Contents
1.0 INTRODUCTION..
2
2.0 OBJECTIVES. 3
3.0 SAFETY IN THE
WORKSHOP. 3
3.1 Personal
Protection. 3
3.2 Safety Precaution.
3
4.0 Material and
Tools. 4
5.0 TYPES OF WELDING
JOINT. 9
5.1 Patent-Pending
Process. 9
5.2 Close Butt Joints.
10
5.3 Corner Joints.
12
6.0 SUGGESTIONS FOR
IMPROVEMENT. 13
7.0 CONCLUSION..
14
1.0 INTRODUCTION
- Arc welding is a type of welding that uses a
welding power supply to create an electric arc between an electrode
and the base material to melt the metals at the welding point. They
can use either direct (DC) or alternating (AC) current, and
consumable or non-consumable electrodes. The welding region is
usually protected by some type of shielding gas, vapor, or slag.
Arc welding processes may be manual, semi-automatic, or fully
automated. First developed in the late part of the 19th century,
arc welding became commercially important in shipbuilding during
the Second World War. Today it remains an important process for the
fabrication of steel structures and vehicles.
- Arc welding is one of alternative for joining process in
manufacturing. Arc welding process had done by create an electric
arc between electrode and the base material to melt the metal at
the welding point using welding power supply. The welding region is
sometimes protected by some type of inert or semi-inert gas, known
as a shielding gas and sometime adds by an evaporating filler
material. Shielded metal arc welding (SMAW), also known as manual
metal arc (MMA) welding or informally as stick welding, is a manual
arc welding process that uses a consumable electrode coated in flux
to lay the weld. They can use either direct current (DC) or
alternating current (AC) from a welding power supply, used to form
an electric arc between the electrode and the metal to be joined.
As the weld is laid, the flux coating of the electrode
disintegrates, giving off vapors that serve as a shielding gas and
providing a layer of slag, both of which protect the weld area from
atmospheric contamination. Gas metal arc welding (GMAW), sometimes
referred to by its sub types metal inert gas (MIG) welding or metal
active gas (MAG) welding, is a semi-automatic or automatic arc
welding process in which a continuous and consumable wire electrode
and a shielding gas are fed through a welding gun. A constant
voltage, direct current power source is most commonly used with
GMAW, but constant current systems, as well as alternating current,
can be used. There are four primary methods of metal transfer in
GMAW, called globular, short-circuiting, spray, and pulsed-spray,
each of which
2.0 OBJECTIVES
At the end of this arc welding
learning, student should be able to:
- Provide a brief introduction to engineering students about
metal arc welding.
- Learn the basic techniques of welding.
- Give a real life experience of metal arc welding to engineering
students.
3.0 SAFETY IN THE WORKSHOP
3.1 Personal
Protection
- Wear Approved Eye Protection
- Wear Flame Resistant Clothing
- Wear Long Sleeves, Pocket Flaps and No Cuffs
- Wear Approved safety boot
- Wear Approved Hand Protection
3.2 Safety
Precaution
- Please wear all the personal protective equipment recommended
by OSHA.
- Always protect your eyes from arc rays.
- Protect your face and body from heat radiation and molten
metal.
- Move all the flammable material off the working place or cover
it up using fireproof material.
- Make sure that the welding machine is earthen.
- Make sure that all line holder, earth clip and connection
placed on good place.
- Make sure that your working place is clean and tidy.
- Make sure that all electric connection is tight, clean and
dry.
- Avoid pulling the cable on top or near sharp things.
- Do not ever scratch arc on top of gas cylinder.
- Turn off the welding machine when not in use.
- Avoid welding cable from be in contact with hot metal, water,
oil and grease.
- Wear all safety clothing when welding.
- All equipment such as hammer, chisel, brush and others must be
well maintained.
- A welder should not try to install or repair a welding machine.
has distinct properties and corresponding advantages and
limitations.
4.0 Material and Tools
4.1
Mild steel flat bar (6 x 40 x 100 mm)
4.2
Electrode
- Electrode that use is E4113/ E6013
- The "E" stands for arc welding electrode. Next will be either a
4 or 5 digit number stamped on the electrode. The first two numbers
of a 4 digit number and the first 3 digits of a 5 digit number
indicate the minimum tensile strength (in thousands of pounds per
square inch) of the weld that the rod will produce, stress
relieved. E6013 electrode can be used with AC and DC currents. It
produces a medium penetrating weld with a superior weld bead
appearance.
