Polarity
Polarity in DC welding refers to the electrical connection of the electrodes, which determines heat distribution and thus penetration and deposition rate.
Physical-Chemical Mechanism of Action
In DC welding, polarity is the electrical polarity of the electrodes. The positive pole (anode) gives off electrons and heats up, while the negative pole (cathode) takes in electrons and heats less. This leads to an uneven heat distribution.
Metallurgical Relevance & Risks in Welding
Uneven polarity can lead to uneven distortion of the weld, porosity, and uneven material loss. This can affect the strength and toughness of the weld and cause cracks.
Workshop Practice & Action Guidelines
To ensure even heat distribution, position the electrodes so they are symmetric to the weld. Uneven polarity can be reduced by adjusting voltage or current. If you have heat distribution issues, check the pole positions and adjust them if needed.