Welding procedures and training for welding

1. WELDING TECHNIQUE

2. General Welding Concept
Welding Types
Safety/PPEs
Welding Tools
Materials
Welding Procedures Specifications (WPS)
Welding of Different Materials
Online Welding
COURSE CONTENTS

3. • General Welding Concepts
• Welding Safety
DAY 1
• Welding Types
• Practical
DAY 2
• Welding Tools
• Workshop Visit
DAY 3
• Materials
• Welding in TTC
DAY 4
• Welding Procedures
• Stripper Shop Visit
DAY 5
• Practical Demonstration of SMAW and GTAW
DAY 6
• Welding of Different Materials
DAY 7
• Online Welding
DAY 8
COURSE SCHEDULE

4. • First welding process was discovered about
5800 years ago by a blacksmith Tubal-Cain.
This was forged welding technique.
• In 1800, Frenchman Volta used bank of
batteries to produce an electric arc. But it was
unsuccessful.
• In 1865, Englishman Wilde was able to
generate electric arc and welded small pieces
of iron together.
WELDING-General Concepts
BRIEF HISTORY

5. • In 1890, Baltic Shipyards used bare electrode
first time for welding. But oxygen and other
gases contamination produced exceedingly
poor weld.
• In 1902, Swedish engineer Oscar Kjelberg
devised a method of shielding molten weld
metal. He used coated electrodes for the first
time and set a foundation of welding
technique which is still in use.
BRIEF HISTORY
WELDING-General Concepts

6. • When two pieces of similar or different
materials are joined together with the help
of high temperature with or without filler
material; This can be achieved either by
applying pressure or without it.
This process is known as WELDING.
WELDING-General Concepts
WELDING DEFINITION

7. • When two metals, which are not melted, are
joined with a third metal, which has a melting
point less than adjoining metals.
• Filler Metal: Eutectic Alloy, Tin Lead,
Tin-zinc etc.
WELDING-General Concepts
SOLDERING
APPLICATIONS
• Plumbing
• Electronics
• Jewelry Manufacturing

8. • When two metals, which are not melted, are
joined with a third metal, which has a melting
point less than adjoining metals.
• Filler Metals: AL-718, CP 102, High
Temp 080 etc.
WELDING-General Concepts
BRAZING
APPLICATIONS
• Automotive industry
• HVAC Equipments

9. • Soldering filler wire melting temperature is
less than 450°C whereas brazing filler
wire’s is above 450°C.
WELDING-General Concepts
DIFFERENCE BETWEEN
BRAZING & SOLDERING
Filler Wire Melting Point
SOLDERING
Tin-Lead 215°C
Tin-Zinc 343°C
BRAZING
High Temp 080 855°C

10. • The process of producing hole or cavity in
a metal piece by using electric arc is called
gouging.
WELDING-General Concepts
GOUGING
•Process is similar to
welding but instead
of conventional filler
metal a high carbon
electrode is used to
remove metal.

11. • Hand Held Screens
•Adjustable Helmets
• Clothing should be free from oil, grease or any
flammable substance.
• Do not roll up sleeves.
• Cuffs, turn-ups on trousers, exposed long hairs
and low cut shoes are places vulnerable for
sparks, slag or globules of hot metal etc.
WELDING PPEs
SCREENING
CLOTHING

12. SCREENING

13. CLOTHING
WELDING PPEs
•Protect front of body
from throat to knees
with suitable apron /
jacket.
•Use suitable leather
gloves to protect wrists
and hands.
•High cut safety leather
shoes.

14. • POWER SOURCE: Correctly connected and
adequately earthed.
• CABLES: Insulation proper, clear of ladders,
gangways and doors, do not allow traffic pass
over it, disconnect from power source before
joining/disconnecting cables.
• HOSES: Appropriate hoses, Connections
leak proof, clear of gangways, doors and
ladders, avoid being crushed by weights,
kinks free etc.
WELDING-SAFETY MEASURES
PRE WELDING SAFETY MEASURES

15. • LEADS:
•Properly insulated.
•Lead thimbles are properly connected.
• Avoid kinks.
•Return welding lead connected to only welded
piece unless special procedures exist, return
leads must be as short as possible and have
sufficient current carrying capacity.
•Do not wrap welding leads around components,
work table, scaffolding etc.
WELDING-SAFETY MEASURES
PRE WELDING SAFETY MEASURES

16. • HOLDERS:
•Completely insulated holder when
welding in confined space, difficulty to
access weld, steels that may be
hardened by accidental ‘arcing’.
•Avoid contact of partly insulated holder
with metal parts causing stray flashes.
•When holder not in use secure it in
insulated hook.
WELDING-SAFETY MEASURES
PRE WELDING SAFETY MEASURES

