SP

WIS 5 CLASS NOTES

BI

1
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 JOINT DESIGN
This section introduces typical joint geometries involved in joining plates together and describes the
types of weld used in these joint configurations with typical features of butt and fillet welds.

Types of joints

(Right angle on the

same axis)

(5- 90o)
(0-30o)

( 135 – 180o ) (0-5o) (Open and closed

30 -135o)
SP
Types of weld
BI

2
NEZAR ELAHI M
+91 9633789674
BLASTLINE
nezaradnoc@gmail.com
 SP
Design throat thickness
Design throat (a)

Leg length (z)

BI

Actual throat = design throat + cap hight

length

Base metal or

3
 Butt weld joint configurations

• A closed square edge butt joint is used in thick plate

for keyhole welding processes such as laser or
electron beam welding (EBW).
• A square edged open butt joint is used for thinner
plate up to 3mm thickness for arc welding in a single
pass or in thick plate for welding processes such as
electroslag welding.

• Single sided preparations are normally made on

thinner materials, or when access from both sides
is restricted

• Double sided preparations are normally made on

thicker materials, or when access form both sides
SP is unrestricted
BI

❖ V preparations are usually used for plate of 3-20mm thickness.

❖ An alternative is a U preparation (or J preparation if only one side has the edge preparation),
This is also used in thicker plate over 20mm thickness
❖ J or U preparation require a bevel angle, root face, root gap and additional a root radius and
land

❖ Double side preparations have less weld volume and less stress than single side
preparations

4
NEZAR ELAHI M
+91 9633789674
BLASTLINE
nezaradnoc@gmail.com
 WELDING PROCESS
Welding
Permanent joining of materials by the application of heat only (fusion welding) or heat and pressure
(pressure welding)

Fusion process
Manual Welding

1. SMAW/ MMAW (111) constant current and drooping characteristics

2. TIG/ GTAW (141)

Semi-Automatic

3. GMAW – MIG (131) AND MAG (135) CONSTANT VOLTAGE AND FLAT
4. FCAW – (136) characteristics
Fully Automatic
5. SAW (121)
If SAW current > 1000 Ampere, constant
current & drooping characteristics

6. Electro slag

7. electron beam

8. laser beam
SP
pressure welding

1. friction

2. forge

3. resistance
BI

5
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com BLASTLINE
 Process polarity Inclusions
1. SMAW 1. Slag
2. TIG 2. Tungsten
DC + , DC- , AC
3. SAW 3. Copper, slag
4. GMAW DC+ 4. Silica , copper
5. FCAW DC+, DC- 5. Slag

SMAW
• Filler material – electrodes
• Shielding- flux

• Mainly for steel welding, used in material

thickness above 3mm

MMAW OR SMAW Electrodes (AWS)

1) E 6010
• Cellulose
• Cellulose compound
• Root welding
• High welding speed and deep penetration
• For stove piping (V-D welding)
• No baking, no drying
SP
• High H2 level
• All position

2) E 7018
• Basic
• Calcium compound
BI

• High quality
• Low H2 level
• Baking and drying
• High thickness jobs
• All position
3) E 6013
• Rutile
• Titanium oxide
• Medium H2 level
• Low quality
• General purpose / positional welding

6
 • Only drying
• All position
4) E 7024
• Rutile recovery
• Iron powder
• High recovery rate
• Medium H2 level
• Only drying
• PA and P B position only

Vaccum pack electrodes

Normal pack electrodes

SP
❖ Electrode size :350mm – 450mm length and 2.5mm – 6mm diameter

Electrode British Representation

35
BI

7
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 Sometimes ‘A/B’ classification before ‘E’
If A → 35 x 10 yield strength , In N/mm²
B → 35 x 10 Tensile strength , In N/mm²
If no A/B→ 35 x 10 yield strength , In N/mm²

