Notes on Gas Welding

Introduction To Gas Welding:

Arc welding and Gas Welding are two major distinctions in Modern Welding Technology. Both of them have its own merits and demerits. Here we will discuss main things coming under Gas Welding Process like, main flame types, advantages, limitations, flux etc.

Types of Flames Used in the Gas Welding:

1. Neutral Flame.
2. Oxidizing Flame.
3. Carburizing Flame.

1. Neutral Flame:

• As name suggests, it is neutral in nature. Neither oxidizing nor else.
• Neutral Flame is achieved by keeping Oxygen and Acetylene in equal proportions.
• The temperature of this flame goes up to 3200 degree Celsius.
• Inner cone of Neutral Flame is clearly defined, seen.

2. Oxidizing Flame:

• Oxidizing flame needs more amount of Oxygen than that of Acetylene.
• This flame burns this roar sound.
• This flame also have temperature range up to 3200 degree Celsius.
• Generally, this flame is used for cutting purpose.

3. Carburizing Flame:

• Opposite to Oxidizing flame, carburizing needs more amount of Acetylene than Oxygen.
• Temperature goes up to 3000 degree Celsius.

Advantages of Gas Welding:

• Gas welding process finds enormous applications in the various industries due to its versatility.
• Unlike arc welding, actual site of welding is visible. This provides considerable control on the welding process.
• Temperature of the process can be easily controlled by changing the volumes of input fuel gases.
• This is comparatively low-cost process than most of the arc welding processes.
• One of the most important advantage of Gas Welding over Arc Welding is: Gas welding apparatus is portable and Electric Supply is not needed.

Limitations of Gas Welding:

• Heavy sections can not be joined with Gas Welding.
• Flame temperature is lower than other Arc welding processes like TIG welding, MIG Welding etc.
• Welding speed is lower due to low flame temperature.
• Flames formed due to burning of gases are dangerous to human eyes and throat.
• Combustible gases are needed to be carried in the cylinders which is dangerous.
• Gases are expensive.
• Refractory materials can not be welded.
• Unlike some arc welding processes it can not be automated.

Why Flux Is Used in the Welding Process?

Welding is the process in which metal is heated so high that it melts. This molten mass of metal comes in contact with the Oxygen in the air. Oxygen readily combines with most of the metals to for the metal oxide or oxide of that metal. As we know, oxides are very hard and hardness brings brittleness with it. This results into welded output with low strength. To avoid this phenomenon, Flux is used in welding processes.

Importance of Flux:

• Flux prevents oxidation of molten metal.
• Flux dissolves and forms slag which covers the actual FLAME or coalescence which keeps atmospheric gases and oxygen away.
• Flux is available in various forms viz. powder, paste, liquids, gas etc.
• Some examples of flux are: sodium chloride, boric acid, soda ash, borax, lithium chloride, magnesium silicate etc.

About Topic:

This part, Gas Welding, comes under Mechanical Engineering, Production Engineering and Manufacturing Processes.