In electric arc welding is only a electrical spark, otherwise it is nothing. It is
fusion welding process. It is work in a closed electrical circuit in which current
flows. If a small gap formed in the circuit then there an electrical spark is occurred,
which is called electrical arc. In this spark or arc are contain a huge amount of
temperature like 34000C-40000C. Due to this huge temperature, the weld metal can
be fuse in arc welding process.
Principle of Arc welding
In the arc welding the heat is produced through an electrode or arc welding rods.
The electric arc is produced between consumable electrode and the work piece. The
current is continuously supplied through the consumable electrode and fillet deposited
on work piece. Thus the electric arc welding process is carried out. The electrode
which is passing the current is made with flux coated, these types of electrode is
called bar electrode. The coating flux are melt at the time of welding and deposited
upper level of filler metal as a slag, which is removed by chipping or grinding process
after normal cooling. The filler metal is called electrode in arc welding practice.
The carbon-arc welding is the another type of arc welding. Where carbon or graphite
are used as a electrode. There are two methods used for produced an arcs, the single-carbon
process and another is the twin-carbon process. The main difference is, the twin-carbon
arc welding carried electrically independent torch. The carbon-arc welding is invariably
carried out with direct current. The heat is produced between carbon electrode and
work piece, base metal melts with this heat and additional filler metal can be added
where extra metal needed. The essential point of this carbon-arc welding is that
the filler rod quite difference from the ordinary filler rod. Because it can not
be connected with current source.
Work piece distortion is less.
Process is suitable for any kind of joint.
Weld heat can be controlled very easily through changing of arc length.