Industrial gases play a pivotal role in a variety of fabrication and manufacturing processes, and among the most widely used is argon.
Named from the Greek word for ‘lazy’ or ‘inactive’, argon is indeed a truly inert gas, and one of six so-called ‘noble’ gases which occur naturally – all of them odourless, colourless and non-reactive.
Argon is also the most abundant, and most cost-effective, of the inert gases, which explains its wide use in manufacturing and other industrial processes. As a shielding gas, argon is used to improve quality, optimise performance and reduce costs in a variety of processes such as cutting and welding in the fabrication, automotive, and machine building industries.
Multiple industry applications
“There are multiple applications for argon in manufacturing and fabrication, and the demand is growing,” says Sean Young, welding specialist at Air Products South Africa. “As an inert gas, argon is an essential component in many processes where a completely non-reactive gas is needed, mostly to form a protective barrier from other gases.”
The shielding role that argon plays is especially fundamental to welding processes, including tungsten inert gas (TIG), gas tungsten arc or wire feed welding, as well as metal inert gas (MIG) welding.
“Argon is used as a shield gas in TIG welding, which uses a non-consumable tungsten electrode, and in MIG welding, which employs a consumable wire feed electrode. The function of the shielding gas is to protect the electrode and the weld pool against the oxidising effect of air,” explains Young.
“It is used either as a pure gas on its own or mixed with various other gases. Argon on its own is used in TIG welding applications to weld all types of materials, such as carbon steel, aluminium and copper. In some cases argon may have helium added to it to enhance the process.
“In MIG welding, argon is used on its own for the welding of copper and aluminium. When it comes to stainless steel, a mixture of argon with carbon dioxide or oxygen or nitrogen (known as a two-part mix) may be used. A mixture of argon with carbon dioxide and oxygen (commonly known as a three-part mix) may be used to weld a variety of carbon steels.”
In addition, a mixture of argon and carbon dioxide is often used for metal active gas (MAG) welding of ordinary structural steel, and in plasma-arc cutting and welding, where argon and hydrogen are combined to provide a very high temperature when used with a special torch.
Because argon provides protection against atmospheric contaminants, it plays a vital role in ensuring that the integrity of the weld is sound at all times, which is vital in the production of a quality end product.
Where there is metal manufacturing, there is argon
“The growing demand for argon is especially true in areas where economic growth and expansion are forecasted,” Young notes. “As long as there is a demand for the manufacturing of any type of carbon steel, aluminium or copper, argon will always be a prerequisite.”
Therefore, the availability of argon in the welding industry is of utmost importance, agrees Gary Lombard, CryoEase Business Manager at Air Products South Africa.
“As the largest producer of gaseous argon in the country, we have built up sufficient argon manufacturing and storage capacity to ensure a comfortable supply for our welding customers in the immediate and long term,” Lombard says.
The relevance and application of argon does not stop at welding, however. In metals manufacturing, argon also comes into its own, not only as a shielding gas.
“Argon is used as a shield gas in casting and stirring of ladles, but it has other applications,” Young notes. “These include the use of argon as a blowing gas during the manufacture of higher quality steels to prevent the formation of nitrides.
“When steel is made in a converter, a mix of oxygen and argon is blown into the molten metal. The addition of argon specifically reduces chromium losses, and the desired carbon content is achieved at a lower temperature.”
In aluminium manufacture, argon is also used to aid degasification and to remove dissolved hydrogen and particulates from molten aluminium. The inert properties of argon are also useful in the manufacture of titanium to prevent oxidation and reaction with nitrogen (as titanium is the only metal that will burn in a 100% nitrogen atmosphere).
Lighting the way
Other uses of argon in the manufacturing industry include the production of the ubiquitous light bulb. Here argon is used as a filler gas in the manufacture of both fluorescent and incandescent light bulbs.
“The use of argon excludes oxygen and other reactive gases and reduces the evaporation (sublimation) rate of the tungsten filament, thereby permitting higher filament temperature,” Young explains. “Most common of the mixtures is 93% argon and 7% nitrogen at a pressure of 70 kPa.”
He continues: “Also acting as a filler gas, argon is used between the glass panels of high-efficiency thermo pane windows as it is not only dry and colourless, but it is a relatively heavy gas that minimises heat transmission between glass window panels.”
Argon is also used in electronics with methane as a filler gas; as well as a high purity inert shield gas in the manufacture of silicon and germanium crystals used in the semiconductor industry.
Delivery method to suit the volume
The wide range of applications of argon is matched by the range of different volume users. Argon has the capacity to meet the needs of all Air Products’ manufacturing customers, from high-end users who may require a number of tonnes on a daily basis, to smaller consumers who may only need a couple of kilograms a month. Modes of delivery of liquid or gaseous argon therefore ranges from cylinder to CryoEase to bulk tanker supply.
“The majority of our argon customers recognise the advantages that CryoEase brings, which is suitable for customers requiring ten cylinders or more per month,” says Lombard.
Air Products’ CryoEase service offers a solution which is a combination of equipment and a delivery service. Replacing the often cumbersome need for rotating cylinders, the CryoEase customer makes use of just one tank on-site. This is replenished by Air Products on an ongoing basis, using the company’s CryoEase trucks which are designed specifically for easy access into smaller areas. The Telemetry forecasting system, which is fitted onto each tank, provides volume feedback to Air Products, who then schedule the next delivery without the customer worrying about low levels, and having to place an order.
Peace of mind
“CryoEase essentially ensures uninterrupted gas supply for the user. The system brings many other ‘hidden’ benefits too, such as minimising risk by eliminating the need for constant cylinder handling, better use of space, and increased productivity. This is because it minimises the time needed to restock, which is a critical factor - especially for companies using multiple welding points,” notes Lombard.
He adds that another benefit for argon users is that CryoEase guarantees the purity of the gas. “With a consistent supply, there is less chance of environmental contamination. So, CryoEase brings peace of mind for the user on many levels.”
A number of Air Products South Africa’s country-wide facilities have the capacity to produce argon, and storage sites are strategically placed across the country.
“Future demand for argon will be driven largely by infrastructural growth and development. This includes the construction of power plants, solar devices, wind farms; as well as basic infrastructure, such as roads, rail and ports,” notes Lombard.
“Our argon storages ensure consistent supply, but without expert supply chain management, our customers would not have peace of mind when it comes to their argon requirements. Air Products’ real value proposition lies in our flair for operational on-site management, as well as expertise in supply chain management.
“Our aim, apart from uninterrupted up-time and security of supply for our customers, is the assurance of a premium quality product. Purity is vital when it comes to argon. Our customers may be assured of this, thanks to Air Products’ decades of experience in argon production and quality assurance through our ISO9001:2000 certification.
“In addition, our customers can benefit from our welding expertise when it comes to choosing the right gas,” says Lombard noting that Air Products are industry leaders in specialty welding gas mixtures. Giving expert advice on how argon can assist and enhance a customer’s welding applications is part of the service ‘package’.
“Air Products’ specialist knowledge when it comes to argon and its applications, our operational and distribution expertise - being able to meet the needs of the smallest and largest argon user - ensures a supply chain that will reliably meet the South African manufacturing and fabrication sector requirements currently and into the future,” Lombard concludes.