Final answer:
The gases that can be used as shielding gases for GMAW include carbon dioxide, argon-oxygen mixtures, and argon. All of these gases help to protect the welding arc from atmospheric contamination, with each offering different properties to optimize welding performance.
Step-by-step explanation:
The gases that can be used as shielding gases for GMAW (Gas Metal Arc Welding), also known as MIG (Metal Inert Gas) welding, include:
- Carbon dioxide
- Argon-oxygen
- Argon
- All of the above
Each of these gases serves the purpose of protecting the welding arc from contaminants in the atmosphere. Carbon dioxide is an active gas and is often used in its pure form or mixed with other gases to achieve desired welding properties. Argon, being an inert gas, is commonly used for its excellent coverage and stable arc characteristics, and argon-oxygen mixtures are used to get the benefits of both inert and active properties.