American Standard

7 8

E7018 → 70 x 1000 PSI Tensile Strength

SP
LAST NUMBERS
• 0, 1 – CELLULOSE
• 2,3,4 – RUTILE
• 5,6,,8 – BASIC
BI

Electrode Size – 350 to 450 mm length and 2.5 to 6 mm diameter

TIG

• Filler material – filler wire

• Shielding - gas
• Filler wire size – 1 to 2.5 mm diameter, 1 meter length
• Almost all material welding, used in upto 10mm job thickness
GAS
• 100% Argon- all materials < 3mm thick • Argon -hydrogen -austenitic
• Argon-Helium mixture – all materials (3-10mm thick) stainless steel and Cu-Ni alloys
• Argon-Nitrogen duplex steel
8
NEZAR ELAHI M
+91 9633789674
BLASTLINE
nezaradnoc@gmail.com
 Tungsten electrode types
1. Pure tungsten - AC current
2. Thoriated - DC current
(small radio active)

3. Ceriated and lanthaniated – DC or AC

4. Zirconiated - AC

Shape of Tungsten electrode tip

• Flat and round -AC

SP
• Sharp or vertex angle – DC
BI

Filler wire

9
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 GMAW (MIG OR MAG)

• Filler material – filler coil • Used in thickness 3-30mm

• Shielding-gas
• Filler wire size- 0.6 to 1.6mm diameter and it weights in kg
• Mostly used for shop welding, ferrous and non ferrous materials

SP
BI

10
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 Metal transfer modes

• Depends on current, voltage, filler wire diameter material thickness

Dip Spray pulsed Globular

• Lengthy droplets • Small continuous • Small droplets • large droplets

• Short circuit method droplets • Pulsed current • only for carbon
• Low current • High current • All position steel
• Chance of lack of • Flat & H-V fillet • 100% CO2 only, so
fusion welds not used in british
• Inductance coil to sites
control current then • Flat position only
control spatter
• All position

SP
GAS

MIG

100 % Ar for light alloys Aluminium, copper , Nickel , Mg.....

Ar –He

MAG
BI

100 % CO2

Ar – co2 Carbon Steel

Ar – He –Co2

Ar – o2 Stainless Steel

He – Ar – Co2

Ar – He – N2 → Duplex Steel

11
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 FCAW

• Filler material – filler coil

• Shielding – gas , flux
• Mostly used for site welding
• Comparing to GMAW process FCAW have high current high deposition high production high
welding speed
• Used in thickness 3-30mm

Metal transfer mode

Pulse, spray, globular (not used in site)

Dip – not used in FCAW (low current)

GAS

Same like MAG process but percentage different

SAW Process
SP
• Filler material – filler coil
• Shielding – flux
• Thickness above 15mm
• Mostly in flat position, rarely horizontal vertical position
BI

12
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 SAW have

1. High heat input

2. High current
3. High voltage
4. High dilution
5. High penetration
6. High deposition
7. High thickness welding

Types of flux

Agglomerated Fused
• Powder form • Small particles
• High quality • Low quality
• Smooth • Sharp/brittle
• Single time use • Recyclable
• Matty/dull • Glossy, black
• High hygroscopic • Less hygroscopic
• Drying &baking • Only drying
• Good impact properties SP • Not good impact properties
BI

13
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Process and H2 level

• TIG → < 3 ml / 100 g weld Metal

• SMAW

- BASIC < 5ml / 100 g weld Metal

- Rutile 25 – 30 ml/ 100 g weld Metal

- Cellulose 80 – 90 ml / 100 g weld Metal

• GMAW → < 5ml / 100 g weld Metal

• SAW → < 10 ml / 100 g weld Metal
• FCAW → < 15 ml / 100 g weld Metal

Open circuit voltage(OCV)

• AC,DC positive
70 – 90 V
And basic electrode
• DC negative - 50 -60 V
• Cellulose or rutile electrode - 50 V

Welding voltage ( Arc voltage)

• AC – 10 -12 V
SP
• DC - 20 – 40 V, SAW upto 45V
• Dip and pulse - less than 24 V
• Spray and globular - greater than 24 V

