Difference Between Arc welding and Gas welding

We have seen the overview of a welding process, Arc welding process, Gas welding process and types of flames in Gas welding with the help of our previous posts.

Let us get more in depth and understand now the difference between Arc welding and Gas welding with the help of this post.

Arc Welding 

In the arc welding process, the welding temperature is produced by an electric arc, established between an electrode and the metal being welded. The temperature of the arc is 7000 degrees Celsius. 

Salient Features of Arc Welding

1. Electrode acts as a filler rod 
2. Electric arc is the source of heat 
3. Brazing soldering cannot be done using electric arc 
4. The arc temperature is about 7000 degree Celsius 
5. It has high strength 
6. This is a non-pressure fusion welding method 
7. Risk due to electric shock 
8. Filler metal should be an alloy of parent

Gas Welding 

Gas welding process is basically a fusion welding process. It joints metals using the heat of combustion of an oxygen/air and fuel/gas (acetylene, hydrogen, butane) mixture. The flame thus melts and fuses together the edges of the parts to be welded, with the addition of a filler metal. The oxyacetylene gas welding is commonly used in practice. 

Oxy-acetylene is used to weld almost all metals and alloys. Acetylene is mixed with oxygen in correct proportions in the welding torch and ignition. The flame resulting at the tip of the torch is sufficiently hot to melt and join the parent metal. The flame reaches a temperature of about 3000 degree Celsius.

Salient Features of Gas welding 

1. Separate filler rod is supplied 
2. Gas is the source of heat 
3. Brazing and soldering can be done by gas 
4. The gas temperature is about 3000 degree Celsius  
5. Comparatively less strength 
6. This is also a non-pressure fusion welding method 
7. Risk due to gas pressure 
8. Filler metal need not be the same as parent metal 

We will see the difference between AC welding and DC welding in our next post. 

Reference 

Engineering Practices by Mr. S. SUYAMBAZHAHAN