ISF – Welding Institute RWTH – Aachen University Lecture Notes Welding Technology 1 Welding pps

ISF – Welding Institute
RWTH – Aachen University










Lecture Notes

Welding Technology 1
Welding and Cutting Technologies

Prof. Dr.–Ing. U. Dilthey
Table of Contents



Chapter Subject Page

0. Introduction 1
1. Gas Welding 3
2. Manual Metal Arc Welding 13
3. Submerged Arc Welding 26
4. TIG Welding and
Plasma Arc Welding 43
5. Gas– Shielded Metal Arc Welding 56
6. Narrow Gap Welding,
Electrogas - and
Electroslag Welding 73
7. Pressure Welding 85
8. Resistance Spot Welding,
Resistance Projection Welding
and Resistance Seam Welding 101

9. Electron Beam Welding 115
10. Laser Beam Welding 129
11. Surfacing and Shape Welding 146
12. Thermal Cutting 160
13. Special Processes 175
14. Mechanisation and Welding Fixtures 187
15. Welding Robots 200
16. Sensors 208
Literature 218
2003

0.
Introduction
0. Introduction 1
Welding fabrication processes are classified in accordance with the German Stan-
dards DIN 8580 and DIN 8595 in main group 4 “Joining”, group 4.6 “Joining by
Welding”, Figure 0.1.

Welding: permanent, positive joining
method. The course of the strain
lines is almost ideal. Welded joints
show therefore higher strength prop-
erties than the joint types depicted
in Figure 0.2. This is of advantage,
especially in the case of dynamic
stress, as the notch effects are
lower.








4.6.2
Fusion welding
1
Casting
5
Coating
Changing of
materials
properties
6
2
Forming

3
Cutting
4
Joining
4.4
Joining by
casting
4.1
Joining by
composition
4.7
Joining by
soldering
4.6
Joining by
welding
4.3
Joining by
pressing
4.2
Joining
by filling
4.8
Joining by
adhesive
bonding
4.6.1
Pressure welding
4.5
Joining by

forming
Production Processes acc. to DIN 8580
br-er0-01.cdr
Figure 0.1
© ISF 2002
Connection Types
Screwing
Riveting
Adhesive
bonding
Soldering
Welding
br-er0-02.cdr
Figure 0.2
0. Introduction 2

Figures 0.3 and 0.4 show the further subdivision of the different welding methods
according to DIN 1910.




Production processes
4
Joining
4.6
Joining by welding
4.6.2
Fusion welding
4.6.1

Pressure welding
4.6.1.1
Welding
by
solid bodies
Heated tool
welding
4.6.1.2
Welding
by liquids
Flow welding
4.6.1.3
Welding
by gas
Gas pressure-/
roll-/ forge-/
diffusion
welding
4.6.1.4
Welding by
electrical
gas discharge
Arc pressure
welding
4.6.1.6
Welding
by motion
Cold pressure-/
shock-/ friction-/
ultrasonic

welding
4.6.1.7
Welding by
electric current
Resistance
pressure
welding
Joining by Welding acc. to DIN 1910
Pressure Welding
© ISF 2002
br-er0-03.cdr
Figure 0.3
Production processes
4
Joining
4.6
Joining by welding
4.6.2
Fusion welding
4.6.1
Pressure welding
4.6.2.2
Welding
by liquids
4.6.2.3
Welding
by gas
4.6.2.5
Welding
by beam

4.6.2.4
Welding by
electrical
gas discharge
4.6.2.7
Welding by
electric current
Cast welding
Gas welding Arc welding Beam welding
Resistance
welding
Joining by Welding acc. to DIN 1910
Fusion Welding
br-er0-04.cdr
Figure 0.4
2003

1.
Gas Welding
1. Gas Welding 3

Although the oxy-acetylene process
has been introduced long time ago it
is still applied for its flexibility and mo-
bility. Equipment for oxyacetylene
welding consists of just a few ele-
ments, the energy necessary for weld-
ing can be transported in cylinders,
Figure 1.1.

