In argon arc welding operations, the performance of tungsten electrodes is directly related to welding quality, efficiency and cost, and is one of the key factors that determine the success or failure of welding. Rare earth oxides doped in tungsten electrodes will significantly change their various properties, and thus have a multi-faceted impact on the welding process.
1. The importance of rare earth oxide doping to the performance of tungsten electrodes
Rare earth elements have become ideal doping materials for improving the performance of tungsten electrodes due to their unique electronic structure and chemical properties. After doping tungsten electrodes with rare earth oxides, key indicators such as their electron emission ability, anti-burning performance, and arc stability can be effectively improved. Different types of rare earth oxides have different directions and degrees of improvement in the performance of tungsten electrodes due to differences in atomic structure and chemical properties.
2. Common tungsten electrodes doped with rare earth oxides and their impact on argon arc welding
(I) Cerium tungsten electrode (CeO₂-W)
Cerium tungsten electrode is a widely used tungsten electrode, and its doped rare earth oxide is cerium oxide (CeO₂).
It performs well in arc stability. It can maintain a stable arc in a wide current range, and is not prone to arc drift and extinguishing even when welding at low current. This is especially important for thin plate welding, precision welding, and other scenes, and can reduce welding defects caused by arc instability.
It is easy and reliable to start the arc. Whether it is DC or AC argon arc welding, it can quickly establish a stable arc, greatly shortening the welding preparation time and improving welding efficiency.
During long-term welding, the electrode end wears slowly, which can extend the service life, reduce the frequency of electrode replacement, and reduce production costs. At the same time, its radioactivity is extremely low, and it is more in line with environmental protection and safety standards than thorium tungsten electrodes. It is highly favored in areas and industries with high environmental protection requirements.
(II) Lanthanum tungsten electrode (La₂O₃-W)
Lanthanum tungsten electrode uses lanthanum oxide (La₂O₃) as a dopant. It has high arc concentration and high energy density. It can make the weld penetration deeper and more uniform during welding. For thick plate welding or workpieces that require higher welding strength, it can ensure the mechanical properties of the weld.
Lanthanum tungsten electrode has a strong current-carrying capacity and can be used for welding operations with larger currents. It can still maintain stable performance under large currents and is not prone to overheating or burning. In addition, its recrystallization temperature is high. After high welding temperature, its microstructure and properties are not prone to significant changes. It can maintain good welding performance for a long time and has a long service life.
(III) Thorium tungsten electrode (ThO₂-W)
The thorium tungsten electrode was once widely used due to its good electron emission performance and arc stability. Its doped thorium oxide (ThO₂) can significantly improve the electron emission ability of the tungsten electrode. It can maintain a stable arc during high current welding and has a strong current carrying capacity, which is suitable for some heavy welding operations.
However, due to the radioactivity of thorium oxide, which poses potential hazards to human health and the environment, many countries and regions have imposed strict restrictions or prohibitions on its use. Special attention should be paid to relevant environmental protection and safety regulations when selecting it.
3. Selection Guide
Consider welding materials: When welding ferrous metals such as low-carbon steel and stainless steel, cerium tungsten electrodes and lanthanum tungsten electrodes are both good choices.
Focus on welding current: For small current precision welding, cerium tungsten electrodes are suitable to ensure arc stability; for large current heavy welding, lanthanum tungsten electrodes can be considered, or thoriated tungsten electrodes can be selected if they meet the regulations.
Attach importance to environmental protection and safety: In areas with high requirements for environmental protection and safety, thoriated tungsten electrodes should be avoided, and non-radioactive or low-radioactive electrodes such as cerium tungsten and lanthanum tungsten should be preferred.
Combined with cost factors: On the premise of meeting welding requirements, the price and service life of different tungsten electrodes can be comprehensively considered to select the most cost-effective product.
As a professional supplier of non-ferrous metal products, FANMETAL can provide customers with a variety of electrode products, not only the above-mentioned ones, but also molybdenum electrodes, tungsten copper electrodes, cobalt-based alloy electrodes, etc. If you have any questions about this product's details or delivery time, don't hesitate to get in touch with us at admin@fanmetalloy.com. We look forward to your message.
