Do you really understand acidic and basic welding electrodes?
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In the coating of welding electrodes, if it contains coating components primarily consisting of acidic oxides (such as titanium oxide and silica sand), such electrodes are called acidic welding electrodes; examples include ilmenite-type electrodes, titanic calcium-type electrodes, high-titanium-type electrodes, iron oxide-type electrodes, and cellulose-type electrodes； If the coating components mainly consist of basic oxides (such as calcium oxide), such electrodes are called basic electrodes; examples include low-hydrogen electrodes that contain carbonates and fluorite. Below is a comparison of acidic and basic welding electrodes:**Characteristics of acidic welding electrodes:**
1. The coating components have strong oxidizing properties.
2. They are less sensitive to pores caused by water or rust; the electrodes need to be baked at 75–150°C for 1 hour before use.
3. The arc is stable, allowing welding to be performed using either alternating current or direct current.
4. A higher welding current is required.
5. Long-arc welding is suitable.
6. The transfer of alloying elements is poor.
7. The weld shape is good, but the penetration depth is shallow.
8. The slag structure is glass-like.
9. Slag removal is easy.
10. The welds generally have average impact resistance at normal and low temperatures.
11. Their crack resistance is poor.
12. The hydrogen content in the welds is high, which can lead to the formation of “white spots” and affect plasticity.
**Characteristics of basic welding electrodes:**
1. The coating components have weak oxidizing properties.
2. They are more sensitive to pores caused by water or rust; the electrodes need to be baked at 350–400°C for 1–2 hours before use.
3. Due to the presence of fluorides in the coating, arc stability is compromised, so welding must be done using direct current. It can be used for both AC and DC power only when an arc-stabilizing agent is added to the flux. 4. The welding current is low, about 10% less than that of acidic welders of the same specification. 5. Short arc operation is recommended; otherwise, porosity is likely to occur. 6. The transfer of alloying elements is effective. 7. The weld shape is good, it is easy to build up thickness, and the penetration depth is slightly high. 8. The slag structure is crystalline. 9. Slag removal from the first layer within the groove is difficult, while slag removal from subsequent layers is easier. 10. The weld exhibits high impact resistance at normal and low temperatures