TIG WELDING PROCESS
Tungsten Inert Gas (TIG) welding, also known as Gas Tungsten Arc Welding (GTAW), uses a non-consumable tungsten electrode to produce the weld. Here’s a basic diagram and description of the components involved in a TIG welding setup:
1. *Power Supply*: Provides the electrical current necessary for welding. It can be set for either alternating current (AC) or direct current (DC), depending on the materials being welded.
2. *TIG Torch*: The torch holds the tungsten electrode and directs the welding current to the workpiece. It also provides the shielding gas that protects the weld area from contamination.
3. *Tungsten Electrode*: A non-consumable electrode that carries the welding current and produces the arc.
4. *Shielding Gas*: Inert gas (usually argon or helium) that flows through the torch to protect the weld area from atmospheric contamination.
5. *Filler Rod*: A consumable rod that is manually fed into the weld pool to add material to the joint (optional depending on the weld).
6. *Workpiece*: The material being welded.
7. *Ground Clamp*: Connects the workpiece to the power supply to complete the electrical circuit.
Here's a simple textual representation of a TIG welding setup:
Power Supply
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(AC/DC)
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TIG Torch Ground Clamp
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Tungsten Workpiece
Electrode
/
/
Shielding Gas
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(Inert Gas)
In a diagram, you’d see these components connected to each other, with the TIG torch directed at the workpiece and the ground clamp attached to the workpiece as well. The shielding gas would flow through the torch to envelop the tungsten electrode and the weld pool.
[1:28 PM, 7/22/2024] santhoshkumar25mech: Components of a TIG Welding SetupPower Supply:Function: Provides the necessary electrical current to create an arc between the tungsten electrode and the workpiece.Types: Can be set to alternating current (AC) for welding materials like aluminum and magnesium or direct current (DC) for welding most other metals such as steel and stainless steel.TIG Torch:Function: Holds the tungsten electrode and delivers the welding current to the workpiece.Parts:Collet Body: Holds the tungsten electrode in place.Gas Lens: Ensures smooth flow of shielding gas.Nozzle (or Cup): Directs the shielding gas to the weld area.Tungsten Electrode:Function: Acts as the source of the arc, which generates the heat necessary for welding.Properties: Tungsten is chosen for its high melting point and good electrical conductivity.Types: Thoriated, ceriated, lanthanated, and pure tungsten electrodes, each suitable for different types of welding.Shielding Gas:Function: Protects the weld area from atmospheric contamination (oxygen, nitrogen, hydrogen) which can cause defects like porosity and oxidation.Types: Commonly argon, helium, or a mixture of both.Flow Rate: Typically set between 10 to 20 cubic feet per hour (CFH), depending on the application.Filler Rod:Function: Provides additional material to the weld joint, if necessary. It’s manually fed into the weld pool.Selection: Chosen based on the material being welded. For example, ER70S-6 is a common filler rod for carbon steel.Workpiece:Description: The metal pieces that are being joined together.Preparation: Cleaned and sometimes beveled to ensure a strong weld.Ground Clamp:Function: Completes the electrical circuit by connecting the workpiece to the power supply.Importance: Ensures stable current flow and helps prevent electrical shocks.Process of TIG WeldingSetup: Attach the ground clamp to the workpiece. Ensure the tungsten electrode is correctly placed in the torch and protrudes slightly from the nozzle. Set the power supply to the correct current type (AC or DC) and adjust the current settings.Shielding Gas: Turn on the shielding gas and set the flow rate.Striking the Arc: Position the torch at an angle of about 15-20 degrees from vertical. Bring the tungsten electrode close to the workpiece (about 1/8 inch away) and initiate the arc using a foot pedal or a button on the torch.Creating the Weld Pool: The arc melts a small area of the workpiece, forming a weld pool. Maintain a steady hand to control the size and shape of the pool.Adding Filler Metal (if needed): If additional material is required, manually feed the filler rod into the leading edge of the weld pool, melting it to form the weld.Progressing the Weld: Move the torch along the weld joint at a steady pace, maintaining the arc length and shielding gas coverage.Ending the Weld: Gradually reduce the current to avoid cratering (a dip at the end of the weld) and turn off the arc.Post-Weld: Allow the weld to cool while still under the shielding gas to prevent oxidation. Inspect the weld for quality and defects.Diagram of TIG Welding SetupHere's a more detailed diagram showing the connections and components:Power Supply
| (AC/DC)
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TIG Torch Ground Clamp
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Tungsten Workpiece
Electrode
/
/
Shielding Gas
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(Inert Gas)In a graphical representation, this would show:The TIG torch with the tungsten electrode and shielding gas nozzle directed at the workpiece.The ground clamp attached to the workpiece, completing the circuit.The power supply with connections to both the torch and ground clamp.Understanding each part and its function helps in setting up and operating the TIG welding process effectively.
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