Different tip angle of non-consumable tungsten electrode are used as per the application in GTAW process. Ever wondered what will be its effect on bead profile and penetration???
Electrode Tip angle varies from 15o to 180o. Narrow angle and Wider angle will effect on bead width, Arc starting, current carrying capacity, arc stability, weld penetration and electrode life.
Sharper Electrode (Narrow angle): Wider weld bead, Easier arc striking, less amperage, improved arc stability, less weld penetration, shorter electrode life.
Blunter Electrode (Wider angle): Narrower weld bead, harder arc striking, more amperage, increased potential for arc wander, better weld penetration, longer electrode life.
Proper Grinding technique:
The most important element of proper taper grinding is that the electrode must be ground longitudinally (lengthwise). Grinding electrode tips crosswise has a negative effect on the stability and formation of the arc at the electrode tip. Tungsten electrodes are manufactured with the molecular structure of the grain running lengthwise and thus grinding crosswise is “grinding against the grain.” More importantly, electrons flow at a greater density on the surface of the electrode. If electrodes are ground or polished crosswise the electrons have to jump across the grinding marks. The arc begins before the tip, spreads out, and usually wanders. The tungsten electrode becomes overheated and wears out quicker. By grinding longitudinally with the grain, the electrons are led steadily, with less difficulty to the extreme tip of the tungsten electrode. The arc starts straight and remains narrow, concentrated, and stable. The electrode is subjected to less thermal shock, and therefore lasts longer.
Keep reading, Happy welding…