Process energy is obtained from the
exothermal chemical reaction between
oxygen and a combustible gas, Figure
1.2. Suitable combustible gases are
C
2
H
2
, lighting gas, H
2
, C
3
H
8
and natu-
ral gas; here C
3
H
8
has the highest

calorific value. The highest flame in-
tensity from point of view of calorific
value and flame propagation speed is,
however, obtained with C
2
H
2
.





acetylene hose
oxygen cylinder with pressure reducer
welding rod
oxygen hose
welding nozzle
welding torch
acetylene cylinder with pressure reducer
welding flame
workpiece
1
9
7
2
6
4
5
3

8
1
9
7
2
6
4
5
3
8
br-er1-01.cdr
Figure 1.1
© ISF 2002
2770
2850
3200
0
200
400
600
645
0
ignition temperature [C]
O
oxygen
air
0.5
1.0
1.5
2.0

2.5
0
density in normal state [kg/m]
3
propane
2.0
0.9
oxygen
1.43
1.17
air
1.29
300
335
510
490
645
flame temperature with O
2
flame efficiency with O
2
flame velocity with O
2
KW
/
cm
2
cm
/
s

43
10.3
8.5
1350
370
330
br-er1-02.cdr
natural gas
propane
°C
k
Figure 1.2
1. Gas Welding 4

C
2
H
2
is produced in acetylene gas
generators by the exothermal trans-
formation of calcium carbide with wa-
ter, Figure 1.3. Carbide is obtained
from the reaction of lime and carbon
in the arc furnace.

C
2
H
2
tends to decompose already at

a pressure of 0.2 MPa. Nonetheless,
commercial quantities can be stored
when C
2
H
2
is dissolved in acetone
(1 l of acetone dissolves approx. 24 l
of C
2
H
2
at 0.1 MPa), Figure 1.4.





Acetone disintegrates at a pressure of
more than 1.8 MPa, i.e., with a filling
pressure of 1.5 MPa the storage of 6m³
of C
2
H
2
is possible in a standard cylin-
der (40 l). For gas exchange (storage
and drawing of quantities up to 700 l/h)
a larger surface is necessary, therefore
the gas cylinders are filled with a po-

rous mass (diatomite). Gas consump-
tion during welding can be observed
from the weight reduction of the gas
cylinder.




© ISF 2002
Acetylene Generator
loading funnel
material lock
gas exit
feed wheel
grille
sludge
to
sludge pit
br-er1-03.cdr
© ISF 2002
Storage of Acetylene
acetone
acetylene
porous mass
acetylene cylinder
filling quantity :
acetone quantity :
acetylene quantity :
~13 l
6000 l

15 bar
up to 700 l/h
cylinder pressure :
br-er1-04.cdr
N
Figure 1.3
Figure 1.4
1. Gas Welding 5

Oxygen is pro-
duced by frac-
tional distillation
of liquid air and
stored in cylinders
with a filling pres-
sure of up to 20
MPa, Figure 1.5.
For higher oxygen
consumption, stor-
age in a liquid state
and cold gasifica-
tion is more profit-
able.


The standard cylinder (40 l) contains,
at a filling pressure of 15 MPa, 6m³ of
O
2
(pressureless state), Figure 1.6.

Moreover, cylinders with contents of
10 or 20 l (15 MPa) as well as 50 l at
20 MPa are common. Gas consump-
tion can be calculated from the pres-
sure difference by means of the gen-
eral gas equation.









© ISF 2002
Principle of Oxygen Extraction
air
cooling
nitrogen
gaseous
cylinder
bundle
oxygen
oxygen
liquid
air
nitrogen
vaporized
liquid

tank car
pipeline
cleaning compressor separation
br-er1-05.cdr
supply
Figure 1.5
br-er1-06.cdr
Storage of Oxygen
50 l oxygen cylinder
protective cap
cylinder valve
take-off connection
gaseous
p = cylinder pressure : 200 bar
V = volume of cylinder : 50 l
Q = volume of oxygen : 10 000 l
content control
Q = p V
foot ring
user
gaseous
still
liquid
vaporizer
manometer
safety valve
filling
connection
liquid
N

Figure 1.6
1. Gas Welding 6

In order to prevent mistakes, the gas cylinders are colour-coded. Figure 1.7 shows a
survey of the present colour code and the future colour code which is in accordance
with DIN EN 1089.
The cylinder valves are also of different designs. Oxygen cylinder connections
show a right-hand
thread union nut.
Acetylene cylinder
valves are equipped
with screw clamp
retentions. Cylinder
valves for other
combustible gases
have a left-hand
thread-connection
with a circumferen-
tial groove.


Pressure regulators reduce the cylinder pressure to the requested working pres-
sure, Figures 1.8 and 1.9.

