What Is a Seam Welder?

Seam welding machine refers to a resistance welding machine where the weldment is assembled into an overlap or butt joint and placed between two roller electrodes. The roller electrode pressurizes the weldment and rotates, continuously or intermittently pulsed power to form a continuous weld . It can also be said that the seam welding machine is an evolution of spot welding. Seam welding is widely used in the manufacture of joints that require tightness. Sometimes it is also used to weld ordinary non-hermetic sheet metal parts. The thickness of the metal material to be welded is usually 0.1 ~ 2.5mm.

The seam welding machine is a resistance welding machine in which the workpiece is placed between the roller electrodes or between the roller electrodes and the strip electrodes, and is continuously or intermittently rolled, and the current is intermittently or continuously applied to form a linear weld.

The seam welding machine can be divided into continuous seam welding machine and step seam welding machine according to the rotation mode of the roller electrode. According to the relationship between the welding seam and the electrode arm, it can be divided into horizontal seam welding machine, longitudinal seam welding machine and universal seam welding. machine.

1.Transverse seam welding machine

The weld formed is perpendicular to the electrode arm. The rotating axis of the roller electrode of this type of welding machine is parallel to the electrode arm, as shown in the figure below. It is mainly used to weld long welding seams of horizontal workpieces and circumferential annular welding seams.

1) Seam welding is the same as spot welding, which is a thermal-mechanical (force) combined welding process. In comparison, the mechanical (force) effect is insufficient during the welding process (except step seam welding), and the faster the welding speed, the more obvious the performance.

2) The seam welding seam is composed of welding points that overlap each other, so the shunt during welding is more serious than that of spot welding, which makes it difficult to weld thick plates of aluminum alloys and magnesium alloys with high conductivity.

3) The surface of the roller electrode is prone to sticky damage and the quality of the weld surface is deteriorated. Therefore, the trimming of the electrode is a particularly noteworthy issue.

4) Because the cross-sectional area of the seam weld is usually more than twice the longitudinal load area of the base metal (the thinner the plate, the larger the ratio), the damage must occur in the heat affected zone of the base metal. Therefore, the joint strength is rarely emphasized on the seam welded structure, and it is mainly required to have good sealing and corrosion resistance.

Seam welding machines are widely used for welding thin plates in oil tanks, cans, radiators, aircraft and automobile fuel tanks, and sealed containers in jet engines, rockets and missiles.