ZRS-, ZRSH-, ZR-, ZRH-configured ferrite cores of TDK (Japan) for a high-frequency tube welding.
Most significant electromagnetic parameters for a choice of cores for a high-frequency tube welding are an optimum combination of following parameters:
- Minimum losses at working frequency of welding generator (440 kHz)
- High value of Curie temperature
- High value of specific electric resistance
- High value of magnetic permeability
- High value of saturation magnetic flux density at a working temperature
A serious technological breakthrough in field of development of specialized ferrite materials for a high-frequency tube welding became IPH – material that is developed by TDK company (Japan) and that is today most advanced and innovative specialized ferrite material for this application field.
New material named IPH and issued by TDK permits to significantly decrease a level of energy saving due to a reduced value of generator’s anode current and to achieve higher work productivity due to an increase of line speed and to make higher a quality of welding seam.
Thanks to cooperation of LEPCOS Co. with USM Co. (Italy) which is an exclusive warehouse distributor of TDK within Europe on sale of ferrite cores for tube welding, these materials are made available for domestic producers of steel tubes.
Configurations and Standard Sizes of Ferrite Cores
Characteristics of IPH Material
|Initial magnetic permeability (μi)
(H = 0,24 A/m, f = 100 kHz, at 23°C)
|1800 ± 25%|
|Saturation magnetic flux density (Bs)
(H = 1194А/m at 23°C)
|≥ 490 mТ|
|Losses in rod (PCV)
f = 400 kHz, B = 200 mT, at 100°C)
|≤ 10000 kW/m³|
|Curie Temperature (Tc)||> 200°C|
|Density (d)||4,8 x 10³ kg/m³|
|Specific resistance (ρ)||3,0 Ohm • m|
Measurements were performed on ring cores.
Cores conform to requirements of directive RoHS. It signifies that lead, cadmium, mercury, hexavalent chrome and special antipyrenes based on brome (PBB and PBDE) are not used except for specially specified application versions according to EC-directive 2002/95/ЕС.
New brand of IPH possesses significantly lesser (according to results of our measurements - for 60%) magnetic resistance as compared with a majority of presently used foreign brands of other IP1 class manufacturers. It allowed to significantly reduce internal heat radiation weakening a saturation magnetic flux density and to increase an efficiency of welding process.
Dependency of losses in Impeder core on temperature.
Dependency of saturation magnetic flux density in Impeder core on temperature.