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Electric Current through a TIG Welder

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Althouse, Andrew, William & Kevin Bowditch, and Carl Turnquist. Modern Welding. Tinley Park, IL: Goodheart-Willcox, 1997. 343-345. "the amount of current must be selected. Figures 14-19 through 14-23 are tables that list current ranges… Fig. 14-19. Amperage 60-210. Fig. 14-20 Amperage 60-320.Fig. 14-21 Amperage 40-180. Fig. 14-22 Amperage 60-370. Fig. 14-23 Amperage110-700." 40-700 A
Lincoln Electric.The Procedure Handbook of Arc Welding. Thirteenth Edition: Lincoln Electric, 1994.
Direct Current A Alternating Current A
- polarity + polarity Unbalanced Wave Balanced Wave
5-1000 10-125 5-450 5-630 10-630 10-400 5-525 10-525
5-1000 A
Hoppes, Matt. Selecting a GTAW Power source. Practical Welding Today. 10 January 2002. "For a example, a machine with a duty cycle rating of 150 amps at 60 percent duty cycle means that the machine can produce 150 amps for six minutes and then must cool for four minutes. A machine with a rating of 300 amps at 100 percent duty cycle means that the machine can produce 300 amps of current continuously." 150- 300 A
Cary, Howard B. Modern Welding Technology. Fourth Edition: Englewood Cliffs, NJ: Prentice Hall, 1979. 76. "A typical GTAW welding machine operates with a range of 3 to 200 A or 5 to 300 A with a range of 10 to 35 V at 60 percent duty cycle." 3 to 200 A
TIG Welders -Square wave, etc. Daytona MIG. "Output range 1-130 A, infinite control 140 A peak." 10-140 A

Tungsten inert gas (TIG) welding, also known as gas tungsten arc welding (GTAW) is a process were joining of two metals occur. Heat from an electric arc formed between a tungsten electrode and the metal being worked on melts the ends of the metal and the probe so welding may occur. A chemically inert gas or a mixture of inert gases, such as argon, helium or hydrogen, is used to shield the metal from oxidation.

Different factors are taken into consideration when selecting the amount of current that will be used, thus the quantity of electric current that flows through a TIG welder varies. The type and thickness of the metal to be welded determines the amount and type of current, which in turn determines the type of shield gas to be used. Direct current (DC) with the electrode negative offers deep penetration and fast welding speed, with helium gas used as a shield resulting in a large amount of current being used. Direct current with a positive electrode offers less penetration but removes surface oxides from metals resulting in lower amounts of current being used. Alternating current (AC) removes oxides from metal surfaces with a sputtering motion allowing for excellent welds resulting in a moderate amount of current being used. Argon though must be used as the shielding gas with AC instead of helium because helium doesn't sputter. Argon is the most commonly used shielding gas regardless of direct or alternating current.

The electrode diameter as well as its composition of tungsten will affect the amount and type of current flowing through the TIG welder. Electrodes small in diameter with a majority of its composition made from tungsten may carry only small amounts of current regardless of its polarity. Electrodes large in diameter despite composition and polarity will carry large amounts of current through the welder.

Manufacturers make products such as automobiles, home appliances, and furniture by using TIG welding. Construction companies use welding techniques to build various structures such as bridges and edifices. The amount of current varies with numerous factors. This results in a large variation of electric current flowing through a TIG welder. The range of current starts as low as 5 A and goes as high as 1000A.

Jola Lewinski -- 2003