Gas Tungsten Arc Welding (GTAW) or Tungsten Arc Welding (TAW) can be used with a large variety of metals and can be applied to several industries. It welds two or more workpieces using a tungsten electrode and is similar to Metal Inert Gas (MIG) Welding. It is used to weld stainless steel and non-ferrous metals.
It is complex and difficult to master, and thus it is very highly valued in various fields. This process grants the operator very high control over the weld. Though similar in process, plasma arc welding uses a slightly different welding torch giving varying results.
The weld spot is protected from many inert gases. This process reduces the use of filler metal thus saving enormous cost and increases efficiency and preserves the quality by not contaminating the core metal.
Benefits of TIG Welding
As there is no contamination of metal their results are exponential. The quality and strength of welds are rather high due to the factors, only if implemented properly. The success of this welding process hinges on various factors such as the choice of shielding gas, welding wire, tungsten electrode, and the welding technique.
This welding technique is also widely used in space vehicle preparation as well as industries that use thin tubing. It is also very helpful in repair and maintenance work. Unlike most welding processes, with tungsten inert gas the weld metal is not transferred straight across electric arcs.
- TIG / GTAW Power Supply
The power supply for welding is one of the bulkier tools used in the process. However, as technology improves, the machines used are becoming smaller.
Though the majority use Direct current, some use Alternate current too.
- Welding Process
In the welding process setting, you should choose the option specified for TIG welding. This is usually labeled as TIG or GTAW High-Frequency Impulse.
- Pre Flow and Post Flow
This setting is responsible for controlling the inert gas flow into your welding application.
- Step 1: Prepare the workpiece
- Step 2: Prepare your equipment
- Step 3: Set up your machine
- Step 4: Start welding
- The welds formed are highly resistant to corrosion.
- Welds thin metal sheets.
- Produces good quality welds with precision
- It is a clean process because of less emission of fumes, sparks, spatter and smoke.
- It offers greater visibility during the operation due to less emission of smoke and fumes.
- It is a complex process and difficult to master.
- It is not portable and hence suitable for welding shops only.
- It is a slower welding process as compared with other welding processes.
When welding components, a shielding gas is used to protect the underside of the weld pool and weld bead from oxidation. To reduce the amount of gas consumed, a localized gas shroud for sheet, dams or plugs for tubular components is used. As little as 5% of air can result in a poor weld bead profile and may reduce corrosion resistance in materials like stainless steel. With gas backing systems in pipe welding, pre-weld purge time depends on the diameter and length of the pipe. The flow rate and purge time are set to ensure at least five volume changes before welding.
TIG welding is a bit more expensive than MIG welding but is the recommended method if appearance is important. There is no spatter created during the weld because the non-consumable tungsten electrode does not use any filler material. This method does require a higher level of operator training and expertise. Argon is the most commonly used gas for TIG welding.
If the amount of current used exceeds the capability of the electrode, tungsten inclusions in the weld may result. Known as tungsten spitting, this can be identified with radiography and can be prevented by changing the type of electrode or increasing the electrode diameter. In addition, if the electrode is not well protected by the gas shield or the operator accidentally allows it to contact the molten metal, it can become dirty or contaminated. This often causes the welding arc to become unstable, requiring that the electrode be ground with a diamond abrasive to remove the impurity.
Tig Welding Course at ASTI DUBAI
At ASTI Dubai, this complex procedure is explained to the students in simple steps. It enables the students to learn more and experience this convoluted processes simply so that they can enhance their skills.
There are lots of related courses available at ASTI for students to improvise. Giving opportunities to students through vocational courses is the prime objective. Also, there are many laboratories and the structures are unique for students to learn and cultivate new ideas.
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