Spot welding forms a welded joint by applying high current for a short period of time in the welding area. It features high speed, high efficiency and a high degree of automation, and is suitable for welding thin – sheet materials and small workpieces.
Composition of spot welder
Spot welders are mainly composed of a welding power supply, welding tongs, a control system, and cables. The welding power supply provides the required current and voltage. The welding tongs are used to hold the workpieces and apply current. The control system is used to control the welding parameters and time. The cables connect all the components.
Preparation of welded joints
Before performing spot welding, it is necessary to prepare the joints to be welded. This includes cleaning the joint surfaces to remove grease, oxides, and other contaminants to ensure that the welding current can pass through the contact surfaces.
Selection of spot welding parameters
The key parameters in spot welding include welding current, time, and pressure. The selection of these parameters depends on the materials used and the thickness of the joint. Generally speaking, the magnitudes of the welding current and time should be determined according to the electrical conductivity, thermal conductivity, and thickness of the materials.
Control of the welding process
During the spot welding process, it is necessary to ensure the correct transmission and continuous application of current, the appropriate increase in temperature, and the tight bonding of the contact surfaces. The control system can monitor and adjust the parameters during the welding process through sensors and feedback mechanisms to ensure the welding quality.
Post-welding treatment
After welding is completed, post-treatment of the welded joints is required. This includes trimming the raised parts of the welding points, removing welding slag and oxides, and performing necessary surface treatments, such as grinding, polishing, or coating.