+ -
BI

DC AC DC

• High penetration • Medium penetration & • Low penetration

• Low deposition deposition • High deposition
• Deeper weld • Wider weld

• Arc length Distance between filler tip to job

• Arc voltage Welding voltage or potential difference between two points
• CTWD Contact tube to work piece distance

14
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 • EE (electrode extension) distance b/w contact tube to filler tip
• ESL (electrode stick out length) holder nozzle tip to filler tip

Arc length High deposition

Increase

High penetration
Decrease

Arc voltage low penetration

Low deposition
CTWD wider weld
Deeper weld
EE
ESL
SP
• CTWD 1/∝ Current

Basic Electrode Treating Method

BI
Vaccum pack electrode Direct use (4 hour)
After 4 hour
Normal pack electrode Baking

Mother oven (350oC,1 hour/2 hour)

Rebaking

(Max: 2 times) Holding oven (150oC)

Portable oven/Quiver(70 -90oC) 4 hour

After 4 hour

15
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 MATERIAL TESTING
NDT

Cleaning and preparation for NDT

PT

MT pre preparation and post cleaning important

UT

RT - preparation not important but some critical joints, Fix film after remove paints

- Post cleaning not done

SP
PT,MT ( Surface defects)

RT,UT (Internal Defects)

BI

PENETRANT TEST

The technique is based on the ability of a liquid to be drawn into a "clean" surface discontinuity by
capillary action. After a period of time called the "dwell time", excess surface penetrant is removed
and a developer applied. This acts as a blotter that draws the penetrant from the discontinuity to
reveal its presence.

• All materials except porous material

• Temp : 5 - 50°c (old) New (10-50°c )
• Surface defects only
• All consumables should be of same manufacturer

STEPS

1. PRECLEANING
2. APPLY PENETRANT

PT Chemicals
16
 3. DWELL TIME (5 – 20 MINS) OR (5-15 MINS)
4. EXCESS PENETRANT REMOVAL
5. APPLY DEVELOPER
6. DEVELOPING TIME (10 – 30 MINS)OR (0-30 MINS)
7. INTERPRETATION
8. POST CLEANING.

SP
Types of penetrants or test - 1.Fluorescent 2.non fluorescent (colour contrast / visible)
BI

MAGNETIC TESTING

The first step in a magnetic particle testing is to magnetize the component that is to be inspected. If
any defects on or near the surface are present, the defects will create a leakage field. After the
component has been magnetized, iron particles, either in a dry or wet suspended form, are applied
to the surface of the magnetized part. The particles will be attracted and cluster at the flux leakage
fields, thus forming a visible indication that the inspector can detect.

• Only ferro magnetic materials

• Curie temp : 650°c (Temperature at which material loss its magnetic properties)
• Surface and near surface defects
• White contrast paint
• Iron powder ( Medium)
• All consumables should be of same manufacturer

17
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
Techniques

Yoke, prod, coil, flexible cables

Yoke calibration (lifting capacity)

AC Yoke – 4.5 kg

DC yoke
Minimum 18.1 kg
Permanent Yoke

Field indicators
SP
Pie gauge , Burmah – Castrol strip.
BI

Pie gauge

Burmah – Castrol strip.

Head shot

18
 yoke
prod

coil
Permanent yoke

ULTRASONIC TESTING
SP
The sound Energy is introduced and Propagates through the materials in the form of waves. When
there is a discontinuity (such as a crack) in the wave path, part of the energy will be reflected back
from the Flaw surface. The reflected wave signal is transformed into an electrical signal by the
Transducer and is displayed on a screen.
BI

19
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 • SURFACE AND SUB SURFACE DEFECTS
• MOSTLY IN FERRITIC MATERIALS
• GOOD FOR PLANAR DEFECTS ( LAMINATION, LAMELLAR TEARING, LACK OF FUSION ETC.)
• Temperature → UPTO 600 C

IN UT

• MACHINE
• PROBE
• COAXILE CABLE
• COUPLANT
• STANDARD BLOCKS (V1, V2, STEP WEDGE)
• REFERENCE BLOCKS (SDH, FBH, NOTCH)

