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Why electrode sticks to galvanized sheet when welding? [DCS15]

Jan 02,2024

Why does the electrode stick to the galvanized sheet when welded by intermediate frequency welder? The reason comes to the electrode materials which are mostly chrome copper or chrome zirconium copper.

In high temperature welding, the copper in the electrode material reacts with the zinc in the galvanized sheet to form an alloy of copper and zinc, which happens to be the brass alloy component. The chemical reaction of the copper-zinc alloy looks like an electrode sticking to a galvanized sheet.

How to avoid this adhesion phenomenon?

1. The best solution is to use aluminum oxide copper. Aluminum oxide copper is an excellent electrode material for resistance welding. Its softening temperature is up to 900 °C. It has the characteristics of high strength, good electrical conductivity and wear resistance, long service life, and will not cause adhesion phenomenon between electrode and workpiece.

2.If the electrode materials are chromium-copper and chromium-zirconium-copper, two discharges are required during welding. Two current outputs should be set up to the intermediate frequency welding machine. The first current (smaller) will break down the coating initially. Next, the second current will weld the workpiece up. This way the workpiece will be firmly welded and electrode adhesion phenomenon will be improved greatly.