Answer :
[tex]C_2_5[/tex] gas, a mixture of [tex]CO_2[/tex] and argon, is advantageous for welding mild steels because it provides a faster response to fouling on heat-transfer surfaces and changes in coolant temperatures, improving weld quality.
The question is about the advantages of using [tex]C_2_5[/tex] gas over [tex]CO_2[/tex] for welding mild steels. [tex]C_2_5[/tex], a mixture of [tex]CO_2[/tex] and argon, provides faster response to fouling on heat-transfer surfaces and to changes in inlet coolant temperature. It is beneficial because of its properties which positively affect the welding process.
Mild steel, containing up to about 0.25% of carbon, is commonly used in structures due to its strength and hardness over pure iron. When welding, the choice of a shielding gas can significantly impact the quality and characteristics of the weld. [tex]C_2_5[/tex] can help reduce spatter, improve arc stability, and result in less oxidation of the weld metal.
Supercritical carbon dioxide (sc[tex]CO_2[/tex]) is gaining popularity for other uses due to its nonreactive, nontoxic, and nonflammable properties, being effective at low temperatures without degrading the object's integrity. This is especially advantageous in applications like sterilizing medical devices and in the food industry.