PROBES

1. NORMAL / COMPRESSIONAL PROBE

2. TR PROBE OR DUAL PROBE LAMINATION CHECKING & THICKNESS GAUGING

3. ANGLE PROBE / SHEAR PROBE - WELDING DEFECTS

SP
RADIOGRAPHIC TESTING

In radiographic testing, the part to be inspected is placed between the radiation source and a piece
of radiation sensitive film. The radiation source can either be an X-ray machine or a radioactive
source The part will stop some of the radiation where thicker and more dense areas will stop more
of the radiation. The radiation that passes through the part will expose the film and forms a
shadowgraph of the part. The film darkness (density) will vary with the amount of radiation reaching
the film through the test object where darker areas indicate more exposure (higher radiation
BI

intensity) and lighter areas indicate less exposure (lower radiation intensity).

20
 • ALL MATERIALS
• SURFACE AND SUBSURFACE DEFECTS
• GOOD FOR VOLUMETRIC DEFECTS (POROSITY, SLAG, ETC.)
• IONISING RADIATION IS USED
• HIGH QUALITY
• HIGH HAZARDOUS
• MOSTLY IN AMBIENT TEMP.
• DOUBLE SIDE ACCESS NEEDED

Techniques
1. Single wall single image (SWSI)
• ALL PLATES
• PANORAMIC SHOT (PIPE ABOVE 600 MM OUTER DIAMETER)
• Double wall single image (DWSI) (PIPE ABOVE 100 MM OUTER DIAMETER)
• DOUBLE WALL DOUBLE IMAGE (DWDI) (PIPE UPTO 100 MM OUTER DIAMETER)

FILM DENSITY
Measured by Densitometer – Calibrated by densitostrip

IMAGE QUALITY (SENSITIVITY)

Penetrameter or lQI (Image quality indicator)

SP
HOLE TYPE
BI

WIRE TYPE

ISOTOPES THICKNESS RANGE HALF LIFE PERIOD

1. Iridium 192 10 – 75 mm 74 Days

2. Cobalt 60 40 mm above 5.3 Years
3. Cesium 137 20-80 mm 33.3 Years
4. Yetterbium 169 5-15 mm 31 Days
5.. Thulium 170 ≤ 5 mm 128 Days
6.. Selenium 75 10-40mm 120 Days

21
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 UNITS

X- RAY GAMMA- RAY

Voltage – Kv Source strength – Curies (ci)
Current - mA Energy Level - Mev
Penetration depends on KV Penetration depends on isotope

DESTRUCTIVE TESTING
Destructive or mechanical test are generally carried out to ensure that the required levels of certain
mechanical properties or levels of quality have been fully achieved.

The mechanical properties or material characteristics most commonly evaluated include:

Hardness The ability of a material to resist indentation

The opposite of hard is soft

Toughness
SP
The ability of a material to resist fracture under impact loads

The opposite of tough is brittle

Strength The ability of a material to resist a force. (normally tension)

The opposite of strong is weak

Ductility The ability of a material to plastically deform under tension

BI

The opposite of ductile is un-ductile

Static load Load at rest

Dynamic load Moving load
Impact load Sudden load
Cyclic load Continuous load

22
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Quantitative test Qualitative test
(used to measure quantity, have units) (used to assess quality, have no units)

• Hardness testing (Vickers/Brinell/Rockwell) • Macro testing

• Toughness testing (Charpy V/Izod/CTOD) • Bend testing (Side/Face/Root)
• Tensile testing (Transverse/All weld metal) • Fillet weld fracture testing
• Butt weld (Nick-break) testing

Hardness testing

Measurement of resistance of a material against penetration of an indenter under a constant

load.

Brinell Hardness Test

• Hardened steel ball (or ceramic ball)of given diameter is subjected for a given time to a
given load.
• Load divided by area of indentation gives Brinell hardness in kg/mm2.
• More suitable for on site hardness testing.

