What is the fine-grained topic of the following text: Other gases are also used for this purpose such as Argon, Helium, Carbon Dioxide, and the gases given off when the flux burns away during SMAW (stick) welding.They provides a shielding effect which make a barrier between the outside oxygen and molten metal.The formation of oxide reduce the strength of the weld. Only return the topic.
Shielding gases in welding