17. • GAS CYLINDERS: Healthy condition, keep
them away from welding arc, fitted with
pressure regulator and calibrated gauge.
• WORKING AREA: Proper hot job enclosure,
Neat and tidy, free from flammable materials,
fire extinguisher available, properly ventilated
etc.
• SCREENING: screen available to avoid
exposure of arc light to others.
WELDING-SAFETY MEASURES
PRE WELDING SAFETY MEASURES

18. • Ensure weld spatters and slag do not fall
beyond hot job enclosure.
• Welder assistant should be wearing eye
protective to avoid exposure of welding
arc.
WELDING-SAFETY MEASURES
DURING WELDING SAFETY MEASURES

19. • House keeping of working area.
• Barricading of welded components to
avoid human contact.
• Disconnect power supply.
• Wrap up welding leads and power cables.
WELDING-SAFETY MEASURES
POST WELDING SAFETY MEASURES

20. TYPES OF WELDING
Welding
Gas
Welding
Oxy-
Acetylene
Welding
Oxy-
Hydrogen
Welding
ElectricWelding
SMAW GTAW Submerged
Arc Welding
MIG
Welding
Induction
Welding
etc.
Forge
Welding

21. • BASE METALS: Metals which are
required to be welded.
• ELECTRODE/FILLER WIRE: Third Metal
require to form weld joint or Metal rod
require for arc production.
• WELD PUDDLE: Pool of molten metal.
• SLAG: Deposition of electrode coating on
weld.
TYPES OF WELDING
WELDING GLOSSARY

23. •Non-consumable electrode made up of
tungsten.
•Shielding gas (inert) to cover weld
puddle.
•Filler wire
TYPES OF WELDING
GAS TUNGSTEN ARC WELDING-GTAW
Requirements

24. • Electric arc is established by touching electrode
with workpiece.
• As soon as arc is developed, operator maintains
a constant gap of 1.5 to 3mm between electrode
and workpiece.
• Arc ionizes inert gas and allows welding current
to flow through it and causes base metal to melt.
• Then welder add filler wire in molten metal pool
to achieve desire weld quality.
TYPES OF WELDING
GAS TUNGSTEN ARC WELDING-GTAW
Operation

25. TYPES OF WELDING
GAS TUNGSTEN ARC WELDING-GTAW

26. TYPES OF WELDING

27. • Base metal positive.
• Electrode negative.
• Direct Current.
• Welding Speed is slow
• Can be employed on all types of weld
geometries
• Highest quality root over wide range of
thicknesses and weld geometries.
TYPES OF WELDING
PARTS OF GAS TUNGSTEN ARC
WELDING-GTAW
Salient Features

28. •Consumable electrode.
TYPES OF WELDING
SHIELDED METAL ARC WELDING-SMAW
Requirements
Operation
•Electric arc is established by touching an consumable
electrode with work piece.
•As soon as arc is established, operator maintains a gap
between electrode and work piece.
•Electric arc melts base metals.
•Electrode flux provides shielding gas when melts and
electrode core provides filler metal to have desire
properties of weld joint.

29. • Base metal negative
• Electrode positive
• Both DC and AC are source suitable
• Welding speed is greater than GTAW
• Can be employed on all types of weld
geometries.
• Weld spatters
• Slag required to be grind off
TYPES OF WELDING
SHIELDED METAL ARC WELDING-SMAW
Salient Features

30. TYPES OF WELDING
SHIELDED METAL ARC WELDING-SMAW

31. • This type of welding is done by machine and
employs bare rod.
• Bare electrode is already place in machine
which produces electric arc.
• A powder is showered by machine which
covers molten pool to avoid contamination.
• After welding, burned flux is recovered again
for reuse.
TYPES OF WELDING
SUBMERGED ARC WELDING-SMAW
Operation

32. • Very high thickness plates can be welded
in quick time.
• In case of high pre heat temperatures and
manual welding is not possible, this
technique is very conducive.
• This welding can be only be applied for flat
position.
TYPES OF WELDING
SUBMERGED ARC WELDING-SAW
Salient Features

33. TYPES OF WELDING
SUBMERGED ARC WELDING-SMAW

34. SUBMERGED ARC WELDING-SMAW

35. • Electrodes and filler wires classification
and their use is defined by American
Welding Society (AWS).
• Moreover, weld joint inspection is also
covered by AWS (B1.11).
• AWS publishes codes and guidelines for
welding of structures (AWS D1.1), welding
of carbon steels, alloy steels etc.
• AWS is being endorsed by ASME/ANSI.
TYPES OF WELDING
ELECTRODES & FILLER WIRES

