Here's why:
* CO2 is used for MAG welding (Metal Active Gas). MAG is a specific type of MIG welding using a shielding gas that is a mixture of argon and carbon dioxide**.
* MIG (Metal Inert Gas) uses inert gases like argon or helium for shielding. These gases are chemically inert and do not react with the molten weld pool.
* CO2 is not inert. It actually reacts with the molten metal, creating a slag layer. While this slag can be beneficial in certain applications, it can also create problems like porosity and brittle welds.
Here's a breakdown of why CO2 is used in MAG welding:
* Cost-effectiveness: CO2 is significantly cheaper than argon.
* Increased penetration: CO2 reacts with the molten metal, promoting greater penetration and allowing for thicker materials.
* Stable arc: CO2 provides a stable arc even at lower currents.
However, CO2 also has disadvantages:
* Lower quality welds: The slag layer can lead to imperfections like porosity and brittleness.
* Spatter: CO2 produces more spatter compared to inert gas shielding.
* Limited application: CO2 welding is not suitable for all materials and applications.
In summary: While CO2 is commonly used in MAG welding, it's not used for MIG welding. The use of CO2 in welding introduces a different set of characteristics compared to inert gases, leading to both benefits and drawbacks.
