Basics on Welding

Welding is a process of joining materials such asused for joining pipes and simple fabrication.
metals and plastics using heat or pressure. It is theArc welding uses an electrical arc between an
most popularly used method today to join metals,electrode and the subject material and at the same
and is used extensively in the production oftime melting them together to create a strong bond
automobiles, ships, trains, buildings, and bridges.or a weld. Arc welding is extensively used in industrial
Compared to soldering and brazing which introduce aapplications because it's economical. The problem with
soft melted substance to hold original piecesthe arc process is that sometimes welds can become
together, welding process melts the metals togetherbrittle and weak due to oxygen and nitrogen present
to form a robust and a strong join.in the atmosphere. To overcome this problem,
Welding had been practiced since ancient days. Theshielded gas such as hydrogen, argon and helium are
most popular method during this era was forgeused.
welding that was used by blacksmiths. This methodResistance welding uses physical pressure and heat
used to weld two metals by beating them togetherto weld materials. The heat is generated by the
over a hot coal.resistance of high electrical current passing through
Today, the modern technologies have allowedthe materials that have to be welded. This method is
welders to work with much greater precision andpopular among many industrial applications because it
achieve stronger welds compared to olden days. Theis easily automated and economical at high volumes
first World War gave the impetus for theof production. Due to its high initial investment cost it
development of welding technologies, as manymay not be feasible to use on low production
countries were looking for better and efficient waysvolumes.
of welding ships and planes for the war. From thereSpot welding is another form of resistance welding
onwards, welding technology developed into awhich is used to join four metal sheets. In spot
modern art which could be performed manually aswelding, two electrodes are used to weld metal
well as using robotic machines. In particular, it can besheets that are clamped together while applying
performed under different environmental conditionspressure and sending a high current through them.
such as underwater, on-site and in workshops. InSpot welding can be automated and it is energy
spite of these rapid advances, welding seems a highlyefficient, therefore it is extensively used in many
risky and a dangerous process which can expose aindustrial applications, such as automotive assemblies.
welder to burns, poisonous or toxic gases and evenElectron beam welding process uses high velocity
eye damage.electron beam on the materials. When high velocity
Most common methods of welding practiced todayelectrons bombard the materials, very high heat is
are gas, arc, spot, resistance, electron beam, laserproduced melting the materials and creating a strong
and robot welding.bonded joint. The electrons beam is produced by
Gas welding is commonly referred as Oxyacetyleneusing a hot cathode emitter made out of tungsten.
where gas and oxygen are mixed together toThis method is a very precise one, and used
produce a high temperature flame at the torch topopularly in aerospace and semiconductor industry.
melt the edges of metal that have to be welded.Laser beam welding process join multiple pieces of
Hence, Oxyacetylene welding usually requires twometal using a concentrated heat source. This method
tanks or bottles to store oxygen and the fuelis not only precise and but also efficient because of
acetylene. This method is one of the oldestvery little heat loss from the specific area. Also, the
techniques used and still practiced all over the world.laser is able to penetrate heat deep into the metals
This is mainly because the equipment includingwelded. Laser beam welding is used in automated
storage bottles are easily portable. This is extensivelyautomotive assembly plants.