36. TYPES OF WELDING
ELECTRODES & FILLER WIRES
ELECTRODES/FILLER WIRES FOR SMAW, GTAW & SAW
SMAW
E 7018 (Carbon Steel SFA 5.1)
E 6010 (Carbon Steel SFA 5.1)
E 9015 (Low Alloy Steels SFA 5.5)
GTAW
ER 70S-3 (Carbon Steel SFA 5.18)
ER 80S B2 (Low Alloy SFA 5.28)
ER 308 (Stainless Steel SFA 5.9)
SAW EL 8 (Mild Steel SFA 5.17)

37. • Take an example
E-7018
TYPES OF WELDING
ELECTRODES DECODING
Electrode Tensile
Strength
(Ksi) Welding
Position
Type of Flux
Coating
Alphabet Shows Either Electrode (E) or Filler Wire (ER)
First two numeric digit shows minimum tensile strength in Ksi

38. 1
All Positions (Flat, horizontal,
vertical and over head positions)
2 Flat and horizontal positions
3 Flat position only
TYPES OF WELDING
ELECTRODES DECODING
Third numeric digit shows ‘Welding Position’
Last numeric digit indicates type of flux and type of power supply required
for electrode
0 High Cellulose Sodium DC
1 High Cellulose Potassium AC or DC
8 etc. Iron Powder Low hydrogen AC or DC

39. • E 308-16
TYPES OF WELDING
ELECTRODES DECODING
Corrosion Resistant Electrodes
Alphabet Shows Either Electrode (E) or Filler Wire (ER)
308 shows 18% Cr and 8% Ni
1 shows suitable for all welding positions
6 shows suitable with both AC and DC

40. • Electrodes and filler wires are available in
number of sizes;
TYPES OF WELDING
ELECTRODES SIZES (Diameter of Core)
DESCRIPTION SIZES (mm)
ELECTRODES 1.6, 2.0, 2.5, 3.2, 4.0, 5.0, 6.0, 6.3, 8.0
FILLER WIRES 1.6, 2.4, 3.2, 6.0

41. WELDING ACCESSORIES
ELECTRODE HOLDERS
• Electrode holder is used to hold
and guide the electrode over the
seam to be welded.
• A good holder should be light to
reduce excessive fatigue while
welding, receive and eject
electrodes easily and be properly
insulated.
• Some holders are fully insulated
and some are semi insulated.
• Always connect holders firmly with
power cables.
• A loose connection where the
cable joins holder may overheat the
holder.
FULLY INSULATED
SEMI INSULATED

42. • Electrode holder is used to hold and guide
the electrode over the seam to be welded
• A good holder should be light to reduce excessive fatigue
while welding, receive and eject electrodes easily and be
properly insulated.
ELECTRODE HOLDERS
WELDING ACCESSORIES

43. SEMI INSULATED
Always connect holders firmly with power cables
A loose connection where the cable joins holder may overheat
the holder.
WELDING ACCESSORIES
ELECTRODE HOLDERS

44. WELDING ACCESSORIES
SMAW-ELECTRODE HOLDERS

45. WELDING ACCESSORIES
GTAW-ELECTRODE HOLDERS
CAP
TORCH BODY
ALUMINA
NOZZLES

46. WELDING ACCESSORIES
POWER SUPPLIES
WELDING TRANSFORMER
WELDING RECTIFIER
WELDING GENERATOR or CONVERTER
WELDING INVERTER
PORTABLE WELDING GENERATOR

47. WELDING ACCESSORIES
WELDING TRANSFORMER
• Provides AC current with
high amperes and less
voltage is received for
welding.
• Current regulator provided
for adjusting current.
• There are three types of
welding transformers i.e
single phase, two phase and
three phase.

48. WELDING ACCESSORIES
WELDING RECTIFIER
• Welding rectifier can provide
either AC or DC welding current.
• Rectifier operation is quieter.
•These machines offer greater
efficiency then their
counterparts.

49. WELDING ACCESSORIES
WELDING GENERATOR
• It is just an electric dynamo
which when driven by electric
motor or auto engine produces
electricity.
• These machines produces high
DC current 72Volts.
• These machines are usually
employed for heavy welding jobs.

