Dheeraj sajja - RA2011026010164
ELECTICAL ARC WELDING
BUTT JOINT
PREPARATION
TACK WELD
FINAL WELD
All Dimensions are in mm (100 x 30 x 6)
1
ELECTRICAL ARC WELDING
BUTT JOINT
Ex no: 1a
Date: 28/4/21
Aim:
To make a butt joint of given two mild steel plate of size 100 x 30 x 6 mm using arc
welding method.
Application:
Butt joint is used in very heavy structures, constructions, and steel furniture using arc
welding.
Material Specification:
Mild steel plates of dimension 100mm x 30mm x 6mm – Two pieces
Tools Required:
1) Bench vice 2) Try square 3) Steel rule 4) Flat File 5)
Chipping hammer 6) Wire brush 7) Tongs 8) Welding shield.
Equipment Required:
1) Electrical arc welding machine 2) Arc welding cable 3) Ground clamp
Safety Equipment’s:
1) Leather apron 2) Hand gloves 3) Goggle etc.
Sequence of Operation:
2
1) Preparing 2) Tack welding 3) Final welding 4) Chipping & Cleaning.
Working Steps:
1) Preparing:
a) Clean the edges of the work piece using wire brush to remove dust and rust.
b) Check the dimensions using steel rule and also check the straightness of the edges
to be joined using try square.
c) File those edges using flat file, make them straight and check with the try square.
2) Tack welding:
a) Place the pieces as close as possible butting against each other over welding table
b) Check the welding machine, cable, electrode and clamp for proper connection
c) Select correct electrode (3.15mm) and fix it in electrode holder, use gloves while
fixing the electrode
d) Switch on welding machine, adjust the current to 100amps. Keep the shield closer
to eyes and move the electrode nearer to one end of the work piece pair. Electrode
should not touch the work piece. A critical distance should be maintained to produce
spark. Make a spot over the work piece.
e) The same way make another spot at the next end of the work piece pair. This is to
keep the pieces in place during welding.
3) Final welding:
a) Move the electrode to first tack and make a spark
b) Gradually move the electrode towards the second tack without shaking the electrode
and maintain the gap between electrode tip and work piece.
c) This is called as first run (Back hand welding id preferred for thick plates)
d) For the second run start from first tack and move towards second tack with uniform
oscillation motion. This keeps the metal molten a little longer and allows the slag to
the surface.
4) Chipping and cleaning:
a) Allow the work piece to cool and dip it in the water using tongs.
b) With the help of chipping hammer gently tap the weld bead so that the slag coating
Is remove from the work pieces?
c) Clean the work piece with wire brush thoroughly.
d) Check for the dimensions
3
Pre-Lab Question:
1. What is mean by welding?
Welding is a fabrication process whereby two or more parts are fused
together by means of heat, pressure or both forming a join as the parts cool.
Welding is usually used on metals and thermoplastics but can also be used on
wood.
2. Name of the two important welding process?
These include metal inert gas (MIG) welding, stick welding, tungsten inert gas
(TIG) welding also known as gas tungsten arc welding (GTAW), gas welding, metal active
gas (MAG) welding, flux cored arc welding (FCAW), gas metal arc welding (GMAW),
submerged arc welding (SAW), shielded metal arc welding (SMAW) and plasma
3. How many types of arc are there?
Arc welding, including gas shielded arc welding, is broadly divided into
two types: consumable (fusible) electrode type and non-consumable (non-
fusible) electrode type depending on whether the welding rod/wire melts in the
process or not.
4. Mention the other name for fusion welding?
The fusion welding process is also known as Induction welding
5. Arc welding is also known as?
Shielded Metal Arc Welding (SMAW)
Post Lab Question :
1. What is arc welding?
4
Arc welding is a type of welding process using an electric arc to create
heat to melt and join metals. A power supply creates an electric arc between a
consumable or non-consumable electrode and the base material using either
direct (DC) or alternating (AC) currents.
2. Which of the following is a measuring tool?
Common measuring and leveling tools for welders include the framing
square, carpenter's square, cabinet maker's square, combination square, torpedo
level and builder's level.
3. What purpose the bench vice is used for?
A bench vise is a mechanical apparatus used to secure an object that is
to be worked on. It features two parallel jaws as part of the design. The device
is widely used in the mechanical and woodworking ind ustries, among others.
4. In arc blow, the deflection of the arc is?
Magnetic arc blow, also known as arc wander, is the arc deflection caused
by distortion of the of the magnetic field produced by an electric arc current.
5. In plasma arc welding, the gas is?
The gas used in plasma arc welding is Argon for the plasma gas with
argon plus 2% to 5% Hydrogen for shielding gas .
Result:
Thus, the given two plates are joined by butt joint using arc welding method