SP
Rockwell Hardness Test
BI

• Rockwell test measuring the depth of penetration of an indenter under a large load
compared to the penetration made by a pre load
• The result is a dimensionless number noted as HRA,HRB,HRC etc.

23
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 Vickers Hardness Test

• Indentation body is a square based diamond pyramid (136° included angle).

• The average diagonal (d) of the impression is converted to a hardness number from a table.
• It is measured in HV5, HV10 or HV025.

Charpy impact testing

SP
BI

24
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 • The Charpy impact test, also known as the Charpy V-notch test, is a high strain-rate test that
involves striking a standard notched specimen with a controlled weight pendulum swung
from a set height. The impact test helps measure the amount of energy absorbed by the
specimen during fracture.
• Unit measures in Joules
• More energy absorbed Ductile
• Less energy absorbed Brittle
• Steel that may have very good toughness at ambient temperature may show extreme
brittleness at sub zero temperature
• Transition point ductile to brittle changing point

CTOD testing (Crack Tip Open Displacement)

• Measure fracture toughness

• Crack size or crack growth

SP
BI

• A load is applied to the specimen to cause bending and induce a concentrated stress at the
tip of the crack and a clip gauge, attached to the specimen across the mouth of the
machined notch, gives a reading of the increase in width of the mouth of the crack as the
load is gradually increased
• Fracture toughness is expressed as the distance that the crack tip opens
• The clip gauge enables a graph to be generated and converted to CTOD value in millimeters

25
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Tensile testing

(Universal testing machine)

• Specimens are fitted into the jaws of a tensile testing machine and subjected to a continually
increasing tensile force until the specimen fractures.

Transverse tensile testing

• Find strength of joint (UTS) (Rm)

Joint

Load Load

Weld
Base metal

All-weld tensile test (longitudinal tensile test)

(50mm)

Load Load
SP
BI

• Measure weld metal strength (Rm)

• Ductility
elongation ductility (A%) , reduction ductility ( Z%)
• Proof stress (Rp)
• yield stress (Re)

• when we applied a load ,the specimen goes through two stages first one is elastic
stage(regain original position when release load) and second one is plastic stage (permanent
deformation)

26
Stress-strain curve

(Reduction)

(UTS)

Re

Plastic stage

Elastic stage

a. Hard material b. Tougher materials

UTS
SP
Rp Fracture • It is hard material so there is no
necking or reduction
BI

c. Some hard material

Bend test
• usually guided bend tests are used, guided means that the strain imposed on the specimen
is uniformly controlled by being around a former with a certain diameter
• Angle of bend (90o,120o,180o)
• Diameter of former (typical 4T)
• to determine the soundness of the weld zone
• bend test can also be used to find lack of fusion and give an assessment of weld zone
ductility
Face bend Face tension, root in compression
• Upto 12 mm thickness
Root bend root tension, face in compression
27

BLASTLINE
 • Above 12 mm side bend former fixed side in compression, other side in
tension

Fracture test
Fillet weld fracture

• To find lack of penetration/fusion, solid inclusions and porosity

• Specimens are made to fracture through their throat by hammering or pressing (2mm depth
longitudinal notch)
SP
BI

Nick-break fracture test (Butt weld)

• Used to assess root penetration/root fusion in double sided butt weld and the internal
soundness of single sided butt weld
• 2mm depth notch at both face and root, it may then be held in a bench vice and fractured
with a hammer blow
• It is also used to find inclusions and porosity

28
NEZAR ELAHI M
+91 9633789674
BLASTLINE
nezaradnoc@gmail.com
 •
SP
Macro test (used to assess the internal quality of the weld)
Purpose

To examine the weld cross section to give assurance that

• The weld has been made in accordance with the WPS

• The weld is free from defects
BI
increase

decrease

Toughness Strength
∝ this
If ∝
Ductility Hardness

WPS (Test for Procedure) WQT (WELDER QUALIFICATION TEST)

Tensile Bend
Hardness Fracture
Impact Toughness NDT
BEND Macro
Macro VISUAL
NDT
VISUAL

