High frequency pipe welding machine can improve the welding of thin-walled tubes and metal tubes through rapid development of welding, small welding heat affected zone, no need for cleaning and workpiece during welding.
The production technology of high-frequency pipe welding machine mainly depends on the diversity of products. A series of processes from raw materials to finished products are required. In order to complete these processes, various mechanical equipment and welding, electrical control and inspection devices are required. These equipment and devices are reasonably arranged according to different process requirements. Typical processes of high-frequency welded pipes are: longitudinal shearing - uncoiling - strip steel leveling - head and tail shearing - strip steel butt welding - looper storage - forming - welding - deburring - fixed length - flaw detection - flying shear - initial inspection - steel pipe straightening - pipe section processing - hydrostatic test - crack detection - printing coating - finished products.
When the high-frequency welding machine determines the oscillator, inductance and impedance, the efficiency of the oscillation box, output transformer and inductance will be determined. The change of input power is roughly proportional to the change of input heat. If the input heat is insufficient, the heating edge cannot reach the welding temperature, and the solid structure is kept without welding, forming welding cracks; If the input heat is large, the heating edge is easy to overheat when it exceeds the welding temperature. Even if it is overheated, cracks will appear after stress; When the input heat is too high, the welding temperature is too high, which will lead to weld cracking, resulting in molten metal splashing and forming holes. The welding temperature is generally 1350~1400 ℃.
The welding pressure of high-frequency pipe welding machine is one of the main parameters in the welding process. After both sides of the pipe are heated to the welding temperature, common metal grains are formed under the action of extrusion force, namely mutual crystallization welding. Welding pressure affects the strength and toughness of the weld. If the applied welding pressure is small, the welding edge of the metal cannot be fully compressed, the residual non-metallic inclusions and metal oxides in the weld are not easy to discharge due to the low pressure, the strength of the weld decreases, and the weld is easy to crack after being stressed; When the pressure is too high, most of the metal that reaches the welding temperature is extruded, which not only reduces the welding strength, but also produces excessive internal and external burrs or lap welding and other defects. Therefore, in practical application, reasonable welding pressure should be obtained according to different varieties and specifications. According to practical experience, the unit welding pressure is generally 20~40mpa.
Due to the possible tolerances of tube blank width and thickness, as well as the fluctuation of increasing welding temperature and welding development speed, the changes of different welding extrusion forces may not be involved. The welding extrusion amount can usually be controlled by constantly adjusting the distance between the enterprise extrusion rolls or controlling the perimeter difference between the front and rear tubes of the extrusion roll.
