the influences of pipe groove and impedance device for high frequency welding

The pipe slot is the section shape of the pipe slot.
The general manufacturer directly enters the high-frequency welding after cutting, and has the groove of \"I\" shape.
When the thickness of the welding material is greater than 8 ~ 10mm of the pipe, if this \"I\" groove is used, due to the curved arc, first of all, you need to melt the inner edge layer in contact with the tube blank to form a high internal Burr, it is easy to cause insufficient heat in the center layer and outer layer of the plate, affecting the high-frequency welding strength of the weld.
Therefore, in the production of thick wall pipes, it is best to make the groove into \"X\" shape through the process of chamfer or edge milling.
Practice has proved that in order to ensure the quality of the weld, this groove has a great relationship with uniform heating.
The selection of the groove shape also affects the adjustment of the meet angle size.
The design of welding joints is a weak loophole in welding engineering, mainly because the structural design of many steel structures is not completed by technicians.
For some groof with poor process performance, it\'s nothing new now.
The groove form plays a very important role in controlling the internal quality of the weld and the manufacturing quality of the welding structure.
The weld design must take into account the melting rate, welding space, welding position and comprehensive economic benefits of the weld metal.
The function of the impedance device is to strengthen the proximity effect of skin effect and high frequency current.
Impedance devices are usually composed of M-XO / N-
XO grade iron oxide system, usually made into 10 mm x (120-160)
Mm specification, encapsulated in heat-resistant and insulated housing, cooled internally with water.
The setting of the impedance device should match the diameter of the pipe to ensure the permeability of the impedance, in addition to the material requirements of the impedance, the corresponding flux should be ensured, at the same time to assurance impedance of transverse cross-sectional area and transverse cross-sectional area of
The cross-sectional area of the pipe diameter is large enough.
When manufacturing high
For example, in the production of API pipelines, burrs need to be removed.
The impedance device can only be placed inside the bayonet body, Cross
The section area of the impedance device will be much smaller accordingly, so the sector arrangement effect of the magnet concentration is better than the circular arrangement.
The distance between the impedance device and the position of the welding point will also affect the welding efficiency. The gap between the pipe wall and the impedance device generally needs 6 ~ 15mm, take a large diameter limit when the pipe is large.