23/12/2022

Electrical Welding Questions & Answers-2

Important Question in Electrical Welding

In this post, some of important questions of electrical welding is discussed which include advantages and disadvantages of seam welding, application of seam welding, projection welding, meaning of platens, applications of projection welding, percussion welding, upset butt welding and non-pressure welding.

Advantages and Disadvantages of Seam Welding

Describe the advantages and disadvantages of the seam welding.

Advantages of seam welding

  • Efficient energy use
  • As the filler material is not necessary therefore no fumes or gases generated.
  • Two work pieces are joined by simply roll welding
  • Gas tight and liquid tight joint is done by stitch welding

Disadvantages of seam welding

  • Complex control circuit
  • If the metal thickness greater than 3 mm, it is difficult to weld
  • Higher current requires as compared to spot welding

Applications of Seam Welding

State the applications of the seam welding.

Applications

  • Metal can be welded except copper and its alloy
  • Welding of transformers, condensers, evaporators
  • Fabricate gas or liquid tight metal tank
  • Production of seam welded pipes

Describe the main difference between projection welding and spot welding.

Projection welding

  • There is high mechanical pressure applied on the metal pieces to be welded after the formation of the weld.

Spot welding

  • No mechanical pressure applied

Platens

What are platens?    

Platens

  • It is flat metal plates used as electrode in the projection welding.

Projection welding

State the applications of the projection welding.        

Applications

  • Mass production work
  • Punching
  • Welding of condensers
  • Welding of refrigerators

Types of butt welding

Describe the different types of butt welding.      

Types of butt welding

  • Upset butt welding
  • Flash butt welding
  • Percussion butt welding

How the upset butt welding is done?

  • The upset butt welding is done by joining metal parts end to end across secondary winding of the transformer.

Upset butt welding

State the application of the upset butt welding. 

Applications

  • Welding of metal end to end parts
  • Welding of rods
  • Welding of pipes
  • Welding of wires

Describe the advantages of flash butt welding over upset butt welding.

Advantages of flash butt welding

  • Low power requires
  • Clean weld due to burning of foreign metals on the surfaces by arc.

Percussion Welding

On which principle the Percussion welding is done? 

Percussion welding

  • The percussion welding is done by using magnetic energy storage or capacitor energy storage principle.

State the applications of the Percussion welding.       

Applications of Percussion welding

  • Welding of dissimilar metals
  • Welding of nickel alloy, aluminium alloy, copper alloy is done
  • Welding of silver contact tips to copper

On which factors the welding operation depends?

  • The welding operation depends upon welding pressure, welding current and welding time.

Describe the effect of welding current on the welding time?

  • Lesser the welding current, higher the welding time and vice versa

Describe the disadvantages of longer welding time.   

  • The longer welding time produces stronger weld but it produces distortion of the work piece and it consumes higher energy.

Non-pressure welding

Which type of welding is known as non – pressure welding? Why?

Electrical arc welding

  • The electrical arc welding is known as non – pressure welding because the mechanical pressure is not necessary in this welding.


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