11.5 Chapter Conclusion
Karl Fulton
Summary
GTAW is an arc welding process utilizing a non-consumable tungsten electrode and inert shielding gas to protect molten puddles. GTAW gives welders a very high degree of control over the molten puddle. This process is used widely in industries such as food processing equipment, casting repair, aerospace, spacecraft, and more.
The weld machine can have a wide variety of settings to help with puddle manipulation, arc shape, and even cleaning. The type of shielding gas used—argon, helium, or a mixture—affects the penetration of the weld. There are many alloys of tungsten, so the type of tungsten used can be a personal preference for each welder.
Also, cleanliness and fit up are incredibly important factors in GTAW and should not be taken lightly.
Review Questions
- What was GTAW originally developed for?
- What do you do if it starts to hurt as you are welding?
- Stop
- Suck it up
- Grit your teeth
- Make funny noises until you are done
- What is the safety concern about using a thoriated tungsten?
- What percentage of heat is on the tungsten when welding in straight polarity (DCEN)?
- 30%
- 70%
- 50%
- None of the above
- What is the approximate melting temperature of pure aluminum?
- 1,200 degrees Fahrenheit
- 3,700 degrees Fahrenheit
- 1,300 degrees Fahrenheit
- 5,500 degrees Fahrenheit
- What is the approximate melting temperature of aluminum oxide?
- 3,700 degrees Fahrenheit
- 1,200 degrees Fahrenheit
- 1,330 degrees Fahrenheit
- 5,500 degrees Fahrenheit
- What is one of the advantages of using a gas lens over a colet body?
- Greater tungsten stickout
- Better gas coverage
- Less gas consumption
- All of the above
- What is an autogenous weld?
- A weld using only the base material
- A weld that is made for the auto industry
- A weld that is made automatic
- All of the above
- Why is it important to fill the crater when welding aluminum?
- When using GTAW, what should melt the filler rod?
- The arc
- The puddle