50. WELDING ACCESSORIES
ELECTRODE OVEN
• Electrodes absorbs moisture in open
atmosphere.
• This causes porosity in weld metal and
cracking in HAZ.
• When electrodes absorbs moisture;
• A white layer is formed over it.
• Its flux starts disintegrating during
welding.
• Excessive spatter.
• Excessive rusting of core wire observes.
•Electrodes affected by moisture may be
used after draying in oven for approximately
an hour at 110 to 150°C.

51. • It is a document describing welding
procedures, which provides direction to
the welder or welding operators for making
sound and quality production welds as per
the code requirements.
WELDING PROCEDURE SPEC.
Definition

52. WELDING PROCEDURE SPEC.
Information Available in WPS
Type of Welding
Type of Weld Joint
Base Metals
Type of Filler Metal/Electrode
Welding Position
Preheat Requirement
Postweld Heat Treatment
Gas Characteristics
Electrical Characteristics
Welding Bead Technique
Current and Speed
Requirement
Miscellaneous Details

53. WELDING PROCEDURE SPEC.
Welding Joint Terminologies
Fillet Weld/Joint Lap Weld/Joint
Weld Root
Filling
Capping
Butt Weld/Joint

54. Root Pass Hot Pass
Fill Pass Cover/Capping
Pass
WELDING PROCEDURE SPEC.

55. WELDING PROCEDURE SPEC.
Fillet Welding Joint Terminologies

56. WELDING PROCEDURE SPEC.
Variations in Welding Joints

57. WELDING PROCEDURE SPEC.
Welding Joint Positions

58. WELDING PROCEDURE SPEC.
Welding Joint Positions

59. WELDING PROCEDURE SPEC.
Welding Beads
THERE ARE TWO TYPES OF WELD BEADS
A weld bead is the result of a welding pass that
deposits filler material.
Stringer Bead Weave Bead
DEPENDING ON HOW MUCH OSCILLATIONS WELDER USES

60. • When the welder uses
more oscillation while
applying filler material,
the result is weave
bead.
• Employed when large
amount of weld
deposit required.
WELDING PROCEDURE SPEC.
Weave Bead

61. Stringer Bead
WELDING PROCEDURE SPEC.
• When the welder uses
very little oscillation while
applying filler material, the
result is stringer bead.
• Stringer beads are
generally not very wide
and can be used in any
welding position.

62. WELDING PROCEDURE SPEC.
Current Selection
Electrode Size Welding Deposition Rate Type of Job
Welder’s Skill

63. WELDING DISCONTINUITIES
Discontinuity
Discontinuities are interruptions in the desirable physical
structure of weld.
Defect
When discontinuities reach to an extent that it poses
danger to the fitness for purpose of a weld then it is called
defect.

64. WELDING DISCONTINUITIES
Classification of Welding Discontinuities
DESIGN RELATED
WELDING PROCESS RELATED
METALLURGICAL

65. • It includes problems related to
1. Design detail.
2.Choice of wrong type of weld
joint for a given application.
3.Undesirable changes in cross
section
WELDING DISCONTINUITIES
Discontinuity-Design Related

66. WELDING DISCONTINUITIES
Discontinuity-Welding Process Related
Undercut
Slag Inclusion
Porosity
Overlap
Backing Piece Left On
Shrinkage Voids
Oxide Inclusions
Lack of Fusion
Lack of Penetration
Craters
Spatters
Underfill
Melt Through Arc Strikes

67. WELDING DISCONTINUITIES
Undercut
A groove melted into the base metal
adjacent to the toe or root of a weld
and left unfilled by weld metal.
Remedial Measures
•Decrease current, travel speed
and electrode diameter.
•Change electrode angle.
•Avoid weaving.

68. WELDING DISCONTINUITIES
Slag Inclusion
Non-metallic solid material
entrapped in weld metal or
between weld metal and
base metal.
Remedial Measures
•Decrease cooling rate.
•Increase temperature of weld puddle.
•Improve weld geometry.

69. WELDING DISCONTINUITIES
Porosity
Pores formed by gas
entrapment during welding.
Remedial Measures
•Remove rust, scale, paint, moisture etc.
•Eliminate moisture from flux or shielding gas.
•Provide sufficient shielding.
•Keep weld molten metal long enough to escape gases.

70. WELDING DISCONTINUITIES
Overlap
The protrusion of weld metal
beyond toe, face or root of
the weld.
Remedial Measures
•Change electrode angle.
•Use higher travel speed.
•Use high welding current.

71. WELDING DISCONTINUITIES
Backing Piece Left On
Failure to remove material placed
at the root of a weld joint to support
molten weld metal.
Remedial Measures
•Ensure proper removal of backing
material.

