13 Key Advantages and Disadvantages of Gas Tungsten Arc Welding | Applications of GTAW Welding

13 Key Advantages and Disadvantages of Gas Tungsten Arc Welding | Applications of GTAW Welding

What is Gas Tungsten Arc Welding (GTAW)?  |Advantages and Disadvantages of Gas Tungsten Arc Welding | Applications of Gas Tungsten Arc Welding (GTAW)

What is Gas Tungsten Arc Welding (GTAW)

Gas Tungsten Arc Welding (GTAW) is a type of arc welding that creates an arc between a non-consumable tungsten electrode and the weld pool.

The method is used with a shielding gas and without the usage of pressure. GTAW is suitable for use with or without the inclusion of filler metal (Autogenous).

Gas tungsten arc welding (GTAW), commonly known as tungsten inert gas (TIG) welding, is an arc welding technology that produces welds with a non-consumable tungsten electrode.

An inert shielding gas protects the weld region and electrode from oxidation and other ambient contaminants (argon or helium).

A filler metal is typically employed, however, some welds, known as autogenous welds or fusion welds, do not.’ Heliarc welding is a type of welding that uses helium.

A constant-current welding power supply generates electrical energy, which is carried across the arc by a plasma, a column of highly ionized gas and metal vapors.

The Constant Current (CC) power source can be used with either dc or ac power; the decision is mostly determined by the metal to be welded.

GTAW is most typically used to join thin pieces of stainless steel and nonferrous metals like aluminum, magnesium, and copper alloys.

The procedure gives the operator more control over the weld than rival processes like shielded metal arc welding and gas metal arc welding, resulting in stronger, higher-quality welds.

GTAW, on the other hand, is substantially more complex and difficult to master, and it is also significantly slower than most other welding processes.

Plasma arc welding, a related method, employs a slightly different welding torch to create a more focused welding arc and, as a result, is commonly automated.

Gas Tungsten Arc Welding Process

Owing to the coordination required by the welder, manual gas tungsten arc welding is a relatively challenging welding procedure.

GTAW, like torch welding, usually necessitates the use of two hands, as most applications require the welder to manually feed filler metal into the weld area with one hand while manipulating the welding flame with the other.

It is also critical to keep the arc length low while avoiding contact between the electrode and the workpiece.

A high-frequency generator (similar to a Tesla coil) delivers an electric spark to strike the welding arc.

This spark provides a conductive conduit for the welding current through the shielding gas, allowing the arc to be ignited while the electrode and workpiece are separated by 1.5–3 mm (0.06–0.12 in).

Once the arc is formed, the welder swings the torch in a small circle to form a welding pool, the size of which is determined by the size of the electrode and the quantity of current.

The operator then moves the torch back slightly and tilts it backward about 10–15 degrees from vertical while maintaining a constant spacing between the electrode and the workpiece.

Filler metal is manually added to the front end of the weld pool as needed.

Welders frequently create a technique in which they rapidly alternate between moving the torch ahead (to advance the weld pool) and adding filler metal.

Each time the electrode advances, the filler rod is withdrawn from the weld pool, but it is always kept inside the gas shield to avoid oxidation of its surface and contamination of the weld.

Filler rods made of low-melting-temperature metals, such as aluminum, necessitate that the operator keep a safe distance from the arc while remaining inside the gas shield.

If the filler rod is held too close to the arc, it may melt before making contact with the weld puddle.

As the weld nears completion, the arc current is frequently gradually lowered to allow the weld crater to solidify and avoid crater cracks from forming at the weld’s end.

Applications of Gas Tungsten Arc Welding

Gas Tungsten Arc Welding is most typically used to weld stainless steel and nonferrous materials such as aluminum and magnesium, but it may be used to weld almost any metal with the notable exception of zinc and its alloys.

Its applications involving carbon steels are limited not due to process constraints, but due to the availability of more cost-effective steel welding processes such as gas metal arc welding and shielded metal arc welding.

Furthermore, depending on the welder’s competence and the materials being welded, GTAW can be accomplished in a number of non-flat situations.

Gas tungsten arc welding is the most commonly used arc welding process for joining metals that contain alloys containing aluminum, magnesium, or copper.

For example, the material costs of aluminum are lower when using this welding process.

It is also used to weld stainless steel and for some titanium weld applications due to its ability to avoid impurities like silicon in the weld metal and better control of heat input than its rival metal inert gas (MIG) processes.

GTAW is generally more expensive than MIG welding, but the potential savings by eliminating the purchase of consumable electrode rods and allowing the welder to control welding parameters with better precision are typically considered to be worth it.

Advantages and Disadvantages of Gas Tungsten Arc Welding

Advantages of Gas Tungsten Arc Welding

1. High-quality welds

Gas Tungsten Arc Welding is used to join metals that contain alloys containing aluminum, magnesium, or copper. GTAW welds are very high-quality welds because there is little to no spatter and there is minimal heat input. GTAW welds are also super smooth and very strong.

2.  High deposition rates with a super-clean weld joint

Gas Tungsten Arc Welding has a very high deposition rate. Because of this deposition rate, it takes less time to make the required weld area thick enough to ensure a strong weld joint.

Because of this, the final weld joint is very clean with no flow or porosity.

3.  No filler metal used for welding small diameters

The amount of plasticity that gas tungsten arc welding has can be seen on smaller diameter pieces of metal. It works very well with small diameters such as 1/8″ (3 mm) or 3/16″ (5 mm).

It is very difficult to weld small diameters with a MIG welder because there needs to be a specific contact tip size and the welder usually has to move the wire extremely fast.

