Welding pressure is one of the main parameters of the welding process, the two edges of the heating tube to the welding temperature, extrusion under pressure in a common that each crystal grain of the metal and the welding. Affects the size of the pressure welding the weld strength and toughness. If the welding pressure applied is small, the edge of the metal solder can not be sufficiently nip, the weld residual non-metallic inclusions and metallic oxides due to difficult to discharge pressure is small, the weld strength is reduced, by the force, easy to crack; excessive pressure When soldering temperatures reach most of extruded metal, not only reduces the weld strength, and produce internal and external burrs too large or lap welding defects. Therefore be based on the different varieties and specifications in practice the best obtained with suitable welding pressure. According to practical experience unit welding pressure is generally 20 ~ 40MPa. As tube width and thickness tolerances may exist, and the soldering temperature and velocity fluctuations are likely to involve changes in the pressing force to the weld. Welding is generally extruded by adjusting the distance between the pressing roller is controlled squeeze rolls can also be used before and after the control tube circumference difference.
Welding speed is one of the main parameters, which heating system, weld deformation speed, and mutual crystallization speed. In the high-frequency welded pipe, the weld quality welding speed with acceleration and improved. This is because the heating time can be shortened so that the edge heating zone width narrower, shorter time to form a metal oxide, if the welding speed is reduced, not only the heating zone widened, and the width of the melting zone with the heat input and change, forming the inner Glitch bigger. In low-speed welding, the welding heat input less difficult, if not meet the specified value is easy to produce defects. Therefore, high-frequency welded pipe, should be the unit of mechanical equipment and welding device the maximum allowed speed, depending on the specifications of varieties to choose suitable welding speed.
Squeeze roller aperture angle is the angle between the two edges of front tube, the size of the aperture angle on process stability and burnt, a great influence on the welding quality. Reducing the opening angle, the distance between the edges is also reduced, so that the proximity effect strengthened, the other conditions are the same edge of the heating temperature can be increased, thereby improving the welding speed. If the opening angle is too small, will rendezvous point to the centerline distance longer squeeze rolls, resulting in the highest temperature at the edge is not being squeezed, this will reduce the quality of the welding, the power consumption increases. Experience has shown that the actual production, the movable guide roller to adjust the longitudinal position of the size of the aperture angle. Longitudinal adjustment of the guide rollers is not the case, the thickness of the guide ring can be closed or the pressure hole to adjust the size of the aperture angle.
