Terms of Use - Contact Us - Make a Donation

Gas Tungsten-ArcWelding—GTAW

Gas tungsten-arc welding is basically a form of arc welding; however, in gas tungsten-arc welding, the elec-trode is used only to create the arc. The electrode is not consumed in the weld as in the shielded metal-arc process. The gas tungsten-arc welding process generally produces welds that are far superior to those produced by metallic arc welding electrodes. Especially useful for welding aluminum, it also may be used for welding many other types of metals. The GTA process is most effective for joining metals up to 1/8 inch thick, although you can use it to weld thicker material.

As shown in figure 8-2, the basic GTA process involves an intense arc between the base metal and a tungsten electrode. The arc, the electrode, and the weld zone are surrounded by an inert gas (usually either helium or argon or a mixture of the two) that displaces the air and eliminates the possibility of weld contami-nation by the oxygen and nitrogen present in the atmosphere. The tungsten electrode has a high melting point that makes it virtually nonconsumable.

• Specific advantages of gas tungsten-arc welding include the following:
• Welding can be done in all positions.
• The weld is usually equal to the base metal in composition.
• Flux is not used; therefore, finished welds do not require cleaning of corrosive residue.
• Smoke or fumes are not present to obscure vi-sion; therefore, you can easily see the welding process.
• Distortion of the base metal is minimal because the heat is concentrated in a small area.
• No splatter is produced because metal is not transferred across the arc.

Copyright © 2001-2006 SweetHaven Publishing Services
All rights reserved