General Knowledge - General Science - Discussion

A weld is done so it stays welded and intact without undergoing oxidation, leading to failure. Therefore a protective coating of inert gas (which is usually CO2 or Argon) is used, INEVITABLY, or else the welding is either underwater or in a vacuum. Hence, I Believe [C] should be the right answer.

But on the other hand, argon welding is contain argon gas.

No, the Correct answer is "c".

I think that when oxygen and acetylene are proper to welding than why to add extra argon gas, it's costly.

No, D is the right answer.

Oxygen react with acetylne and forms diff types of flame which is at very high temp.

Because oxygen reacts with acetylene in presence high temperature and it helps easy to welding.

Carbon dioxide, Argon and helium gases are also used in welding. They act as shielding gases and prevent oxidation of the molten pool.

Oxy-fuel welding (commonly called oxyacetylene welding, oxy welding, or gas welding in the U.S.) and oxy-fuel cutting are processes that use fuel gases and oxygen to weld and cut metals, respectively. French engineers Edmond Fouché and Charles Picard became the first to develop oxygen-acetylene welding in 1903. Pure oxygen, instead of air (20% oxygen/80% nitrogen), is used to increase the flame temperature to allow localized melting of the workpiece material (e.g. steel) in a room environment. A common propane/air flame burns at about 3,630 °F (2,000 °C), a propane/oxygen flame burns at about 4,530 °F (2,500 °C), and an acetylene/oxygen flame burns at about 6,330 °F (3,500 °C).

O2 + C2H2---> Oxyacetylene gas and very hot temperature. this temperature helps to welding.