29
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 HEAT TREATMENT
WELDING RELATED

Preheat → (Minimum temp.) 50 - 250°c

Before welding before subsequent passes

Benefits Temperature Depends

a) Slow down cooling rate , reduce hardness 1. Hydrogen level
b) Diffuse H2 , prevent Hydrogen crack. 2. Thickness
3. Cev
c) Improve overall Fusion & Weldability
4. Arc Energy/Heat input
d) Reduce stress

e) Remove moisture

Interpass Temp. (Maximum Temp.) 50 - 250°c

• Between runs prior to next run

• Control mechanical properties

• Diffuse Hydrogen
SP
Post Heating

Maintaining welding temp. For another two hours

Diffuse h2 and prevent h2 cracking

Reduce hardness
BI

POST WELD HEAT TREATMENT (PWHT)

(Stress relieving)

• Relieves residual stress, reduce hardness, diffuse hydrogen, realign slip planes and

prevent distortion

Materials

C, C-Mn Steels Alloy Steels (Cr – Mo)

Soak temp. → 550 - 650°c Soak temp. → 700 - 760°c

30
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Thermal Cycle

• Controlled heating rate from 300°C to soak temperature.

• Minimum soak time at temperature.
• Controlled cooling to ~ 300°C.
• Soak time – 1 hour/ 25 mm thickness
• Heating rate – 60 to 200oC / hour
SP
MANUFACTURING RELATED

Upper critical temperature (UCT) – 900oC

Lower critical temperature (LCT) – 723oC
BI

1. ANNEALING (C-Mn and some low alloy steels)

31
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 • Temperature: 880-920o C
• Optimize ductility and softness
• Grain size – Large / Coarse

2. NORMALISING (C-Mn and some low alloy steels)

• Temperature: 880-920o C

• Optimise toughness and strength

• Grain size – Small / Fine

SP
3. HARDENING / QUENCHING (Some low alloy steels)

• Temperature : 880-920 oC
• Optimize strength and hardness
• Grain size – Small / Fine
BI

• Low toughness , zero ductility

• Martensite structure ( sudden cooling from UCT temperature)

4.TEMPERING (After quenching)

• Rebalance the properties of thermally quenched steels

• Temperature : 500-700 oC
• Increase toughness, some ductility
• Grain size – Small / Fine

32
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 5. SOLUTION TREATMENT (Only in Austenitic stainless steel such as 304 and 316 grades)

• Temperature : above 1000o C

• Prevent weld decay
SP
BI

• High heat input – low toughness

• Low heat input – high hardness (martensite

33
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 WELDABILITY OF STEELS
1.SOLIDIFICATION CRACKING

(Hot cracking, centerline cracking, longitudinal cracking, liquation cracking. Crater cracking)

• During or immediately after welding

• Last part weld metal solidification time

RATIO

W/D 1:2

• Forms mainly in weld

• All steels susceptible
SP
• Iron sulphide formation < 980oC
• Mostly in SAW welding process

Reason

• Increases sulphur, phosphor and carbon impurities

BI

• Wrong width – depth ratio ( increase crack in deep and narrow weld )
• High dilution
• High restraints ( increase stress)

Control

• Add manganese
• Correct width – depth ratio (i.e, no crack in shallow wider weld)
• Control impurities, dilution and stress

34
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 2.HYDROGEN CRACKING

(HICC, cold, delayed, toe, HAZ, under bead, chevron(45o) cracking )

• Forms in weld, parent metal, HAZ

• Mostly in all hard steels
• High alloy steels
• High CEV steels
• Forms after a specific time
( between 48 – 72 hours)

Reasons

• Hydrogen More than 15ml/100g of weld metal.

• Stress More than 0.5 of the yield stress.
• Temperature Below 300°C ( sudden cooling)
• Susceptible Microstructure Hardness Greater than 400HV Vickers (Martensite).
SP
( 300 – 350 HV )
Control

• Control hydrogen , stress, temperature, hardness

• Proper pre heat, interpass temperature, post heating, PWHT
• Maintain heat input
BI
3.LAMELLAR TEARING (step shape cracking)

• Location: Parent metal just outside the HAZ.

