What Gas to Use With TIG Welder
Gas tungsten arc welding, commonly known as TIG welding, is a versatile and precise welding process that requires the use of a shielding gas. This gas is essential for protecting the weld pool from atmospheric contamination, ensuring a clean and high-quality weld. While there are various types of gases available for TIG welding, it is important to select the right gas for your specific application. In this article, we will explore the different gases used in TIG welding and provide answers to some frequently asked questions.
Types of Shielding Gases for TIG Welding:
1. Argon: Argon is the most commonly used gas in TIG welding due to its excellent shielding properties. It is an inert gas that does not react with the molten metal, preventing oxidation and reducing the risk of defects in the weld. Argon also offers good arc stability and is suitable for welding a wide range of materials, including steel, stainless steel, aluminum, and titanium.
2. Helium: Helium is another inert gas that can be used for TIG welding. It has a higher thermal conductivity than argon, which makes it a better choice for welding materials with high heat conductivity, such as copper and aluminum. Helium also provides a hotter arc, resulting in deeper penetration and faster travel speed. However, it is more expensive than argon and can cause a more unstable arc, requiring more skill to control.
3. Argon-Helium Mixtures: To combine the benefits of both argon and helium, a mixture of the two gases can be used. The ratio of argon to helium can be adjusted depending on the specific welding application. Argon-helium mixtures are often used for welding thick sections of aluminum or for achieving deeper penetration in stainless steel welding.
4. Argon-CO2 Mixtures: Adding a small percentage of carbon dioxide (CO2) to argon can enhance the arc stability and increase the penetration in some types of steel welding. This gas mixture, known as C-25, is commonly used for welding mild steel. However, it is not recommended for welding materials like stainless steel or aluminum as it can result in poor weld quality.
Frequently Asked Questions:
Q: Can I use pure helium for TIG welding?
A: While pure helium can be used for TIG welding, it is not commonly recommended. Helium has a hotter arc, which can cause greater heat input into the workpiece and result in distortion or burn-through, especially for thinner materials. It is best to use helium in combination with argon for a more controlled arc.
Q: How do I know which gas to use for my specific welding job?
A: The choice of shielding gas depends on factors such as the type of material being welded, its thickness, and the desired weld characteristics. It is advisable to consult the welding procedure specifications (WPS) or seek guidance from experienced welders or welding instructors to determine the most suitable gas for your application.
Q: Can I use the same gas for both TIG and MIG welding?
A: While argon is commonly used for both TIG and MIG welding, it is important to note that the gas flow rates and mixtures may vary. TIG welding typically requires a lower flow rate compared to MIG welding. Additionally, the choice of shielding gas for MIG welding depends on the specific material being welded.
In conclusion, selecting the right gas for TIG welding is crucial for achieving high-quality welds. Argon is the most commonly used gas due to its excellent shielding properties, while helium is suitable for materials with high heat conductivity. Argon-helium mixtures and argon-CO2 mixtures provide additional benefits for specific welding applications. It is important to consider the type of material, thickness, and desired weld characteristics when choosing the appropriate gas. Consultation with experts and referring to welding procedure specifications can help ensure the correct selection of shielding gas for your specific welding job.