Unit 23 Producing Quality Welded Joints Assignment 3
For this assignment I will discuss the advantages & disadvantages of two welding processes
considering consumables, equipment, technique & quality for a given welding application.
Beginning with Gas Welding, this method mainly focuses on high temperature flames that are
produced by gas combustion, which is used to melt the work pieces together. In gas welding, there are
a few pros & cons, required to make sure that they take into account when choosing a method of
welding.
There is no requirement for refined & costly equipment as well as an additional source of electricity;
therefore, welding is very much possible in the open field. Just for added information, the majority of
the pipelines that were created between 1926 & 1935 were in fact gas welded, & this feature allows
the welder to carry out repair works in numerous parts of buildings, areas etc.
A welder can with ease vary the temperature of the flame, & when the welder changes the angle of the
flame to the surface to be welded, the temperature differs; to achieve the highest temperature, the
flame must be on a perpendicular to the object. Furthermore, the power gathered when gas welding
joins will mostly likely be larger than in arc welder using low quality electrodes.
Not only can gas welding allow for welding, cutting & tempering metals, but it can greatly vary the
power flame when welding metals with different melting points; & it can also slowly heat & cool the
welded surfaces.
Whilst there are many advantages of gas welding, there are also a lot of cons that come with it. Gas
welding has a very low welding speed, meaning that it’ll most likely lead to a wide build-up of weld;
also, the shape of the weld will not be consistent due to the fact that the weld pool has built up & then
fallen in the crater, which can further lead to weak joints & slag.
Low power density is the next con as this’ll lead to a tall, very narrow bead that has a weak
penetration to the metal. Likewise, it’ll be problematic when starting the weld & the arc is prone to
drifting towards one side of a joint in favourite to the other.
Additionally, there are heat affected zones (HAZ), which is essentially the area of base material,
(usually metal in this) that isn’t properly melted & has had its microstructure & properties changed.
Moving onto MIG welding as my second welding application; MIG welding is endured with a
handheld gun as a semiautomatic process; this process can be suited to a range of job needs by
selecting the appropriate shielding gas, electrode size & welding parameters (parameters are: voltage,
speed, arc length, rate of wire being fed). This application links the pros of stability, speed,
proportional freedom from alteration & the dependability of automatic welding with the flexibility &
control of manual welding.
The pros & cons of MIG welding are characteristically determined by the kind of MIG welder & the
nature of the job. High productivity would be the first advantage of this welding method as the many
welders will appreciate higher productivity due to time saved by not having to regularly change rods
or chip away slag as well as not having to brush the weld continually, which means that they are able
to work faster & cleaner.
One of the most beneficial advantages is of how simple MIG welding is as welders can easily learn
how to MIG weld within a very short time period. Likewise, MIG offers a better visibility of the weld
pool, making welding even more easier compared to other methods of welding.
Since MIG welding uses a shielding gas to protect the arc, there is little loss of alloying elements as
the metal transfers across the arc. There is no slag to remove, which is typical for stick welding, &
only minor weld spatter is produced.
M2 Fahim Mohammed
For this assignment I will discuss the advantages & disadvantages of two welding processes
considering consumables, equipment, technique & quality for a given welding application.
Beginning with Gas Welding, this method mainly focuses on high temperature flames that are
produced by gas combustion, which is used to melt the work pieces together. In gas welding, there are
a few pros & cons, required to make sure that they take into account when choosing a method of
welding.
There is no requirement for refined & costly equipment as well as an additional source of electricity;
therefore, welding is very much possible in the open field. Just for added information, the majority of
the pipelines that were created between 1926 & 1935 were in fact gas welded, & this feature allows
the welder to carry out repair works in numerous parts of buildings, areas etc.
A welder can with ease vary the temperature of the flame, & when the welder changes the angle of the
flame to the surface to be welded, the temperature differs; to achieve the highest temperature, the
flame must be on a perpendicular to the object. Furthermore, the power gathered when gas welding
joins will mostly likely be larger than in arc welder using low quality electrodes.
Not only can gas welding allow for welding, cutting & tempering metals, but it can greatly vary the
power flame when welding metals with different melting points; & it can also slowly heat & cool the
welded surfaces.
Whilst there are many advantages of gas welding, there are also a lot of cons that come with it. Gas
welding has a very low welding speed, meaning that it’ll most likely lead to a wide build-up of weld;
also, the shape of the weld will not be consistent due to the fact that the weld pool has built up & then
fallen in the crater, which can further lead to weak joints & slag.
Low power density is the next con as this’ll lead to a tall, very narrow bead that has a weak
penetration to the metal. Likewise, it’ll be problematic when starting the weld & the arc is prone to
drifting towards one side of a joint in favourite to the other.
Additionally, there are heat affected zones (HAZ), which is essentially the area of base material,
(usually metal in this) that isn’t properly melted & has had its microstructure & properties changed.
Moving onto MIG welding as my second welding application; MIG welding is endured with a
handheld gun as a semiautomatic process; this process can be suited to a range of job needs by
selecting the appropriate shielding gas, electrode size & welding parameters (parameters are: voltage,
speed, arc length, rate of wire being fed). This application links the pros of stability, speed,
proportional freedom from alteration & the dependability of automatic welding with the flexibility &
control of manual welding.
The pros & cons of MIG welding are characteristically determined by the kind of MIG welder & the
nature of the job. High productivity would be the first advantage of this welding method as the many
welders will appreciate higher productivity due to time saved by not having to regularly change rods
or chip away slag as well as not having to brush the weld continually, which means that they are able
to work faster & cleaner.
One of the most beneficial advantages is of how simple MIG welding is as welders can easily learn
how to MIG weld within a very short time period. Likewise, MIG offers a better visibility of the weld
pool, making welding even more easier compared to other methods of welding.
Since MIG welding uses a shielding gas to protect the arc, there is little loss of alloying elements as
the metal transfers across the arc. There is no slag to remove, which is typical for stick welding, &
only minor weld spatter is produced.
M2 Fahim Mohammed