• Steel Type: Any steel type possible.
• Susceptible Microstructure: Poor through thickness ductility. ( < 20 % )
• Mainly in compound weld

35
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 • Forms during or immediately after
welding

Reasons

• High stress in Z direction ( through thickness direction)

• Poor through thickness ductility ( < 20 %)

Control

• Control stress
• Use Z quality steel ( > 20 % through thickness ductility )
• Use buttering layer SP
BI

STRA ( short transverse reduction area test )

• For finding Z direction ductility

36
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 4.WELD DECAY

(inter granular corrosion , inter crystalline corrosion , knifeline attack, sensitisation )

• Only austenitic stainless steel

• Temperature 600 – 850o C (550 -800 oC )
• HAZ area ( grain boundary region )
SP
• Weld decay may occur in austenitic stainless steels at the critical range of 600-850°C
chromium carbide precipitation at the grain boundaries takes place.
• At this temperature range chromium is absorbed by the carbon at the grain boundaries,
which causes a local depletion of chromium content in the adjacent areas.
• The depletion of chromium content in the affected areas results in lowering the materials
resistance to corrosion attack, allowing rusting to occur.
BI

Reasons

• High carbon content in austenitic stainless steel

• Formation of chromium – carbide at boundary

Control

• Use low carbon content austenitic stainless steel

• Use stabilized stainless steel ( stabilizer – titanium and niobium )
• Solution treatment over 1000o C

37
NEZAR ELAHI M
+91 9633789674
BLASTLINE
nezaradnoc@gmail.com
 Austenitic stainless steel

• 300 series
• FCC structure
• Low thermal conductivity
• High coefficient of thermal expansion
• Good toughness at low temperature
• High distortion
• Non magnetic
• No pre heat
• High chance of contamination and impurities during welding

Distortions
Factors affecting distortion

1.Parent material properties

2.Restraints
3.Joint design
4.Fit up
5.Welding sequence
SP
Reason for distortion

• Welding without restraints

• Uncontrolled heating & cooling
• low thickness
• Large bevel angle
BI

• Large weld metal volume

• Multi run
• High stress
• High heat inputs
• Manual welding process
Distortion control

• Increasing restraints
• Controlled heating & cooling
• high thickness, reduce weld volume, reduce heat input & stress
• Reducing bevel angles
• Single run
• Balanced welding technique
• Presetting of parts Back step welding

Back skip welding 38

 • Sequence welding

• Automatic welding process

• Neutral axis welding

Back step

Back skip

Alloying Elements and Properties

1) Carbon – Strength, Hardness

2) Manganese, nickel (Mn, N) – Toughness

SP
3) Chromium – Corrosion Resistance

4) Molybdenum – Creep Resistance

5) Silicon (Si) – De Oxidiser

6) Aluminium (Al) – De Oxidiser, Grain Refiner

7) Copper (Cu) – Atmospheric corrosion resistance

BI

• Sulphur cause – hot shortness ( crack)

• Phosphorous cause – cold shortness (crack)

• Titanium & niobium – stabilizers

39
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 CODES & STANDARDS
CODES & STANDARDS
1

• BSEN 288
• ISO 15614
• ASME sec IX Welding Qualification (WPS)
• AWS D1.1
• AWS D1.2

2.

• BSEN 287
• ASME Sec. IX
• AWS D1.1 Welder Qualification (WQT)
• AWS D1.2
• ISO 9606 – 1
• ISO 9606 – 2

3.
SP
• BSEN 970
• ISO 17637 Visual Inspection

4.
BI

• BSEN 1011 - Preheat or Heat input

5.

• BSEN 499
• ISO 2560 MMAW Consumables

6.

