Technical Specification: EN10219-1 S275JOH Spiral Submerged Arc Welded Pipe
This document details the standard, material, manufacturing process, and key properties of this specific grade of structural steel pipe.
1. Governing Standard: EN 10219-1
Full Title: *Cold formed welded structural hollow sections of non-alloy and fine grain steels - Part 1: Technical delivery conditions.*
Scope: This European standard specifies the technical delivery requirements for cold-formed welded circular, square, and rectangular hollow sections intended for use in load-bearing steel structures.
Key Focus: Ensures dimensional tolerances, mechanical properties, weld quality, and inspection procedures for structural integrity.
2. Material Grade: S275JOH
This designation follows the EN 10025-2 standard for hot-rolled structural steels. The breakdown is as follows:
| Letter/Number | Meaning | Specification |
|---|---|---|
| S | Structural Steel | Denotes steel intended for construction purposes. |
| 275 | Minimum Yield Strength | The minimum yield strength (ReH) is 275 MPa (Megapascals). This is higher than the common S235 grade. |
| J | Impact Toughness | The material is guaranteed to meet a specified Charpy V-notch impact energy at a defined temperature. |
| O | Impact Test Temperature | Specifically, the impact test is conducted at 0°C. |
| H | Hollow Sections | Indicates the steel is supplied and certified for the manufacture of hollow sections (tubes/pipes). |
Key Material Properties Summary:
Higher Strength: The 275 MPa minimum yield strength provides approximately 17% higher load-bearing capacity compared to S235 grade, allowing for lighter or stronger structures.
Good Low-Temperature Toughness: Guaranteed impact toughness at 0°C makes it suitable for structures in temperate climates or with dynamic loading considerations.
Excellent Weldability: The fine grain structure and controlled chemical composition ensure good weldability without pre-heating in most standard thicknesses.
3. Manufacturing Process: Spiral Submerged Arc Welding (SSAW)
This describes the specific pipe-forming and welding method.
| Aspect | Description |
|---|---|
| Forming Method | Hot-rolled steel coil (strip) is continuously cold-formed at a precise angle into a helical (spiral) shape. |
| Welding Method | Submerged Arc Welding (SAW): The weld arc is submerged under a layer of granular flux. This allows for deep penetration, high deposition rates, and excellent weld quality with a smooth finish. |
| Key Advantages | 1. Can produce large diameters from narrower strips. 2. Cost-effective for medium to large diameters. 3. Continuous production process. |
| Typical Applications | Structural columns, piling pipes, wind turbine towers, water transmission pipelines, industrial support structures. |
4. Key Comparative Data (Typical Values)
The table below compares S275JOH with the more common S235JRH grade within the EN 10219-1 framework.
| Property / Characteristic | S275JOH (This Grade) | S235JRH (Reference Grade) |
|---|---|---|
| Minimum Yield Strength (ReH) | 275 MPa | 235 MPa |
| Typical Tensile Strength (Rm) | 410 - 560 MPa | 360 - 510 MPa |
| Impact Test Temperature | 0°C | 0°C |
| Relative Structural Efficiency | Higher - Allows for weight savings or increased load capacity. | Standard - Good general-purpose strength. |
| Common Application Focus | Structures requiring higher strength-to-weight ratio, such as taller columns, longer spans, or heavier dynamic loads. | General building frames, supports, and structures where standard strength is sufficient. |
| Chemical Composition (Max % - typical) | Lower Carbon (C) content than older S275 grades, improving weldability. | Slightly higher permissible C content. |
5. Summary
An EN10219-1 S275JOH Spiral Submerged Arc Welded Pipe is a high-strength structural hollow section characterized by:
Standard Compliance: Manufactured to the European standard for cold-formed structural tubes.
Superior Material: Made from S275JOH steel, offering a minimum yield strength of 275 MPa and verified impact toughness at 0°C.
Robust Construction: Produced via the reliable and efficient SSAW process, suitable for demanding structural applications.
Primary Use: Ideal for engineered steel structures where increased strength (compared to S235) leads to material savings, larger spans, or enhanced safety factors.
