Comparison of the characteristics of acidic and alkaline welding rods

Ⅰ. Definition of acidic welding rod and alkaline welding rod
Acidic welding rod and alkaline welding rod are two common welding materials, and their properties and application scenarios are different.

Acidic welding rod: The composition of the welding rod coating is mainly titanium oxide (such as rutile and titanium dioxide) and a considerable amount of calcium or magnesium carbonate ore, etc. This welding rod is called acidic (titanium type or titanium calcium) welding rod.

Alkaline welding rod: The welding rod coating contains a large amount of alkaline oxides, such as calcium monoxide, calcium carbonate ore, (marble or limestone) and fluorite, etc., and also contains alloy elements such as manganese, iron, ferrosilicon and ferrotitanium, etc. This welding rod is called alkaline welding rod.
In general, the process performance of acidic welding rod is better, but the mechanical properties of weld metal are poor; while the process performance of alkaline welding rod is slightly worse, but the mechanical properties of weld metal are better. Therefore, acidic welding rods are often used when welding general structural parts; alkaline welding rods are often used when welding important structural parts. Acidic welding rods are more economical than alkaline welding rods. Acidic welding rods should be used preferentially under the premise of meeting the performance requirements.

Ⅱ. Comparison of the characteristics of acidic and alkaline welding rods

Acidic welding rods
1. Not very sensitive to water and rust, baked at 100~150℃ for 1h before use
2. Stable arc, can be used for AC or DC welding
3. Large welding current
4. Long arc operation
5. Poor alloy element transition effect
6. Shallow penetration, better weld formation
7. Glassy slag, easy to remove slag
8. Normal and low temperature impact toughness of welds is average
9. Poor crack resistance of welds
lo. High hydrogen content in welds, affecting plasticity
11. Less smoke during welding

Alkaline welding rods
1. Highly sensitive to water and rust, baked at 300~350℃ for 1~2h before use
2. DC reverse connection welding is required: after adding arc stabilizer to the flux coating, AC and DC welding can be used
3. The same specification acid welding is about 10% smaller
4. Short arc operation is required, otherwise it is easy to cause pores
5. Good alloy element transition effect
6. Slightly deeper penetration, general weld formation
7. The slag is in the form of a product, and the slag removal is not as good as the acid electrode
8. The normal and low temperature impact toughness of the weld is higher
9. The weld has good crack resistance
10. The hydrogen content of the weld is low
11. Slightly more smoke during welding