grade C is a common US equivalent, but the impact toughness requirements differ. |
| ISO 630-2 | S355J0H | The "0" indicates 27J at 0°C, making it functionally identical. |
| JIS G 3475 | STKT 540 | Japanese equivalent, with similar strength and application. |
| China GB/T 1591 | Q355B | The most common Chinese equivalent, though chemical and mechanical properties have minor differences. |
S355JRH vs. S355J2H
A closely related grade is S355J2H. The key difference is in the impact toughness:
S355JRH: 27 Joules at 0°C.
S355J2H: 27 Joules at -20°C.
Choose S355J2H for structures that will be exposed to colder winter climates.
Conclusion
S355JRH Carbon Steel Pipe is a premium, high-strength structural steel specifically engineered for use in hollow sections. Its combination of strength, toughness, and weldability makes it a first-choice material for modern construction and engineering projects across Europe and internationally.