© ISF 2002
Gas Cylinder-Identification
according to DIN EN 1089
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actual condition DIN EN 1089
oxygen techn.
white
blue (grey)
blue
acetylene
brownyellow
nitrogen
darkgreen
darkgreen
black
argon
dark green
grey
grey
actual condition
DIN EN 1089
grey
grey

brown
helium
carbon-dioxide
grey
grey
grey
grey
argon-carbon-dioxide mixture
vivid green
hydrogen
red
© ISF 2002
Single Pressure Reducing Valve
during Gas Discharge Operation
br-er1-08.cdr
cylinder pressure working pressure
Figure 1.7
Figure 1.8
1. Gas Welding 7

At a low cylinder pressure (e.g. acetylene cylinder) and low pressure fluctuations,
single-stage regulators
are applied; at higher cylinder pressures normally two-stage pressure regulators are
used.
The requested
pressure is set by
the adjusting
screw. If the pres-
sure increases on
the low pressure

side, the throttle
valve closes the
increased pressure
onto the mem-
brane.


The injector-type
torch consists of a
body with valves
and welding cham-
ber with welding
nozzle, Figure 1.10.
By the selection of
suitable welding
chambers, the
flame intensity can
be adjusted for
welding different
plate thicknesses.




© ISF 2002
Single Pressure Reducing Valve,
Shut Down
br-er1-09.cdr
discharge pressure locking pressure
© ISF 2002

Welding Torch
br-er1-10.cdr
welding torch
injector or blowpipe
coupling nut
hose connection
for oxygen
A6x1/4" right
mixer tube mixer nozzle oxygen valve
injector
pressure nozzle
suction nozzle
fuel gas valve
welding nozzle
hose connection
for fuel gas
A9 x R3/8” left
welding torch head torch body
Figure 1.9
Figure 1.10
1. Gas Welding 8

The special form of the mixing chamber guarantees highest possible safety against
flashback, Figure 1.11. The high outlet speed of the escaping O
2
generates a nega-
tive pressure in the acetylene gas line, in consequence C
2
H
2

is sucked and drawn-in.
C
2
H
2
is therefore available with a very low pressure of 0.02 up to 0.05 MPa -
compared with O
2
(0.2 up to 0.3 MPa).














A neutral flame adjustment allows the differentiation of three zones of a chemical
reaction, Figure 1.12:

0. dark core: escaping gas mixture
1. brightly shining centre cone: acetylene decomposition
C
2

H
2
-> 2C+H
2

2. welding zone: 1
st
stage of combustion
2C + H
2
+ O
2
(cylinder) -> 2CO + H
2

3. outer flame: 2
nd
stage of combustion
4CO + 2H
2
+ 3O
2
(air) ->
4CO
2
+ 2H
2
O
complete reaction: 2C
2

H
2
+ 5O
2
->
4CO
2
+ 2H
2
O


© ISF 2002
Injector-Area of Torch
br-er1-11.cdr
acetylene
oxygen
acetylene
welding torch head
injector nozzle
pressure nozzle
coupling nut torch body
Figure 1.11
1. Gas Welding 9

By changing the mixture ratio of the
volumes O
2
:C
2
H
2
the weld pool can
greatly be influenced, Figure 1.13. At a
neutral flame adjustment the mixture
ratio is O
2
:C
2
H
2
= 1:1. By reason of the
higher flame temperature, an excess

oxygen flame might allow faster weld-
ing of steel, however, there is the risk
of oxidizing (flame cutting).
Area of application: brass
The excess acetylene causes the
carburising of steel materials.
Area of application: cast iron


© ISF 2002
br-er1-12.cdr
welding flame
combustion
welding nozzle
welding zone
centre cone
outer flame
3200°C
2500°C
1800°C
1100°C
400°C
2 - 5
Figure 1.12
© ISF 2002
excess of
acetylene
normal
(neutral)
excess of

oxygen
welding flame
ratio of mixture
effects in welding of steel
sparking
foaming
spattering
reducing oxidizing
consequences:

carburizing
hardening
Effects of the Welding Flame
Depending on the Ratio of Mixture
br-er1-13.cdr
Figure 1.13
1. Gas Welding 10

By changing the gas mixture outlet
speed the flame can be adjusted to
the heat requirements of the welding
job, for example when welding plates
(thickness: 2 to 4 mm) with the weld-
ing chamber size 3: “2 to 4 mm”, Fig-
ure 1.14. The gas mixture outlet
speed is 100 to 130 m/s when using a
medium or normal flame, applied to
at, for example, a 3 mm plate. Using a
soft flame, the gas outlet speed is
lower (80 to 100 m/s) for the 2 mm

plate, with a hard flame it is higher
(130 to 160 m/s) for the 4 mm plate.


