High-frequency welding equipment is used to achieve high-frequency welding electrical mechanical systems, high-frequency welding equipment is composed of high-frequency welding machine and pipe machine thereof. Which generally consists of high-frequency welding machine high frequency generator and the feeding device composed of two parts, its role is to generate a high frequency current and control it; extrusion molding machine by a roller frame composition, its role is to be a high frequency current partially fused to squeeze, excluding the oxide layer and the steel sheet surface impurities, the steel sheet completely fused together.
Many factors affect the quality of high-frequency welding, and the interaction of these factors in the same system, a factor that has changed, other factors also as it is changed. Therefore, when the high-frequency adjustment, just noted that local regulation of frequencies, and other current or pressing amount is not enough, this adjustment must be based on the specific conditions of the entire molding system from all aspects associated with the high-frequency welding to adjustment.
The frequency of high-frequency welding have a great impact on the welding, because high frequency currents affect the internal distribution of steel. Selection of high and low frequency welding impact is mainly the size of the weld heat affected zone. From the welding efficiency, it should be possible to use higher frequencies. 100KHz frequency current can penetrate ferritic steel 0.1mm, 400KHz can only penetrate 0.04mm, that is, the current density distribution of the steel surface, which is nearly 2.5 times higher than the former. In the production practice, carbon steel welding material is generally selected frequency of 350KHz ~ 450KHz; alloy welding materials, welding more than 10mm thick steel plate, can be used as 50KHz ~ 150KHz low frequency, as contained in the alloy skin effect and chrome steel, zinc, copper, aluminum and other elements there are some differences. After the high-frequency foreign equipment manufacturers are now mostly used the new technology of solid-state high-frequency, it is set in a frequency range, automatic tracking during welding adjust the frequency depending on the material thickness, line speed and so on.
Enter the high-frequency welding power control is very important. Too small power tube groove insufficient heating, reach soldering temperatures will cause weld, desoldering, weld and other folders not weld defects; power is too large, the impact on the stability of the welding, surface heating tube groove soldering temperature is much higher than the desired temperature, causing serious splash, pinholes, slag and other defects, such defects is called burnt defects. Input power high-frequency welding according to wall thickness and molding speed adjustment determination, forming different way, different unit equipment, different material grade, all we need to sum up the first production line, preparing for their own unit equipment high-frequency technology.
High-frequency welding originated in the 1950's, it is the use of skin effect and the effect of the adjacent high-frequency current generated by the steel and other metal materials docking of new welding processes. And the emergence of high-frequency welding technology is mature, directly contributed to the development of longitudinal huge industry, it is the key step of erw steel pipe produced. High-frequency welding quality has a direct impact on the overall strength of welded pipe products, quality levels and production rates.