Table of Content
| Step | Parameters/Values |
|---|---|
| 1. Coil Preparation | Coil thickness: 1.0 - 10 mm |
| 2. Edge Milling | Trimmed edge width: 10-20 mm |
| 3. Forming | Roll forming temperature: 100 - 250°C |
| 4. Welding | Welding temperature: 1500 - 2000°C (localized heating) |
| 5. Weld Seam Smoothing | Seam thickness reduction: 2-3 mm |
| 6. Cooling | Cooling rate: 20 - 30°C per minute |
| 7. Sizing and Straightening | Straightening tolerance: ±1 mm |
| 8. Cutting | Length range: 6 m - 12 m per tube |
| 9. Testing and Quality Control | Hydrostatic pressure test: 10 - 50 MPa (depending on size) |
| 10. Finishing | Galvanizing temperature: 450 - 500°C |
| 11. Packaging and Dispatch | Packaging weight: Varies by size and order |
| Technique | Current Type | Temperature Range |
|---|---|---|
| High-Frequency Resistance Welding (HFRW) | High-Frequency AC | 1500°C - 2000°C |
| Low-Frequency Resistance Welding (LFRW) | Low-Frequency AC | 1200°C - 1500°C |
| Contact Welding | Direct Contact | 1200°C - 1800°C |
| Induction Welding | Electromagnetic Field | 1500°C - 1800°C |
| Flash Welding | High-Frequency AC | 1600°C - 2000°C |
| Direct Current (DC) Welding | Direct Current | 1500°C - 2000°C |
| Manufacturer | Location |
|---|---|
| SMS Group | Germany, Global |
| Nucor Tubular Products | USA |
| JFE Steel Corporation | Japan |
| Welded Tube Mill | China |
| JIULI Hi-Tech Metals | China |
| MSL | India |
| Yoder Manufacturing (Butech Bliss) | USA |
| OCTAL Steel | UAE |
| Stage | Temperature Range (°C) |
|---|---|
| Preheating | 200°C to 400°C |
| Welding Zone | 1,000°C to 1,300°C |
| Cooling | 300°C to 600°C |
| Post-weld Heat Treatment | 550°C to 700°C |
| Defect | Cause |
|---|---|
| Weld Defects | Incomplete weld, weld cracks, or porosity. |
| Ovality (Out-of-Round) | Improper roller settings, inconsistent material feed. |
| Wall Thickness Variation | Uneven material feed, improper roll alignment. |
| Surface Defects | Contamination, overheating, improper cooling. |
| Misalignment of Edges | Incorrect edge preparation, misalignment during welding. |
| Buckling or Distortion | Excessive heat or pressure, uneven cooling. |
| Internal Weld Bead | Excessive weld flash, too much pressure during welding. |
| Crimping or Flattening | Inadequate cooling, excessive pressure. |
| Dimensional Deviation | Inaccurate forming or cutting, fluctuating material feed. |
| Internal Contamination | Insufficient cleaning, low-quality material. |
