Core Working Principle and Process Characteristics of Laser-Welded Finned Tubes

Core Working Principle and Process Characteristics of Laser-Welded Finned Tubes

The manufacturing core of laser-welded finned tubes lies in utilizing the high energy density of lasers (typically ≥10⁴ W/cm²) to achieve a metallurgical bond between fins and base tubes, rather than traditional brazing or expansion joining.

Process Flow

Pre-treatment: Surface rust and oil are removed from base tubes (typically steel or stainless steel tubes) and fins (steel or copper strips) to ensure clean welding surfaces.

Positioning and Assembly: Fins are spirally wound or longitudinally aligned onto the outer wall of the base tube. Fixtures secure their relative positions, maintaining a gap ≤0.1mm.

Laser Welding: The laser head traverses along the contact line between fins and base tube. The high-energy laser beam instantly melts the contacting metals, forming a continuous, dense weld seam (typically 0.5-2mm wide).

Post-Processing: Perform non-destructive testing (e.g., ultrasonic inspection) post-welding. Some products require surface passivation or coating to enhance corrosion resistance.

Core Process Advantages

Minimal Heat-Affected Zone: Concentrated laser heating creates a steep temperature gradient around the weld, limiting the HAZ width to 0.1-0.5mm. This prevents deformation or performance degradation in the base tube and fins due to high temperatures.

High weld quality: The metallurgical fusion weld achieves tensile strength exceeding 80% of the base tube material. It provides excellent sealing, withstands pressures above 10MPa, and eliminates the “crevice corrosion” risk associated with traditional expansion joints.

High efficiency: Welding speeds reach 1-5m/min, 3-5 times faster than conventional brazing, making it ideal for mass production.

Vrcoolertech CST offers customized laser-welded finned tubes tailored to customer drawings and specifications.