4.3 DC Arc Welding
Machine
4.4 Face Shield
- It is made from inflammable material. In the middle of the
shield there is a bright rectangular glass coated with dark colored
glass. It is used to protect the user from fire-bolt and harmful
rays during welding work. There are two types of shield, one is the
helmet type and the other one is the hand held type.
4.5
Leather Hand Gloves
- It must be made from high quality leather. Use to protect your
hand from fire-bolt and hot metal welding.
4.6
Plier
- Used for hold hot workpiece
4.7
Chipping Hammer
- It is made from an old punch, chisel or spring metal.
- Shape like a chisel at one end and has a sharpened end at the
other one.
- Its holder is made from welded soft metal.
- It is used commonly to remove the slag excess stringer from the
surface of the work metal.
4.8
Wire Brush
- Used to clean the surface of the stringer bed after the slag is
chipped away and to remove dirt from the surface of metal work
before welding can be done.
4.9
Leather Jacket
- Leather jacket is used to protect the user from the intense
heat produced during welding operations.
- It is made of high quality leather to provide greater comfort
for the user.
4.10 Angular Mild
Steel Bar
- Used for hold two pieces of metal during corner joint
weld.
5.0 TYPES OF WELDING JOINT
5.1 Patent-Pending
Process
- Clean the surface of metal plate with wire brush.
- Place the metal plate on the working table.
- Before welding, adjust the electric current to DC current and
scratch the electrode on the scrap metal.
- Hold the electrode about 90o above the scrap metal.
Tilt the electrode 30o to the left or right depending on
which hand do you use from the work metal.
- Scratch the front end of the electrode onto the work metal to
start the burning. After the electrode has started burning, hold it
at 3mm above the work metal. Try to avoid the electrode from being
in contact with the surface of work because the electrode might be
stick onto the workpiece.
- Repeat the welding process for several times until you get a
straight stringer bead line when welding.
- Repeat the process of (f) for second straight stringer bead
line.
- When finish the welding process, use the chipping hammer to
chipped off the slag and brush it off using a wire brush
5.2 Close Butt
Joints
- Clean the surface of two (2) metal plates with wire brush.
- Place both metal plates on the working table.
- Before welding, adjust the electric current to DC current and
scratch the electrode on the scrap metal.
- Hold the electrode about 90o above the scrap metal.
Tilt the electrode 30o to the left or right depending on
which hand do you use from the work metal.
- Make tack weld on both side to prevent the metal plates from
bending during the welding process occur.
- Scratch the front end of the electrode onto the work metal to
start the burning. After the electrode has started burning, hold it
at 3mm above the work metal. Try to avoid the electrode from being
in contact with the surface of work because the electrode might be
stick onto the workpiece.
- When finish the welding process, use the chipping hammer to
chipped off the slag and brush it off using a wire brush
5.3 Corner Joints
- Clean the surface of two (2) metal plates with wire brush.
- Place the angular of mild steel on the working table to support
two (2) metal plates.
- Before welding, adjust the electric current to DC current and
scratch the electrode on the scrap metal.
- Hold the electrode about 90o above the scrap metal.
Tilt the electrode 30o to the left or right depending on
which hand do you use from the work metal.
- Make tack weld on both inside the metal plates to prevent the
metal plates from not parallel during the welding process
occur.
- Scratch the front end of the electrode onto the work metal to
start the burning. After the electrode has started burning, hold it
at 3mm above the work metal. Try to avoid the electrode from being
in contact with the surface of work because the electrode might be
stick onto the workpiece
- When finish the welding process, use the chipping hammer to
chipped off the slag and brush it off using a wire brush
6.0 SUGGESTIONS FOR IMPROVEMENT
- Changes all leather gloves which not in good condition.
- Use a suitable exhaust fan during welding
- Change the cable that connected to the earth holder and
electrode holder which not in good condition
- Make sure the mirror of the face shield clearly.
7.0 CONCLUSION
In conclusion, we can conclude that there are some problems that
happened in arc welding process.
The first problem that happened in arc welding process is the
thicknesses of arc line on metal plate. We can overcome it such as
we can improve our skill with we can reduce the movement of speed
when doing arc welding.
Second problem is combination of the metal plate is not too
strong. It may cause the work be crack or don’t have enough
quality. To overcome this problem is we need to add more electrodes
at the work.
Third problem is the work of arc welding not good enough. It may
cause from the wrong angle and wrong position on plate when doing
welding. This problem can solve if we use 30º in angle and at least
3mm between electrode and plate when welding.
After we make some work of welding, we can know the main factor why
the work in our welding is not too good. The main factor is lack of
skill from student. So that we need to improve ourselves by do the
weld properly and use the right method in welding.