Depending on the plate thickness are
the working methods “leftward weld-
ing” and “rightward welding” applied,
Figure 1.15. A decisive factor for the
designation of the working method is
the sequence of flame and welding rod
as well as the manipulation of flame
and welding rod. The welding direction
itself is of no importance. In leftward
welding the flame is pointed at the
open gap and “wets” the molten pool;
the heat input to the molten pool can
be well controlled by a slight move-
ment of the torch (s = 3 mm).


© ISF 2002
discharging velocity and weld heat-input rate: low
nozzle size: for plate thickness of 2-4 mm
balanced (neutral) flame
welding flame
2
soft flame
moderate flame
hard flame
discharging velocity and weld heat-input rate: middle

discharging velocity and weld head-input rate: high
3
4
br-er1-14.cdr
Effects of the Welding Flame
Depending on the Discharge Velocity
© ISF 2002
welding-rod flame
welding bead
weld-rod flame
Rightward welding
ist applied to a plate thickness of 3mm
upwards. The wire circles, the torch remains calm.
Advantages:

- the molten pool and the weld keyhole are easy to observe
- good root fusion
- the bath and the melting weld-rod are permanently protected
from the air
- narrow welding seam
- low gas consumption
Leftward welding
is applied to a plate thickness of up to 3 mm.
The weld-rod dips into the molten pool from time to time,
but remains calm otherwise. The torch swings a little.
Advantages:
easy to handle on thin plates
Flame Welding
br-er1-15e.cdr
Figure 1.14

Figure 1.15
1. Gas Welding 11

In rightward welding the flame is di-
rected onto the molten pool; a weld
keyhole is formed (s = 3 mm).
Flanged welds and plain butt welds
can be applied to a plate thickness of
approx. 1.5 mm without filler material,
but this does not apply to any other
plate thickness and weld shape, Fig-
ure 1.16.

By the specific heat input of the differ-
ent welding methods all welding posi-
tions can be carried out using the
oxyacetylene welding method, Figures
1.17 and 1.18



When working in tanks and confined
spaces, the welder (and all other per-
sons present!) have to be protected
against the welding heat, the gases
produced during welding and lack of
oxygen ((1.5 % (vol.) O
2
per 2 % (vol.)
C

2
H
2
are taken out from the ambient
atmosphere)), Figure 1.19. The addi-
tion of pure oxygen is unsuitable (ex-
plosion hazard!).





© ISF 2002
gap
preparations
denotation
sym-
bol
plate thickness
range s [mm]
from to
1,5
1,0
1,0
4,0
3,0
12,0
1,0
8,0
1,0

8,0
1,0 8,0
flange weld
plain butt
weld
V - weld
corner weld
lap seam
fillet weld
1 - 2
1 - 2
Gap Shapes for Gas Welding
s
+
1
~
~
r =

s
br-er1-16.cdr
© ISF 2002
PA
PB
PF
PG
PC
PE
PD
butt-welded seams in

gravity position
gravity fillet welds
horizontal fillet welds
vertical fillet and butt welds
vertical-upwelding position
vertical-down position
horizontal on
vertical wall
overhead position
horizontal overhead position
Welding Positions I
br-er1-17.cdr
f
s
Figure 1.16
Figure 1.17
1. Gas Welding 12

A special type of autogene method is
flame-straightening, where specific lo-
cally applied flame heating allows for
shape correction of workpieces, Figure
1.20. Much experience is needed to
carry out flame straightening processes.
The basic principle of flame straightening
depends on locally applied heating in
connection with prevention of expansion.
This process causes the appearance of a
heated zone. During cooling, shrinking
forces are generated in the heated zone

and lead to the desired shape correction.

© ISF 2002
5. after welding: Removing the equipment from the tank
4. illumination and electric machines: max 42volt
3. second person for safety reasons
2. extraction unit, ventilation
1. requirement for a permission to enter
protective measures / safety precautions
Hazards through gas, fumes, explosive mixtures,
electric current
Safety in welding and cutting inside of
tanks and narrow rooms
br-er1-19e.cdr
Gas Welding in Tanks and
Narrow Rooms
© ISF 2002
welded parts
first warm up both
lateral plates, then belt
butt weld
3 to 5 heat sources
close to the weld-seam
double fillet weld
1,3 or 5 heat sources
Flame straightening
Flame Straightening
br-er1-20.cdr
© ISF 2002
br-er1-18.cdr

