High Frequency Welded Aluminum Tubes
- Profiles From 11mm to 52mm Height
- Multiple-chambered, Dimples and End-free Tube
- Metal Strip Gauges as thin as 0.25mm
Annual Production Capacity
Product | Code | Sectional Dimension Tolerance/(mm) | |||||
Height A | Crown B | End Diameter C | Corner Radius R | Out Diameter D | Thickness t | ||
Flat – Oval Aluminum Radiator Tube | R×× | ± 0.05 | ± 0.10 | ± 0.05 | ± 0.03 | – | ± 0.01 |
Flat – Oval Aluminum Oil Cooler Tube | O×× | ± 0.05 | ± 0.10 | ± 0.05 | – | ± 0.02 | |
Aluminum Charge Air Cooler Rectangular Tube | C×× | ± 0.05 | ± 0.25 | ± 0.05 | ± 0.05 | – | ± 0.02 |
Round Pipe for Condenser | P×× | – | – | – | – | ± 0.25 | ± 0.05 |
Length | Length Tolerance |
< 1000 | ± 0.5 |
≥ 1000 | ± 0.1 |
The full name is high frequency welded aluminum tube, abbreviated as HFW tube. Welded tube is made by using the skin effect and proximity effect of high frequency current to rapidly heat the edge of the pipe billet to the welding temperature for extrusion and welding.
In recent years, with the development of HFW welded pipe technology, its application area is expanding, except for the main use in HVAC&R and heat exchange, and it is increasingly used in the fields of oil pipe, boiler pipe and civil products, etc. Compared with seamless pipe, HFW welded pipe has a weld seam, and the performance of HFW welded pipe depends largely on the quality of the weld seam, so the quality of the weld seam becomes the most critical issue in the manufacturing process of HFW welded tube.
Aluminum Tube-stock alloy. Mother strip ofis the primary factor affecting the quality of the welding, the chemical composition of Aluminum tube alloy, segregation, inclusions, ribbon organization, sickle bend, plate edge burr can affect the quality of the weld seam.
The key to the forming process is to ensure that the welding into an "I" shape or a small "V" shaped butt, to avoid the V-shaped too large or inverted V-shaped butt (as shown in the figure). "I" shaped butt is the ideal form of welding, when the inner and outer walls of the aluminum tube contact at the same time, the temperature of the inner wall is higher than the temperature of the outer wall, V-shaped too large, resulting in the temperature difference between the inner and outer wall is too large, resulting in welding defects; inverted V-shaped butt because the outer wall of the aluminum tube first contact, will cause the slag can not be smoothly discharged, resulting in excessive slag in the weld.
High frequency welding process. The welding process of welding temperature, welding speed, extrusion amount, opening angle and other factors directly affect the quality of the weld.
Heat treatment process. Heat treatment is generally used online medium frequency weld heat treatment, heating temperature above the Ae3 line 50-100 degrees Celsius, can get fine grain ferrite + pearlite organization, thus improving the toughness.
The quality of HF Welded Aluminum tube is the result of multiple factors, and only through comprehensive and strict control of the above factors can the quality of the welded seam be guaranteed and high quality welded tube be produced.
