Why Argon Gas Is Used in Welding
Argon gas is used in welding because it acts as a shielding gas to protect the weld from contamination.
Argon is an odorless, colorless, and non-flammable gas that is stable and has low reaction rates.
It decreases the oxygen content in the air and is safe to use, but a well-ventilated work area is recommended.
Argon is an ideal shielding gas for working with aluminum and nonferrous metals.
It is cost-effective, readily available, and can be used in different mixtures depending on the type of metal being welded.
Universal Technical Institute teaches the use of argon as a shielding gas in gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) processes.
Pure argon is commonly used in both GMAW and GTAW, while mixtures of argon with carbon dioxide or helium are also used in specific applications.
Did You Know?
1. Argon gas was discovered in 1894 by the British scientist Lord Rayleigh and Scottish chemist William Ramsay. They observed that a gas was left behind after removing oxygen and nitrogen from air, which turned out to be argon.
2. Besides welding, argon gas is used in the manufacturing of energy-efficient windows. By injecting argon gas between the glass panes, it helps to reduce heat transfer and increase insulation, making the windows more energy-efficient.
3. Argon gas is the third most abundant gas in the Earth’s atmosphere, accounting for approximately 0.93% of the total composition. It is mostly inert, meaning it does not react easily with other elements.
4. The use of argon gas in welding creates an inert environment, protecting the weld from oxidation and preventing the formation of defects. This results in stronger, cleaner welds with less porosity.
5. Argon gas is also used in the preservation of cultural artifacts. Museums and art galleries often use argon gas to create an oxygen-free environment within display cases, preventing the deterioration of delicate and sensitive materials due to exposure to oxygen.
The Properties Of Argon Gas
Argon gas, a noble gas, plays a key role in welding due to its exceptional properties. This odorless, colorless, and tasteless gas makes up only 0.93% of the Earth’s atmosphere. With the element symbol Ar and an atomic number of 18, argon is known for its stability and low reaction rates. Being a noble gas, it is non-flammable and does not support combustion, ensuring the safety of welders during their work. Moreover, argon gas is non-toxic, although it does reduce the oxygen content in the air. Therefore, it is crucial to have a well-ventilated work area while using argon gas in welding.
Argon Gas As A Shielding Gas In Welding
In welding, shielding gases are used to protect the weld from contamination by elements such as oxygen, carbon dioxide, nitrogen, or water vapor. Argon gas, with its excellent shielding capabilities, is an ideal choice for working with aluminum and nonferrous metals. The use of argon gas as a shielding gas creates an environment that prevents the oxidation, discoloration, and porosity of the weld. By effectively shielding the weld pool from atmospheric contaminants, argon gas helps maintain the integrity and durability of the weld, resulting in high-quality and long-lasting welds.
Different Types Of Argon Gas Mixtures For Welding
Different types of welding jobs require specific mixtures of argon gas to optimize the welding process.
- Pure argon, with a purity of 99.99%, is commonly used for welding non-ferrous metals like aluminum, copper, nickel, and for Tungsten Inert Gas (TIG) welding.
- On the other hand, argon-carbon dioxide (CO2) mixtures, consisting of varying percentages of argon and 5-20% CO2, are frequently employed for carbon, low alloy, and some stainless steels.
- Argon-oxygen mixtures, with ratios of 95-99% argon and 1-5% oxygen, find their application in welding carbon and stainless steel.
- Moreover, argon-helium-carbon dioxide mixtures are also used depending on the type of steel being welded.
In summary, argon gas is an essential component in welding processes and its specific mixture plays a crucial role in achieving optimal results.
- Pure argon:
- Non-ferrous metals (e.g., aluminum, copper, nickel)
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Tungsten Inert Gas (TIG) welding
-
Argon-carbon dioxide mixtures:
-
Carbon, low alloy, and some stainless steels
-
Argon-oxygen mixtures:
-
Welding carbon and stainless steel
-
Argon-helium-carbon dioxide mixtures:
- Dependent on the type of steel being welded.
