Flux coating
Flux coating is a chemically tuned layer on stick electrodes that cleans the weld pool and protects it from contamination. It improves electrode life and weld quality.
Physico-chemical mechanism of action
The flux coating forms a thin, molten layer on the stick electrodes. This layer consists of the flux and the metal ions of the material being welded. It prevents direct contact between the electrode and the weld pool, which reduces chemical reactions and corrosion.
Metallurgical relevance & risks during welding
A missing or defective flux coating can lead to corrosion of the electrodes, which shortens their service life. This can lead to irregular melting and poorer weld metal. In addition, contamination of the weld pool by the electrode can lead to porosity and reduced mechanical properties of the weld.
Workshop practice & instructions
Make sure the flux is correctly matched and the electrodes are cleaned regularly. Monitor the service life of the electrodes and replace them at the first signs of corrosion or contamination. Keep the weld pool clean and check the chemical composition of the flux.