shielding gas（The Importance of Shielding Gases in Welding Processes）

The Importance of Shielding Gases in Welding Processes

What are Shielding Gases?

Shielding gases are essential to welding processes. They are gases that protect the area around a welding arc from atmospheric contamination. In other words, they are used to shield the molten metal from the air, preventing it from reacting and becoming compromised. Welding processes that require high heat often rely on the use of gas for shielding.

Common Shielding Gases Used in Welding

The most popular shielding gases are argon and carbon dioxide. While argon is the preferred gas for welding processes that require high heat, carbon dioxide is often used in instances when a high-speed shielding process is needed. A mixture of the two gases can also be used for some welding processes. Argon's slow-moving molecules make it easy to control the arc while welding. It is generally used in TIG (tungsten inert gas) and MIG (metal inert gas) welding processes. Carbon dioxide, on the other hand, is commonly used in MAG (metal active gas) welding processes. Carbon dioxide is ideal in MAG processes because it produces a high level of shielding while also promoting the ionization of metals.

How Shielding Gases Affect Weld Quality

The effectiveness of shielding gases in welding processes is the ultimate determinant of weld quality. Should a welding arc be exposed to atmospheric gases, the contaminants in the air can cause the metal to form brittle oxides that compromise the strength of the welded joint. These oxides, known as slag, can also cause the weld's appearance to be undesirable. Apart from weld appearance and joint strength, the right shielding gases can also promote a stable, smooth arc with shallow penetration, in turn resulting in consistent welds. Welding with the wrong gas can cause issues like sputtering, smoking, and improper fusion between the metal pieces. In summary, shielding gases play a vital role in the welding process, and the right gas or gas mixtures can be the determining factor for the quality of the final product. It's essential for welders to understand which gas to use, how to use it, and how it affects the welding process's outcome.