Safety Precautions And Equipment For Using Argon Gas
While working with argon gas, it is essential to prioritize safety measures. Welders typically use regulators and flow meters to control the argon flow, ensuring a secure working environment. Argon regulators are equipped with two gauges, one for measuring gas tank pressure and the other for monitoring the gas flow rate. This enables welders to effectively manage the gas supply.
The flow rate of argon gas is measured in cubic feet per hour (CFH), with industry-standard flow rates ranging between 10cfh and 35cfh. It is important to consider the duration of an argon welding tank, which depends on multiple factors – tank size, flow rate, and frequency of use. Welding tanks come in a variety of sizes, ranging from 20 cubic feet to 330 cubic feet.
To summarize:
- In welding, argon gas is controlled using regulators and flow meters.
- Argon regulators have gauges for measuring gas tank pressure and flow rate.
- The flow rate of argon gas is in cubic feet per hour (CFH), with recommended industry-standard flow rates between 10cfh and 35cfh.
- The duration of an argon welding tank depends on factors such as tank size, flow rate, and frequency of use.
- Welding tanks are available in sizes ranging from 20 cubic feet to 330 cubic feet.
Argon Gas In Gas Metal Arc Welding (GMAW) And Gas Tungsten Arc Welding (GTAW)
Gas Metal Arc Welding (GMAW) and Gas Tungsten Arc Welding (GTAW) are two commonly used welding methods. Both methods require the use of shielding gases, with argon gas being the preferred choice.
In GMAW, an electric arc is created between the metal and a wire electrode, with argon gas used as the shielding gas.
GTAW, also known as Tungsten Inert Gas (TIG) welding, uses an electric arc but with a nonconsumable tungsten electrode and an inert shielding gas like argon.
By utilizing argon as the shielding gas in these processes, welders can protect the weld pool from airborne contaminants and shape the penetration profile of the weldment.
The use of pure argon is standard for all applications of GTAW, while a blend of argon and carbon dioxide or helium is often chosen to enhance specific characteristics of the weld in GMAW.
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Frequently Asked Questions
Why is argon and CO2 used in welding?
Argon and carbon dioxide (CO2) are commonly used in welding due to their complementary properties. While argon alone can be used for welding, the addition of CO2 enhances the welding process. The combination of argon and CO2 deepens penetration and strengthens the arc, making it more suitable for out of position welding. Additionally, this combination produces less spatter and carries less heat compared to pure CO2, resulting in a cleaner weld. Together, argon and CO2 offer an affordable and precise welding solution.
Why is argon used as a shielding gas?
Argon is utilized as a shielding gas due to its remarkable properties. With its stability, nonflammable nature, and nontoxic composition, argon ensures a safe welding environment. As an ideal shield gas, argon effectively disperses impurities present in the atmosphere, safeguarding welds from oxidation and corrosion. By employing argon as a shielding gas, welders can achieve cleaner and stronger welds, enhancing the overall quality and durability of the welded materials.
Where is argon used in welding?
Argon is commonly used as a shielding gas in gas metal arc welding (GMAW) to protect the weld pool from contamination. GMAW is a versatile welding process that can be applied to various metals, including both thick and thin sheets as well as nonferrous materials. The use of argon as a shielding gas ensures a clean and high-quality weld by preventing atmospheric gases from coming into contact with the molten metal, resulting in a strong and durable joint.
Why is argon used in welding and not nitrogen?
Argon is used in welding instead of nitrogen due to its non-reactivity in the presence of electric arcs. Nitrogen, on the other hand, becomes reactive when exposed to the electric arc, compromising the quality and integrity of the weld. Additionally, argon’s lower thermal conductivity makes it more suitable for window insulation compared to nitrogen. In most other applications, however, nitrogen proves to be a better choice.