4 Reasons for Electrode Sticking During Welding

Adhesive electrode refers to the adhesion between electrode and parts caused by abnormal welding between electrode and parts during spot welding, which may lead to electrode being pulled out and parts rusting due to cooling water flow in severe cases.

There are four main reasons for electrode sticking during welding: the working surfaces of the two electrodes are not parallel, the working surfaces of the electrodes are rough, the electrode pressure is insufficient, and the water pipe at the cooling outlet of the welding gun is inversely connected or the cooling water circulation is blocked.

4 Reasons for Electrode Sticking During Welding 1

1. The working surfaces of two electrodes are not parallel

When the working surfaces of the two electrodes are not parallel, it will cause local contact between the working surfaces of the electrodes and the parts, increase the contact resistance between the electrodes and the parts, and decrease the current of the welding circuit.

Related reading: Wire Feeding Speed and Welding Current

When the current is concentrated at the local contact point, and the current density of the contact point is greater than the current density of the electrode working surface during normal welding, the temperature of the contact point will rise to the weldable temperature of the electrode and the part, which will form the fusion of the electrode and the part.

2. Rough electrode working surface

The working surface of the electrode cannot fully fit with the parts, and only some prominent parts contact the parts.

This situation will also cause the two electrode working surfaces to be out of parallel, causing electrode sticking.

4 Reasons for Electrode Sticking During Welding 2

3. Insufficient electrode pressure

The contact resistance is inversely proportional to the pressure.

Inadequate electrode pressure will increase the contact resistance between the electrode and the parts, and the resistance heat of the contact part will increase, making the temperature of the contact surface between the electrode and the parts rise to the weldable temperature, thus forming a fusion connection between the electrode and the parts.

4. The water pipe at the cooling outlet of the welding gun is inversely connected or the cooling water circulation is blocked

The water pipe at the cooling outlet of the welding gun is inversely connected or the cooling water circulation is blocked, and the electrode temperature rises, which may cause the fusion connection between the electrode and the parts during continuous spot welding.

The above four conditions are easy to lead to the fusion connection between the electrode and the parts, which leads to the phenomenon of electrode sticking.

So, how to avoid the phenomenon of electrode sticking?

4 Reasons for Electrode Sticking During Welding 3

(1) The electrode head shall be filed to make the working surfaces of the two electrodes parallel and free from rough defects.

The welding program can be selected as the grinding program (no current output), and the two electrode working surfaces can be observed whether they are parallel through an empty welding gun.

(2) In the grinding state, the welding shall be air punched for 5~10 times to forge the working face of the two electrodes, so as to increase the contact area within the specified electrode tip diameter range and improve the surface hardness.

(3) Heat the working surface of the electrode with oxyacetylene flame to form an oxide layer (oxide post) on the working surface of the electrode, which can improve the melting point of the working surface of the electrode and damage the weldability between the electrode and the parts.

(4) The working surface of the electrode shall be coated with red lead configured by the welder to destroy the weldability between the electrode and the parts.

(5) Adjust the electrode pressure, and use the welding parameters of high pressure, large power supply and short power on time.

(6) Clean the cooling water pipe regularly to ensure the cooling water flow.

The above measures can solve the problem of electrode sticking during welding.

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