Types Of Welding Gases | MIG VS. TIG

Types of welding gases and which gas is used in which process:

There is no single welding process that can be applied for all welding applications. The procedure must be altered depending on the type of material to be welded.

Whether the metal is ferrous or non-ferrous, magnetic or non-magnetic, and what the metal’s intended usage is.

These factors will also influence the type of welding gas used. We’ll also go over what gas is used for tig welding in this comprehensive tutorial.

Types Of Welding Gases, Used in Welding Process?

Gases are employed in two of the most common welding processes.

Gas Metal Arc Welding: An arc created by an electrical current between the metal and the wire shielded by a shielding gas heats the wire to the melting point, and a wire welding electrode on a spool is automatically fed onto the two weld piece ends to be brought together.

Gas Tungsten Arc welding: Gas Tungsten Arc Welding (GTAW or TIG Welding) warms the filler metal placed on two weld piece ends to be welded together. A constant current power supply is used to create an arc by passing a column of ionized gas and metal vapors through it (plasma).

What role do gases play in MIG and TIG welding?

Shielding gases are frequently used in gas metal arc welding (MIG) and gas tungsten arc welding to protect the weld region from oxygen and water vapor (TIG).

Welding becomes more difficult and weld quality suffers as a result of the presence of oxygen and water in the atmosphere.

Because shielding gases are often denser than air, they can wrap around the weld and disperse gas at low flow rates. They are either inert (noble gases) or semi-inert (common gases).

Helium and argon are the two types of welding gases used in welding.

They can be used in their purest form, or mixed or blended with other semi-inert gases such as carbon dioxide, hydrogen, or nitrogen to improve weld characteristics on specific metals.

In the welding process, shielding gases have a number of advantages:

• It protects the welding arc.
• Without the material oxidizing, welding at high temperatures is possible.
• The metal is transferred across the arc with very little alloying component loss.
• Splatter and burn-in are two undesirable side effects that can be decrease.
• Individual gases can be tweaked to fit the welded material’s requirements.

What Is the Importance of Gas Blends?

The liquid metal pool created during the welding process is protected from contamination by the atmosphere by shielding gases.

They work by eliminating potentially reactive gases from the weld region, such as oxygen and nitrogen, as well as water vapor. They can also improve metal transfer and keep the arc stable.

Furthermore, the interaction of the shielding gases with the base metal and filler metal may change the basic mechanical properties of the weld area. This has an effect on the material’s strength, hardness, and corrosion resistance.

The various shielding gases used in welding have distinct properties and functions. The most often used ones are shown in this table.

What gas is used for tig welding?

Hydeogen (H2), Argon (Ar), Helium (He), Nitrogen (N2), Carbon Dioxide ( CO2), Oxygen (O2)

Mixtures of two or three types of welding gases are widely used to increase weld efficiency and quality for specific base metals and filler metals.

The composition of the shielding gas can be changed to manage the distribution of heat to the weld. As a result, the weld metal cross-section form and welding speed may be changed.

Welding speed can be increased greatly. Because labor costs make up such a huge amount of overall welding costs, this can save you a lot of money.

MIG Welding Gas

A variety of gases and gas combinations can be used in MIG welding. We’ll look over them in greater detail once we list them:

The type of material you’re welding determines which one you should use.

Carbon Steel And Low Alloy Steel

Argon can be used to join carbon and low alloy steels when mixed with CO2 in a 75/25 ratio to improve weld penetration and bead wetting properties.

Stainless Steel

Tri-mix combinations of argon, helium, and CO2 in a 90 percent /7.5 percent /2.5 percent ratio are ideal for welding stainless steel because they give good arc stability and depth of fusion.

Aluminum

Argon is used to weld aluminum in the majority of cases. However, if the metal being welded is thicker than 12 inches, Helium may be used to promote heat penetration.

Nickel Alloys

To increase penetration and weld pool flow, the most common gases used to weld nickel alloys are either 100 percent pure argon or a 60 percent/40 percent mixture of argon and helium.

