EN10219 Cold Formed Structural Hollow Sections - Clarification on Welding Process
EN10219 primarily covers cold-formed structural hollow sections.primary welding process specified in the standard is High-Frequency Welding (HFW).
of EN10219, especially for thicker walls or specific project specifications. In this context, it is a "cold-formed, LSAW pipe to EN10219."
1. Standard Scope: EN10219-1 & EN10219-2
Part 1: EN10219-1: Technical delivery conditions.
Part 2: EN10219-2:cold-formed welded steel.
Key Manufacturing Difference from EN10210:
EN10210: Hot-finished (formed and possibly welded at high temperature, often normalized).
EN10219: Cold-formed (formed at ambient temperature from strip or plate, then welded). This affects tolerances, residual stresses, and available sizes.
2. Steel Grades & Mechanical Properties
The standard defines steel grades based on minimum yield strength and impact toughness. The grades are similar but not identical to EN10210.
Table 1: Common Steel Grades and Mechanical Properties (EN10219-1)
| S235JRH | 235 | 360 - 510 | 21 | 27 J at +20℃ | |
| S275J0H | 275 | 410 - 560 | 20 | 27 J at 0℃ | |
| S275J2H | 275 | 410 - 560 | 20 | 27 J at -20℃ | |
| S355J0H | 355 | 470 - 630 | 20 | 27 J at 0℃ | |
| S355J2H | 355 | 470 - 630 | 20 | 27 J at -20℃ | |
| S355K2H | 355 | 470 - 630 | 20 | 40 J at -20℃ | |
| S460NH/NLH* | 460 | 550 - 720 | 17 | 40 J at -20℃ / -50℃ | Often LSAW+Normalized |
J0, J2, K2: Designate impact energy and test temperature (+20℃, 0℃, -20℃).
H: Denotes "Hollow Section".
*Grades like S460NH/NLH: To achieve these higher strengths with good toughness after cold-forming, the manufacturing route often involves using a normalized plate, forming, and then using for the longitudinal seam, followed by potential post-weld heat treatment. This is where LSAW fits into the EN10219 scope.
3. Dimensions & Tolerances for Circular Hollow Sections (CHS)
Cold-forming allows for tighter dimensional tolerances compared to hot-finished products.
Table 2: Size Range and Tolerances for Cold-Formed CHS (Extract)
| Tolerance on Diameter (at any cross-section) | |||
|---|---|---|---|
| 21.3 - 168.3 | 1.0 - 8.0 | ± 0.5 mm (D <= 40mm) to ± 0.75% of D | Typically ± 10% of nominal 't' |
| > 168.3 - 457 | 2.0 - 12.5 | ± 0.75% of D | Typically ± 10% of nominal 't' |
| > 457 - 1200* | 4.0 - 16.0+ | ± 0.75% of D or as agreed | Typically ± 10% or as agreed |
*Note: Sizes above ~457mm are less common for classic cold-forming and may involve a hybrid LSAW approach.*
4. Manufacturing Route for an "EN10219 LSAW Pipe"
Cold-formed from normalized steel plate (e.g., EN10025 S460NL).
Plate is cold-formed (e.g., via a UOE process) into a cylinder.
for superior weld quality and penetration on thick material.
Post-Weld Treatment: The weld area may be normalized or the entire pipe stress-relieved to restore properties.
It is then tested and inspected as per EN10219-1 requirements.
5. Key Comparison: EN10210 LSAW vs. EN10219 LSAW
| EN10210 (Typical LSAW) | EN10219 (Cold-Formed + possible LSAW) | |
|---|---|---|
| Hot-finished, Normalized | Cold-formed | |
| High-Frequency Welding (HFW) | ||
| Lower (due to hot-finish/normalizing) | Higher (due to cold-forming) | |
| S355J2H, S355NH | S355J2H, S355K2H, S460NH |
EN10219 is fundamentally a standard for cold-formed welded hollow sections
Higher strength grades (S460 and above).
Applications requiring verified weld integrity on thicker walls.
Projects specifying cold-formed tolerances but SAW weld quality.
"LSAW Pipe manufactured to EN10219" which combines the dimensional precision of cold-forming with the robust weld quality of the submerged arc process.
