News & Technicals

Quality Control of Electric Resistance Welding Products

Although resistance spot welding is the most suitable welding method for mass production, improper quality management can cause huge losses. At present, since online non-destructive welding quality inspection cannot be realized, it is necessary to strengthen the management of quality assurance.

1. Pressure Inspection
The heat of welding is greatly affected by the contact resistance between the electrode and the workpiece. During the resistance welding process, the pressure must remain constant, so it is necessary to frequently use a pressure tester to weld

2. Electrode Polish
The increase in the number of welding will increase the wear of the electrode surface. The rough surface of the electrode will cause splashes and rough marks on the surface of the workpiece, which will affect the appearance of the workpiece. Therefore, it is necessary to prepare more ground electrodes and replace the electrodes appropriately according to the number of welding. Before using a new electrode, it is better to debug it as a waste workpiece.
3. Overheated Electrode
Overheating of the electrode will not only shorten the life of the electrode but also cause uneven welding quality of the workpiece.

4. Precise Workpiece
Welding defects often occur due to ignoring changes in workpiece thickness, plating thickness, metal composition, etc. Whether the quality of the workpiece itself is stable is also an important factor affecting welding quality.
5. Current Monitoring
Current monitoring is essential for welding. The main factors that affect the current change are: power supply voltage fluctuations, overheating caused by the overload of the welding machine, which reduces the current output, poor contact of the workpiece, and the current reduction, and the performance of the welding machine is poor.

In order to prevent poor welding results caused by the above reasons, it is necessary to monitor the welding current frequently. If the monitoring of welding current can be ensured, it is easier to find other causes of changes that affect welding quality, thereby further improving the reliability of welding quality.