Comparison between AC welding and DC welding

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

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

AC welding and DC welding are basically two different types of arc welding that use different currents in order to develop an electric arc. Such types of welding involve the production of an electric arc between an electrode and the metal being welded.

The electric arc will provide the heat in order to fuse the metals together. A power supply will be used to create the arc, which can either use direct current (DC) or an alternating current (AC).

The selection of power source i.e. Direct current or Alternating current will decide the polarity of the electrical current that runs through the electrode. The source of power which is used will also impact the weld developed. 

Salient Features of AC Welding 

1. It is not suitable for welding non-ferrous metals 

2. Maintenance cost is less 

3. It is cheaper and simple welding 

4. It is not suitable for welding sheet metals, since starting the arc is difficult 

5. It consumes less power and also produces less noise 

6. Bare electrodes cannot be used 

7. AC is more dangerous 

8. Arc is never stable 

9. It can be used at a large distance from the power supply due to less voltage drop 

Salient Features of DC welding 

1. It is suitable for welding both ferrous and nonferrous metals 

2. Maintenance cost is high 

3. It is costlier and complicated 

4. It is suitable for all types of weld as starting the arc is easy 

5. It consumes more power and also produces

6. more noise 

7. Both coated and bare electrodes can be used 

8. DC is comparatively less dangerous 

9. Arc is stable 

10. It can be used only at a short distance from the power supply since the voltage drop is higher

We will see the soldering and brazing process in our next post. 

Reference 

Engineering Practices by Mr. S. SUYAMBAZHAHAN