2. JOINTS AND WELDING JOINTS
TYPES OF WELDING JOINTS
AND APPLICATIONS
TERMINOLOGIES AND
SAFETY OF WELDING
GMAW
3. • An area at which two ends, surfaces and edges are attached.
• A point at which parts are joined.
• The manner in which materials fit together is termed as joint.
(American Welding Society)
Joints:
4. Welding joints
• To unite (metallic parts ) by
heating and allowing the
metal to flow together.
• The joint made by welding
are simply called welding
Joints.
5. Joints preparation
These techniques may include:
• Routing
• Stamping
• Shearing
• Casting
• Forging machining
• Filing
• Plasma arc cutting
• Oxy acetylene cutting and grinding
6. List of welding joints
According to American Welding Society, there
are 5 types of basic joints.
• Butt joint
• Lap joint
• Corner joint
• Edge joint
• T – joint
12. Types of grooves
• Grooves are used to increase the strength of
joint. Some of those grooves are as under:
• Single and double bevel
• Single and double V
• Single and double J
• Single and double U
13.
14. Butt joints
Types of butt joints:
• single welded
• Double welded
• Closed welded
• Open welded
15. applications
• A butt weld Pipe fitting:
a) it is designed to weld pipes together.
b) allow change in direction and diameter.
c) Use for transporting fluids oil, gas, steam
chemicals etc.
d) Efficient manner short or long distances.
16. • Flanges:
a) Flanges connect pipes by bolting them
together.
b) Whereas welded fittings are used to connect
pipes.
c) require 10% to 75% of less material than a
flanged connection.
d) Freedom in designing layout. Less space,
more compact and greater strength.
17.
18. • Valves:
a) Used on steel valves for size 50mm or above.
b) For higher temperature/pressure applications
in pipelines where frequent dismantling is
not required.
19. Advantages and disadvantages
Advantages
• Universally accepted method
• Easiest welding method
• Most common method
• Very affordable/cheap method
Disadvantages
• Chances of porosity in butt welds
• Edge preparation is required while working with
thick metal pieces
• cracking
20. corner joint
Types of corner joints
• flush corner
• Half open corner
• Full open corner
21. applications
• Used to attach sheet metal
• For welding light sheets close corner joint is
used
• For heavier metal sheets, half corner joint is
used
• Construction of boxes, box frames, etc
22. Advantages and disadvantages
• Advantages
• Strong welds can be produced
• Variety of Welds is possible i.e. thinner/thicker
• The most popular technique to join metal
sheets
• Disadvantages
• In a corner joint, there is a chance of
Increased Wear & Tear
23. Edge joint
• Advantages
• Useful for sheets less than 3mm thicker
• No preparation is required for this weld joint
• The filler material is not required.
• Disadvantages
• Weld doesn’t penetrate completely
• Can’t be used in stress & pressure applications
• Edge welds are not as common as other
• These joints are mostly replaced with other joints due
to build up accumulating on the edges
• Very rarely used joints technique
24. APPLICATIONS
• Parallel planes:
Use where edges of sheets are
adjacent and approx at parallel
planes
• Flanged joint:
use on flanging up edges. These
joints are used in automotive gas
tanks and housing.
• Aerospace:
use for aerospace repairing world.
25. LAP JOINT
• Types of joints
a) One sided lap joint
b) Two sided lap joint
26. applications
• Mostly used in resistance spot welding
• Gas tungsten arc welding
• Gas metal arc welding
• Not used for high energy welding
27. Advantages and disadvantages
Advantages
• not difficult technique
• No risk of blowing through the weld
• Lap joints are quicker & simple to be made
• Stronger welded joints are obtained
• Disadvantages
• Sheets bearing heavy loads can’t bear one-
sided lap weld
28. Tee joint
• Metal to be joined never lie on same plane
• Also considered as fillet joint
• Always making 90 degree angle
29. applications
Base attachment:
• When a metal piece is attached to some sort of base
Structural and machine work:
• It is used in structural and machine application
thin plates:
• a single beveled joint is used to weld finely on thin
plates from one sided welding
heavy plates:
• Double beveled joint is used in heavy plates which can
be welded from both sides.
30. Advantages and disadvantages
Advantages
• no preparation is needed in case of plain
tee joint.
Disadvantages
•Extra case is needed to ensure effective
penetration of the weld proof.
•Corrosion fatigue is common in tee welded
joints.
48. EAR PROTECTION
Noise – a combination of sound level and duration
of exposure, very high-level sounds are a hazard
even with short duration some of the examples of
hearing protection used in welding shop includes
Earplugs, earmuffs etc
49. HAND PROTECTION
Note
Avoid gloves when operating machines such as
bench drills where the gloves might get caught but
always them while doing welding
50. FOOT PROTECTION
•It provide protection against hot and cold
conditions, electrostatic build-up, slipping, cuts and
punctures, falling objects, heavy loads, metal and
chemical splash
•Safety boots and shoes with protective toecaps
and penetration-resistant, mid-sole wellington
boots and specific footwear, e.g foundry boots and
chainsaw boots
51.
52. DEFINITION:
Gas metal arc welding (GMAW) is a welding process
in which an electric arc forms between a
consumable wire electrode and the work piece
metal(s), which heats the work piece metal(s), causing
them to melt and join. Along with the wire electrode,
a shielding gas feeds through the welding gun, which
shields the process from contaminants in the air.
53. To perform gas metal arc welding, the basic necessary equipment is a
wire feed
unit
welding
gun
welding
electrode
wire
shielding
gas supply.
welding
power
supply
54. The typical GMAW welding gun has a number
of key parts
1. control switch
2. contact tip
3. power cable,
4. gas nozzle
5. electrode conduit
6. Liner
7. gas hose
55.
56. •Most applications of gas metal arc welding use a
constant voltage power supply.
•Alternating current is rarely used with GMAW;
instead, direct current is employed and the electrode
is generally positively charged.
57. The main function of the wire feed unit is to feed
the electrode wire, at a constant rate, to the
welding arc.
58. The electrode is a metallic alloy wire, called a MIG wire,
whose selection, alloy and size, is based primarily on
the composition of the metal being welded.
59. Shielding gases are necessary for gas
metal arc welding to protect the welding
area from atmospheric gases.
The choice of a shielding gas depends on
several factors, most importantly the
type of material being welded.
60. 1. Select a Filler Metal. ...
2. Set the Shielding Gas. ...
3. Understand the Weld Parameters.
4. Know Your Identify the Base Material.
5. Torch Angle. ...
6. Master Your Travel Speed. ...
7. Achieve Your Desired Bead Appearance,
Quality.
61. The type of material, thickness, and whether the
metal is coated are all important factors. These
properties will affect the weld, including machine
setup, filler metal type, shielding gas, and even
which welding process to use.
• Start by wiping the surface with a degreaser or solvent.
• Continue cleaning the material with a wire brush or grinder to
remove any surface contaminants
CLEANBASEMETALS :
62. Choosing the incorrect wire may
compromise the strength of your weld
The wire diameter you choose depends on
the thickness of the base material.
Depending on your application, certain gas
mixtures are more suitable than others. A
universally good mix for welding mild and
carbon steels is 90 percent argon/10 percent
CO2.
63. Before you set torch to metal, you need to set
other welding parameters, like wire feed speed
,torch angle and voltage.
64. Travel speed is key to successful welding and can be
tricky to master. Keep in mind that your amperage
settings determine your travel speed.
