Working principle and influencing factors of resistance welding electrodes

Working principle and influencing factors of resistance welding electrodes

Resistance welding is a common metal welding method. Generally, the workpiece is placed under a certain electrode pressure and the resistance heat generated when the current passes through the workpiece is used to melt the contact surface between the two workpieces to realize the connection. A resistance welding electrode usually consists of two parts: a grip rod and a welding pole. The handle is the part connecting the electrode and the welding machine, and it is the channel for current conduction, while the welding electrode is the part that contacts the workpiece. The two parts need to have good electrical conductivity and heat transfer performance.

The resistance welding electrode is a part of the resistance welding equipment, which is mainly used to transmit electric energy and apply pressure. When performing resistance welding, the surface finish of the workpiece to be welded is of primary importance to obtain a stable welding quality. Therefore, the contact surface between the electrode and the workpiece and between the workpiece and the workpiece must be cleaned before welding. The design and manufacture of resistance welding electrodes need to consider factors such as material selection, structural design and surface treatment.

1. Material selection

Commonly used resistance welding electrode materials are copper, molybdenum and chromium copper. Copper is a metal with good conductivity and has good electrical conductivity and heat transfer performance, so it is a common electrode material. Molybdenum is a high temperature material with high melting point and oxidation resistance, suitable for high temperature welding. When selecting electrode materials, factors such as electrical conductivity, thermal conductivity, melting point, oxidation resistance, and mechanical strength need to be considered to meet welding needs.

2. Structural design

Structural design needs to consider factors such as the shape and size of the welding pole, the shape and size of the handle. The shape and size of the welding electrode depends on the shape and size of the workpiece, and it is necessary to ensure good contact with the workpiece during welding. The shape and size of the grip bar need to be designed according to the design and operating habits of the welding machine to facilitate operation and conduct current. In addition, factors such as the gap and pressure between the electrode and the workpiece need to be considered to ensure welding quality and efficiency.

3. Electrode surface treatment

The surface treatment of the resistance welding electrode can improve its electrical conductivity, heat transfer performance and oxidation resistance. The commonly used surface treatment methods are silver plating, gold plating, carburizing and so on. Silver plating and gold plating can improve the conductivity and oxidation resistance of the electrode, and protect the electrode from oxidation and corrosion. Carburizing can improve the hardness and wear resistance of the electrode and prolong the service life of the electrode. The surface treatment process also needs to control the treatment time and temperature to ensure the treatment effect.