Tungsten electrodes are preferred in welding because they create excellent fusion in arc welding processes such as GTAW (Gas Tungsten Arc Welding) or PAW (Plasma Arc Welding). However, the same electrode can cause inclusions that present an issue during high-spec weld applications. To reduce the tungsten inclusion during GTAW, welders can control the current and gas flow rate. However, the other most effective method is sharpening and polishing tungsten electrodes. In this article, we will discuss how sharpening tungsten electrodes can result in high-quality fusion.
Tungsten Entrapment During Welding
One of the common problems in welding is the entrapment of inclusions such as slag, oxides, or tungsten. When the tungsten electrode is used during GTAW or PAW, its particles can separate and corrupt the weld pool. This can happen when:
- The tungsten electrode touches the molten puddle
- The tungsten electrode comes in contact with the filler metal
- The current used is more than the maximum limit of the tungsten electrode resulting in the melting of the electrode
- There is a crack in the electrode resulting in the split of the particles into the weld pool.
Regardless of the reason, the inclusion of tungsten in the weld pool creates discontinuities and results in weak joint formation. There are several options to help welders prevent tungsten inclusions. Welders can ensure that the electrode is in good condition, optimize the current requirement, and keep the electrode at a distance during welding. In addition to this, one of the most important preventative measures is sharpening tungsten electrodes.
How Does Sharpening Tungsten Electrodes Help?
Electrode geometry, including diameter and angle, are important considerations during arc welding preparations. Different angles produce a variety of weld results. While blunt electrodes can handle high amperages and create deeper penetration, sharp electrodes provide a more consistent arc. Using an incorrect electrode angle for the given amperage can reduce electrode life while increasing the likelihood of tungsten inclusion in the weld pool.
Welders can prevent tungsten inclusion by sharpening and polishing the electrode to achieve the desired angle. This can be achieved for tungsten electrodes with the help of bench or angle grinders, belt or disc sharpeners, and chemical sharpeners. The smoothly ground and polished tungsten electrode results in:
- Smooth electrode surface without burrs to deteriorate electrodes and introduce contamination in the weld pool
- Arc stability and desired weld penetration with appropriate grind angle.
However, care is required when sharpening the electrode. Note the following recommendations:
- Check if the sharpening is at the correct angle
- Ensure there are no broken tips
- Make sure to flatten the tip when it is sharpened
- Refrain from using manual methods for sharpening
- Make sure the grinder is clean.
Welders can achieve the smoothest tungsten electrodes by leveraging CNC machining for sharpening and polishing.
Ensuring High-Quality Weld for GTAW
Sharpening tungsten electrodes is not a complicated task, but it does require careful consideration. This involves not only electrode preparation and examination but also the welding process. For instance, when performing orbital GTAW, a sharp grind angle is preferable. With the control offered by orbital welding, a sharp electrode can achieve deeper penetration without risking deteriorating the tungsten electrode—even when the amperage is low.
By sharpening tungsten electrodes and using the appropriate tools and methods, smoothly polished tungsten electrodes can enable high-quality weld results.
Arc Machines, Inc., a leading provider of orbital welding solutions, provides high-quality sharpened tungsten electrodes to support your high-specification welding applications. For inquiries regarding products, contact sales@arcmachines.com. For service inquiries, contact service@arcmachines.com. Arc Machines welcomes the opportunity to discuss your specific needs. Contact us to arrange a meeting.
