Difference Between Acid Electrode and Alkaline Electrode
Jul 21, 2021|
View:664According to the different properties of electrode coating, electrode can be divided into acid electrode and alkaline electrode.
（1） Electrodes containing a large amount of acid oxides (T102, Si02, etc.) in the coating are called acid electrodes.The acid electrode has the characteristics of good welding performance, easy arc ignition, stable arc, small splash, good fluidity of slag, easy slag removal and beautiful weld seam.Acid electrode can be used for both AC and DC.It is suitable for welding general low carbon steel and low alloy structural steel with low strength. It is the most widely used electrode.
（2） The coating containing a large amount of alkaline oxides (Ca0, Na20, etc.) is called alkaline electrode.Alkaline electrode has the characteristics of high plasticity and toughness and good cold crack resistance.It is generally required to use DC power supply and reverse welding method. Only when arc stabilizer is added to the coating can ac power supply be used for welding.It is mainly used for welding important structures (such as boiler, pressure vessel and alloy structural steel).Comparison of characteristics of acid electrode and alkaline electrode:
1.The coating components of acid electrode have strong oxidizability; However, the oxidizability of the coating components of alkaline electrode is weak.
2.The acid electrode has little sensitivity to water and rust, and the electrode is baked at 75-150 ℃ for 1H before use; The alkaline electrode is more sensitive to water and rust, and the electrode is baked at 350-400 ℃ for 1-2h before use.
3.The arc of acid electrode is stable and can be welded by AC or DC; The alkaline electrode, because the coating contains fluoride, deteriorates the arc stability, so DC welding must be used. AC and DC can be used only after adding arc stabilizer in the coating.
4.High welding current of acid electrode; The welding current of alkaline electrode is small, about 10% less than that of acid electrode of the same specification.
5.Acid electrode should be operated with long arc; The alkaline electrode should be operated in a short arc, otherwise it is easy to cause pores.
6.The transition effect of alloy elements in acid electrode is poor; The alkaline electrode has good alloy element transition effect.
7. Acid electrode has good weld formation and shallow penetration; The alkaline electrode has good weld formation, easy stacking and slightly deep penetration.
8.The slag structure of acid electrode is glassy; The slag structure of alkaline electrode is crystalline.
9.It is convenient for acid electrode to deslag; However, it is difficult to deslag the first layer in the groove of alkaline electrode, and it is easy to deslag the subsequent layers.
10.The weld of acid electrode is beautiful and the low-temperature impact performance is general; The alkaline electrode has poor weld and high low-temperature impact performance.
11.Acid electrode has poor crack resistance; The alkaline electrode has good crack resistance.
12.The hydrogen content in the weld of acid electrode is high, which is easy to produce "white spots" and affect the plasticity; The hydrogen content in alkaline electrode weld is low.