4. Gas Tungsten Arc Welding is Faster

Gas Tungsten Arc Welding is also faster than many other arc welding processes such as shielded metal arc welding and gas metal arc welding.

Gas Tungsten Arc Welding is the most commonly used arc welding process for joining metals that contain alloys containing aluminum, magnesium, or copper.

5. Gas Tungsten Arc Welding is a wide variety of materials

Gas Tungsten Arc Welding is an excellent process to use on a wide variety of materials. As this process uses a tungsten electrode in some cases you can use it on stainless steel and even titanium.

The deposition rates are very high and as a result, the time spent doing a project using this process is reduced.

Gas Tungsten Arc Welding can also be used on thin pieces of material.

6. Superior root pass weld penetration

Gas Tungsten Arc Welding will penetrate the root pass weld better than many other arc welding processes.

The materials used in gas tungsten arc welding are also not as difficult as some other welding processes like shielded metal arc welding or gas metal arc welding. In gas tungsten arc welding, the heating of the weld pool is also more effective.

7. Gas Tungsten Arc Welding is versatile

Gas Tungsten Arc Welding is excellent for joining a wide variety of alloys including stainless steel and titanium.

Gas Tungsten Arc Welding also offers a lot of flexibility when it comes to selecting filler materials. Welder’s rods are available with a wide variety or metal powders, allowing the weld joint to be tailored to provide the best mechanical properties possible for the application.

8. Better Control

Because it allows for more control over the weld area than other welding methods, gas tungsten arc welding may generate high-quality welds when conducted by trained operators. Maintaining cleanliness ensures maximum weld quality—all equipment and materials used must be free of oil, moisture, dirt, and other contaminants, which induce weld porosity and, as a result, a loss in weld strength and quality.

Disadvantages of Gas Tungsten Arc Welding

1.  Slow welding compared to SMAW, GMAW or SAW

Gas tungsten arc weld process is not as fast as many other processes like GMAW, SAW or SMAW.

2. Gas Tungsten Arc Welding is not used to join some alloys

Gas Tungsten Arc Welding is not used to join some alloys that are needed for certain industries

Gas tungsten arc welding would be ineffective when joining certain alloys like magnesium-aluminum alloy.

3.  Higher costs than MIG welding

Gas Tungsten Arc Welding costs more than other standard arc welding processes.

However, the potential savings by eliminating the purchase of consumable electrode rods and allowing the welder to control welding parameters with better precision are typically considered to be worth it.

4. Gas Tungsten Arc Welding is not used on all types of metals

Gas tungsten arc welding is not used on all materials because there are some metals that cannot be welded with this process such as copper, magnesium, or aluminum.

5.  Not easy to use in drafty environments due to loss of gas shielding

Gas tungsten arc welding is not easy to use in a drafty environment because of the large amounts of shielding gas that is needed to protect the weld area.

Gas Tungsten Arc Welding FAQs

1. Difference between GMAW and GTAW?

A disposable electrode is used in GMAW. As a result, the electrode material melts and deposits on the weld bead.

Because GTAW and TIG welding uses non-consumable electrodes, no electrode material is deposited on the weld bead. Because the electrode (or filler) is continuously fed by a mechanical system, the GMAW process is substantially faster.

An inert shielding gas is used, the same as in GMAW welding. In contrast to GMAW, which employs a wire that also serves as a filler material, GTAW warms things by using a tungsten electrode that delivers current to the welding arc. The welding arc melts the metal, forming a liquid pool.

  1. 2. What are the main applications of GTAW?

Although it is aerospace sector that is a major consumer of gas tungsten arc welding, the technology is also employed in a variety of other industries.

GTAW is widely used in many industries for welding thin workpieces, particularly nonferrous metals.

It is widely utilized in the production of space vehicles and is also regularly used to weld small-diameter, thin-wall tubing, such as that used in the bicycle industry.

Furthermore, GTAW is frequently utilized to construct root or first-pass welds for a variety of piping sizes.

The procedure is often used in maintenance and repair operations to fix tools and dies, particularly those constructed of aluminum and magnesium.

Because the weld metal is not transmitted directly across the electric arc as in most open arc welding techniques, the welding engineer has access to a wide range of welding filler metal.

No other welding technology, in fact, allows for the welding of so many metals in so many product configurations.

Volatilization can cause filler metal alloys, such as elemental aluminum and chromium, to be lost through the electric arc. The GTAW method does not result in this loss.

GTAW welds are highly resistant to corrosion and cracking over long time periods because the resulting welds have the same chemical integrity as the original base metals or match the base metals more closely, making GTAW the welding procedure of choice for critical operations such as sealing spent nuclear fuel canisters before burial.

3. What is the difference between SMAW and GMAW?

Another fusion welding technology is gas metal arc welding (GMAW), which creates an arc between a continuous bare electrode and conductive base plates.

Unlike SMAW, which uses a small rod-like electrode, GMAW uses a wire electrode with a very long length.

4. What is the difference between TIG and GTAW?

Gas tungsten arc welding (GTAW) is also known as hand-arc welding or hand-fusion welding, and it uses a tungsten rod to form a pool of molten metal before an arc is struck.

It differs from the process of TIG weldment because TIG has a smaller filler wire diameter, allowing the weld bead to be larger. This results in easier penetration.

5. What is GMAW?

GMAW uses a continuous wire electrode that is fed through a consumable (used once) or self-shielding gas metal arc welding unit. The weld puddle is typically created by using a constant current power source

GTAW Process

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