What Is TIG Welding inGTAW/TIG/STICK

GTAW/TIG/STICK

TIG WeldingAccording to the Welding Robots website, TIG welding is the primary method used within the industry. 

While TIG is typically more costly, time-consuming, and difficult, it produces high-quality welds. TIG welding requires the use of both hands and one foot to operate a foot pedal.

Bottom Line

• TIG welding produces cleaner and more precise welds than MIG welding or other Arc welding methods, making it the strongest. That said, different welding jobs may require different methods, while TIG is generally stronger and higher in quality, you should use MIG or another method if the job calls for it.

• Air-cooled torch bodies.

        I generally use my WP-17 body for just about everything however the other week I ran into a job that required me to weld inside a 1500$ stainless steel valve pipe (saving the threads), I got the job done using a button back cap and a stubby kit but, the torch was still about 3/4 of an inch too long to truly get the job done perfectly.
  
            Recently I acquired a WP-9 torch body, this torch uses the same collets and collet bodies as similar water-cooled torch bodies and, is overall roughly an inch shorter than the WP-17 body. Next time I need to get into a tight space I will be better equipped for the job!

PROBLEMS

 1.1 It has been suggested that compared to SMAW, the cooling rate is higher in GMAW and it is, therefore, more likely for heat-affected zone cracking to occur in hardenable steels. What is the main reason for the cooling rate to be higher in GMAW than SMAW?

 1.2 The diameter of the electrodes to be used in SMAW depends on factors such as the workpiece thickness, the welding position, and the joint design. Large electrodes, with their corresponding high currents, tend to produce large weld pools. When welding in the overhead or vertical position, do you prefer using larger or smaller electrodes?

 1.3 In arc welding, the magnetic field induced by the welding current passing through the electrode and the workpiece can interact with the arc and cause “arc blow.” Severe arc blow can cause excessive weld spatter and incomplete fusion. When arc blow is a problem in SMAW, do you expect to minimize it by using DC or AC for welding?

 1.4 In the hot-wire GTAW process, shown in Figure P

1.4, the tip of the filler metal wire is dipped in the weld pool and the wire itself is resistance heated by means of a second power source between the contact tube of the wire and the workpiece. In the case of steels, the deposition rate can 34 FUSION WELDING PROCESSES be more than doubled this way. Do you prefer using an AC or a DC power source for heating the wire? Do you expect to apply this process to aluminum and copper alloys?

 1.5 In GTAW the welding cable is connected to the tungsten electrode through a water-cooled copper contact tube, as shown in Figure 1.11. Why is the tube positioned near the lower end of the electrode instead of the top?

 1.6 Measurements of the axial temperature distribution along the GTAW electrode have shown that the temperature drops sharply from the electrode tip toward the contact tube. Why? For instance, with a 2.4-mm-diameter W–ThO2 electrode at 150 A, the temperature drops from about 3600 K at the tip to about 2000 K at 5 mm above the tip. Under the same condition but with a W–CeO2 electrode, the temperature drops from about 2700 K at the tip to about 1800 K at 5 mm above the tip (26). Which electrode can carry more current before melting and why?

 1.7 Experimental results show that in EBW the penetration depth of the weld decreases as the welding speed increases. Explain why. Under the same power and welding speed, do you expect a much greater penetration depth in aluminum or steel, and why? 

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1.8 How does the working distance in EBW affect the depth–width ratio of the resultant weld? 

1.9 Consider EBW in the presence of a gas environment. Under the same power and welding speed, rank and explain the weld penetration for Ar, He, and air. The specific gravities of Ar, He, and air for air are 1.38, 0.137, and 1, respectively, at 1 atm, 0°C. PROBLEMS 35 Shielding gas nozzle Weld metal Shielding gas Base metal Weld pool Arc Tungsten electrode Contact tube Cable 1 Wire feeder Filler wire 2nd power source Cable 3 Cable 4 Contact tube Figure P1.4 

1.10 Which arc welding process could have been used for joining the edge weld of thin-gauge steel shown in Figure P1.10 and why? 

1.11 Two 15-cm-thick steel plates were joined together in a single pass, as shown in Figure P1.11.Which welding process could have been used and why?