Copper Alloys

Pure argon or a 75 percent/25 percent mixture of argon and helium are the most common types of welding gases used to weld copper alloys. This improves the weld pool’s penetration and flow.

TIG Welding Gas

Pure Argon is likely the most used type of shielding gas for TIG welding because it can be used on any metal, including aluminum.

Pure argon provides good arc stability and requires less cleaning action since the arc is short and concentrated, allowing for a precise weld with little bead rollover. It usually produces a finished weld that is brighter and shinier.

Argon and helium, with helium accounting for half of the mix, enable hotter welds while working, resulting in a wider heat profile and better heat conduction.

It’s the second most common TIG welding shielding gas, and it’s also used for several unique applications. The increased heat, though, comes at a cost, so keep an eye on the weld to make sure you’re not melting the metal.

Pure helium or large volumes of helium (He-90 percent, Ar-10 percent) are used as shielding gas in TIG welding with direct current electrode negative (DCEN).

As seam welders, the GTAW – DCEN combination is often utilized. Due to the high heat input from the gas used, fast welding speeds and great penetration may be accomplished.

Last but not least, there’s pure hydrogen. Welders may choose to use hydrogen in some situations since it increases the heat input while welding.

It creates a hotter, wider bead that penetrates deeper into the metal. When working with stainless steel, this is really beneficial.

Welding Gases Safety

Gases are difficult to detect since they are invisible. Users may suffer from asphyxiation, burns, or other injuries as a result of using them.

Welders should be aware of the following welding safety precautions and recommendations.

The National Ag Safety Database recommends the following safety precautions:

• Inspect the equipment for leaks at all connections using an approved leak-test solution.
• Look for leaks and worn places on the hoses.
• Damaged hoses should be replaced as soon as possible.
• Sparks, flames, and hot metal should be kept away from hoses and cylinders.
• Use a flint lighter to spark the flame.
• Stand to the side when opening cylinder valves (away from the regulators).
• Progressively open cylinder valves to prevent sudden high pressures from exploding the regulators.
• Only 1/4 to 3/4 turn the acetylene cylinder valve open; leave the wrench in place so the cylinder may be quickly closed in an emergency.
• Fire the acetylene first, then set the oxygen to a neutral flame.
• Close the acetylene torch valve first when turning off the torch ( a “pop” might occur as the oxygen “blows out” the flame, but this eliminates the possibility of the flame burning up the acetylene line).
• Closing the cylinder valves, bleeding the lines to reduce pressure on the regulators, coiling the hoses neatly, and replacing the equipment
• Keep a fire extinguisher handy at the welding site.

FAQs

What exactly is gas welding, and what are the various types of it?

Gas welding is a type of welding that involves the use of a gas such as oxygen, acetylene, helium, argon, or hydrogen. The type of gas utilized depends on the weld type. Because of the gas combination used, the flame is hotter, allowing for more penetration.

What is a shielding gas in welding?

Shielding gas is used in welding to prevent contamination of the liquid metal pool created during the welding process by the atmosphere, resulting in a better weld. In MIG and TIG welding, this is a common occurrence.

What exactly is gas welding equipment and how does it function?

Gas welding equipment includes a MIG or TIG welder, gloves, lenses, aprons, a table, regulators, flames, tips, and gas mixers.

What is the principle of gas welding?

Gas welding makes use of specialized gas combinations to create a hotter, more concentrated flame than standard welding flames. This allows for more metal penetration, resulting in stronger welds, as well as the capacity to weld larger chunks of metal than would otherwise be possible without gas welding.

Conclusion

The shielding welding gas is used in MIG and TIG welding which is critical to the process’s success.

To achieve sufficient penetration, uniform beading, and excellent welding results when welding using MIG or TIG welding techniques, the correct shielding gas must be used.

The incorrect shielding gas causes poor penetration, uneven bead morphologies, severe spatter, overheating, lack of arc control, and quick electrode burning.

It’s vital to understand which gases to use and how to use them safely.