72. WELDING DISCONTINUITIES
Shrinkage Voids
Cavity type discontinuity
formed owing to shrinkage
during solidification.
Remedial Measures
•Slow cooling.

73. WELDING DISCONTINUITIES
Oxide Inclusions
Particles of surface oxides which
have not melted and are mixed into
the weld metal.
Remedial Measures
•Clean joint and weld area
thoroughly prior welding.

74. WELDING DISCONTINUITIES
Lack of Fusion
A condition in which fusion is
less than complete.
Remedial Measures
•Increase heat input.
•Improve joint geometry.
•Reduce travel speed
•Use proper electrode angle.

75. WELDING DISCONTINUITIES
Lack of Penetration
A condition in which joint
penetration is less than
required.
Remedial Measures
•Increase heat input.
•Improve joint geometry.
•Reduce travel speed
•Use proper electrode angle.

76. WELDING DISCONTINUITIES
Craters
Depression at the termination
of weld bead.
Remedial Measures
•Fill crater before breaking arc.
•Employ backstepping technique.

77. WELDING DISCONTINUITIES
Spatters
Metal particles which are expelled
during welding that do not form
part of weld.
Remedial Measures

78. WELDING DISCONTINUITIES
Underfill
Depression on the face of weld
or root surface extending below
the surface of the adjacent base
metal.
Remedial Measures
• To minimize underfill, voltage, travel
speed and root opening should be
reduced.

79. WELDING DISCONTINUITIES
Arc Strike (Arc Burn)
Discontinuities consisting of any localized
re-melted metal, heat effected metal or
change in surface profile of any part of weld
or base metal resulting from arc.
Remedial Measures
• Ensure proper handling of welding torch.

80. WELDING DISCONTINUITIES
HI-LO (Misalignment)
Misalignment of welding joint.
Remedial Measures
• Careful while joint tacking.
•Ensure same Inside diameter of welded pipes
etc.

81. WELDING DISCONTINUITIES
Cracking
Fracture type discontinuities.
Remedial Measures
•Proper preheating.
•Proper post heating.
•Use proper electrode that has
sufficient ductility. etc.
Discontinuity-Metallurgy Related

82. THANKYOU

83. Standard Number† Title
AWS A02.4 Standard symbols for welding, brazing, and non-destructive examination
AWS A03.0 Standard welding terms and definitions
AWS A05.1 Specification for carbon steel electrodes for shielded metal arc welding
AWS A05.18 Specification for carbon steel electrodes and rots for gas shielded arc welding
AWS B01.10 Guide for the nondestructive examination of welds
AWS B02.1 Specification for Welding Procedure and Performance Qualification
AWS D01.1 Structural welding (steel)
AWS D01.2 Structural welding (aluminum)
AWS D01.3 Structural welding (sheet steel)
AWS D01.4 Structural welding (reinforcing steel)
AWS D01.5 Bridge welding
AWS D01.6 Structural welding (stainless steel)
AWS D01.7 Structural welding (strengthening and repair)
AWS D01.8 Structural welding seismic supplement
AWS D01.9 Structural welding (titanium)
AWS D08.1 Automotive spot welding
AWS D08.6 Automotive spot welding electrodes supplement
AWS D08.7 Automotive spot welding recommendations supplement
AWS D08.8 Automotive arc welding(steel)
AWS D08.9 Automotive spot weld testing
AWS D08.14 Automotive arc welding(aluminum)
AWS D09.1 Sheet metal welding
AWS D10.10 Heating practices for pipe and tube
AWS D10.11 Root pass welding for pipe
AWS D10.12 Pipe welding (mild steel)
AWS D10.13 Tube brazing (copper)
AWS D10.18 Pipe welding (stainless steel)
AWS D11.2 Welding (cast iron)
AWS D14.1 Industrial mill crane welding
AWS D14.3 Earthmoving & agricultural equipment welding
AWS D14.4 Machinery joint welding
AWS D14.5 Press welding
AWS D14.6 Industrial mill roll surfacing
AWS D15.1 Railroad welding
AWS D15.2 Railroad weldingpractice supplement
AWS D16.1 Robotic arc welding safety
AWS D16.2 Robotic arc welding system installation
AWS D16.3 Robotic arc welding risk assessment
AWS D16.4 Robotic arc welderoperator qualification
AWS D17.1 Aerospace fusion welding
AWS D17.2 Aerospace resistance welding
AWS D18.1 Hygienic tube welding (stainless steel)
AWS D18.2 Stainless steel tube discoloration guide
AWS D18.3 Hygienic equipment welding