In the first part of this two-part blog, we covered the use of shielding gas in arc stud welding and the role it plays in helping to form a strong weld. Shielding gas essentially protects a weld point from exposure to potential contaminants like oxygen and moisture. With shielding gas, welders can eliminate potentially porous welds prone to corrosion. In the stud welding industry, shielding gas is typically used with drawn arc welding to replace the need for a flux and ferrule ring system. If you’re working with the stud welding process for any project, Northland Fastening Systems can provide any tools, studs, and welding accessories you might need, in addition to the expert advice of our own staff of stud welding technicians. As a comprehensive supplier for the stud welding process NFS has what you need for drawn arc, CD, and short cycle welding.
There are several types of shielding gas available to the welding industry, varying in price, production capabilities, and overall effectiveness. Choosing the right shielding gas for your stud welding process depends on your budget, desired finished properties of your weld, welding materials, pre- and post-weld cleanup abilities, and production schedule.
There are four common shielding gas types used in most welding processes: carbon dioxide, argon, oxygen, and helium.
- Carbon dioxide: The most common and least expensive shielding gas on the market, CO2 is the only gas that can be used in pure form without inert gas added. CO2 also helps to achieve a deep weld on thicker materials. However, it can create a low stability arc resulting in spatter when other gases are added, and it’s only useful in short circuit operations.
- Argon: The results of using an argon shielding gas are generally considered the best quality, both cosmetically and functionally. A mix of 75 to 95% argon with 25 to 5% CO2 is an ideal ratio for arc stability, minimal spatter, and a controlled puddle. Argon can also increase production rates with a spray transfer technique. Although argon is an abundant resource, it’s slightly more expensive than other shielding gases because of the difficult containment process.
- Oxygen: When used in small ratios, oxygen can help control fluidity of weld puddles, penetration, and arc balance. Oxygen is useful for mild carbon and stainless steel, but it can cause oxidation in aluminum, magnesium, copper, and other metals.
- Helium: Used with argon in similar ratios as argon/CO2 mixes (25% helium to 75% argon), helium provides deep penetration. Ratio adjustments offer control of arc heat/travel speed and increased productivity. Helium is also generally used in a mix of argon and CO2. Overall, helium is on the pricey side so it’s often added in as small amounts as possible.
Choosing the right type of shielding gas will go a long way in supporting quality weld results and increasing your production schedule. To learn more about the stud welding process and the complete line of supplies we offer, contact Northland Fastening Systems today at (651) 730-7770 or request a quote online.