• ISO 2553
• BSEN 22553
• AWS A 2.4 SYMBOLS

40
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Welding Position

British positions AWS Position

PA – FLAT 1G/1F - FLAT

PB – HORIZONTAL – VERTICAL 2G/2F - HORIZONTAL

PC – HORIZONTAL 3G/3F - VERTICAL

PD – HORIZONTAL - OVER HEAD 4G/4F - OVERHEAD

PE – OVER HEAD 5G – FLAT, VERTICAL, OVERHEAD

HL045 – all positions, upwards 6G – All position

JL045 - all positions, downwards 6GR – All position with restrictional ring

PF– vertical up ( OFFshore, T,K,Y joints)

PG – vertical down

PH
PJ 5G

SP
BI

41
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 SP
BI

42
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 SP
BI

43
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 SP
BI

44
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 • High heat input →PF
• Low heat input and high current →PG
• Most fumes → PA (flat, IG)
• Weaving → PF

• Weaving ∝ heat input

• Travel speed ( run out length) 1/∝ heat input

• CTWD 1/∝ current

• Weaving 1/∝ travel speed

• Arc length ∝ arc voltage

SP
Symbol representation

4
BI

4 = Tail end
5 = Closed tail end

45
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com
 AWS A 2.4

Condition

• Symbol below reference line, weld goes to arrow side

• Symbol above reference line, weld goes to other side

BSEN 22553/ISO 2553

Condition

• Symbol near to reference line, weld goes to arrow side

• Symbol near to identification line, weld goes to other side

Symmetric and asymmetric weld

• Same dimensions on arrow side and other side ( symmetric )

• different dimensions on arrow side and other side ( Asymmetric )

Linear dimension and Cross sectional dimension

• Linear dimension on right side of the symbol

• Cross sectional dimension on left side of the symbol
SP
BI

46
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Duties of Welding Inspector

Before During After

• WPS, PQR • Parameters • Post heating

• fitup & PMI • Root inspection • Visual + Reporting
• Machine calibration & polarity • root pass • NDT
• Consumables • cleaning & NDT • Repair
• Safety • interpass temperature • PWHT
• Climate • hot pass, fill & cap • final dimensional checking
• Preheat • consumable • PMI
• Oven temperature • oven temperature • Hardness
• Climate • hydro, pneumatic
• Painting, insulation, jacketing etc.

Fracture appearance

SP
Ductile fatigue
Brittle
• • Cyclic/continuous load
• Sudden/impact load Sudden load
• • Smooth& Beach mark
• Flat and rough or crystalline rough and torn appearance
appearance
appearance
BI

Fatigue

47
NEZAR ELAHI M
+91 9633789674
nezaradnoc@gmail.com
 Welding procedure (WPS)
• Achieving quality job through controlling mechanical properties

PWPS

WPQR

WPS

• All prepared by welding engineer

SP
BI

48
Welding variables

1. Essential Any change, it affect mechanical properties, then

requalification of WPS
2. Supplementary
3. Non essential
Any change, not affect properties, then revision of WPS
Eg:

Essential supplementary Non Essential

• Process • Heat input • Cleaning

• Thickness • Welding position • Joint design
• Material
• Preheat
• Consumables
• PWHT
• Polarity etc. Welder qualification
• For checking welder skill and produce defect free weld

SP
BI

49
 Cutting gouging
Cutting
1. Oxyfuel
• For carbon steels & some alloys
• Preheat with fuel gas (acetylene, methyl, propane, propylene)
• Cutting gas – oxygen + fuel gas

Flames

Neutral, Carburizing & Oxidizing

2.Plasma

• Mostly all materials

• Cutting gas – plasma gas
• Tungsten electrode used for arc initiating, it produced pilot arc

Gouging
1.Air arc gouging

• Copper coated graphite electrode

• Cleaning with compressed air

2.Manual metal arc gouging

• Thick flux coated electrode

SP
• Cleaning with high stream shielding gas

Calculations

Fillet Weld
BI

1. Leg length (z) = Design throat (a) x 1.414 mm

2. Design throat = Leg length x 0.707 mm

Best Wishes....

50
NEZAR ELAHI M
+91 9633789674 BLASTLINE
nezaradnoc@gmail.com