Electric arc welding

In this article we will discussed about the electric arc welding . we will discussed different type of material which are used in electric arc welding.

Electric arc welding is that processes in which the pieces of the metal to be welded the pieces of the metal to be welded are brought to the proper welding temperature at point of contact by the heat liberated at the arc terminals and in the arc stream so that the metals are completely fused into each other forming a single solid homogeneous mass after it solidifies. In this processes an electric arc is produced by bringing two conductors (electrode and metal piece) conducted to suitable source of electric current momently in contact and then separating by a small distance. The current continuous to flow across the small gap and gives intense heat. The heat developed is utilized to melt a part of the work piece and the filer metal and thus from the joint. The heat developed by arc is also used for cutting of metal.

There are electric arc welding is divided in two part

1. Bare metal electric Arc welding

 2. Shielded metal welding

In this type of welding a metal rod of the same metal as being welded from one of the electrode and also serves as filler a no filler rod is used separately. The arc strut between the work being welded and the electrode cause the melted rod to flow across the arc into the metal pool of the parent metal. This deposition of metal is accomplished by contact made between the molten metal and the global formed on the end of the electrode causes a small part of the work being welded to melt almost instantaneously and end intermittent flow of metal across the arc stream.

The metal in the arc system is in both the liquid and gaseous form the liquid metal being transferred across the by molecule are attraction, adhesion, cohesion, surface tans an or combination of piece.

For this type of welding both AC and DC can be used. For DC supply 50 to 60 volt and AC supply 70 to 100 volt are used for welding.

For current above 750Amp

AC equipment is preferred as it has high efficiency, negligible loss at no load and minimum maintained and initial cost.

In this type electric arc welding carbon material are used for welding. Carbon metal have some additional properties which cause it is used in electric arc welding.

Advantage of cordon electrode

The main advantage of carbon material in electric arc welding

The carbon is is very stable and easy to maintain. The length of arc can be varied over wide limits without causing the arc to go out. Carbon arc welding have a high melting speed and efficient welds are the main advantage.

Process of electric arc welding

In this process a cordon or graphite rod is used as negative electrode and the works being welded as a positive. Mostly graphite electrode is used as they yield. Longer life and have low resistance and thus capable of conducting more current. The arc produced between two electrodes; heat the metal to the melting temperature this is above 3200 degree on the negative electrode.  Negative electrode and 3900 degree on the positive electrode.

The reason the use of carbon rod  as negative electrode is that  will be generated at the electrode tip then that at the work piece and carbon from the electrode will  not fuse and mix up with the job . if this so happen the resultant weld will be rich in carbon and consequently very much brittle and  up sound this type of welding only dc can be used. The use of AC is not recommended because not fixed polarity can be maintained.

Carbon arc welding is employed for welding steal brass, Bronze and aluminum.

Demerit of carbon material in electric arc welding

It is not suitable for vertical and overhead welding

Hence it is the main type of electric arc welding and their working if you will find any incorrect above article please comment below.

For knowing more about electric arc welding you must watch this video.