PA
PB
PC
PD
PE
PG
PF
Welding Positions II
Figure 1.18
Figure 1.19 Figure 1.20
2003

2.
Manual Metal Arc Welding
2. Manual Metal Arc Welding 13
Figure 2.1 describes the burn-off of a
covered stick electrode. The stick
electrode consists of a core wire with
a mineral covering. The welding arc
between the electrode and the work-
piece melts core wire and covering.
Droplets of the liquefied core wire mix
with the molten base material forming
weld metal while the molten covering
is forming slag which, due to its lower
density, solidifies on the weld pool.
The slag layer and gases which are
generated inside the arc protect the
metal during transfer and also the
weld pool from the detrimental influ-

ences of the surrounding atmosphere.



Covered stick elec-
trodes have re-
placed the initially
applied metal arc
and carbon arc
electrodes. The
covering has taken
on the functions
which are described
in Figure 2.2.





br-er2-01.cdr
ISF 2002
c
Weld Point
Figure 2.1
© ISF 2002
1. Conductivity of the arc plasma is improved by
2. Constitution of slag, to
3. Constitution of gas shielding atmosphere of
4. Desoxidation and alloying of the weld metal
5. Additional input of metallic particles

a) ease of ignition
b) increase of arc stability
a) influence the transferred metal droplet
b) shield the droplet and the weld pool
against atmosphere
c) form weld bead
a) organic components
b) carbides
Task of Electrode Coating
br-er2-02.cdr
Figure 2.2
2. Manual Metal Arc Welding 14
The covering of the stick electrode consists of a multitude of components which are
mainly mineral, Figure 2.3.














For the stick electrode manufacturing mixed ground and screened covering mate-
rials are used as protection for the core wire which has been drawn to finished di-

ameter and subsequently cut to size, Figure 2.4.















© ISF 2002
Influence of the Coating Constituents
on Welding Characteristics
br-er2-03.cdr
coating raw material effect on the welding characteristics
quartz - SiO
2
to raise current-carrying capacity
rutile -TiO
2
to increase slag viscosity,
good re-striking
magnetite - FeO
34

to refine transfer of droplets through the arc
calcareous spar -CaCO
3
to reduce arc voltage, shielding gas
emitter and slag formation
fluorspar - CaF
2
to increase slag viscosity of basic electrodes,
decrease ionization
calcareous- fluorspar -
KO AlO 6SiO
2232
easy to ionize,
to improve arc stability
ferro-manganese / ferro-silicon
deoxidant
cellulose
shielding gas emitter
kaolin -
AlO 2SiO 2HO
2322
lubricant
potassium water glass
KSiO / NaSiO
2323
bonding agent
Figure 2.3
1
2
3

raw wire
storage
wire drawing machine
and cutting system
inspection
to the
pressing
plant
electrode
compound
raw material storage
for flux production
jaw
crusher
magnetic
separation
cone crusher
for pulverisation
sieving
to further treatment like milling,
sieving, cleaning and weighing
sieving system
weighing
and
mixing
inspection
wet mixer
descaling
inspection
example of a three-stage wire drawing machine

drawing plate
Ø 6 mm
Ø 5,5 mm
3,25 mm
Ø 4 mm
© ISF 2002
Stick Electrode Fabrication 1
br-er2-04.cdr
Figure 2.4
2. Manual Metal Arc Welding 15














The core wires are coated with the
covering material which contains bind-
ing agents in electrode extrusion
presses. The defect-free electrodes
then pass through a drying oven and
are, after a final inspection, automati-

cally packed, Figure 2.5.

Figure 2.6 shows how the moist ex-
truded covering is deposited onto the
core wire inside an electrode extrusion
press.








Stick Electrode Fabrication 2
© ISF 2002
br-er10-33e.cdr
core wire
maga-
zine
electrode
compound
inspection
inspection
inspection
inspection
inspection
the pressing plant
drying stove
TO

DELIVERY
packing
inspection
electrode-
press
compound
nozzle
convey-
ing
belt
wire
magazine
wire
feeder
pressing
head
Figure 2.5
core rod
coating
pressing nozzle
pressing cylinder
pressing cylinder
pressing mass
core rod guide
Production of Stick Electrodes
br-er2-06.cdr
Figure 2.6
2. Manual Metal Arc Welding 16
Stick electrodes are, according to their covering compositions, categorized into
four different types, Figure 2.7. with concern to burn-off characteristics and achiev-

able weld metal toughness these types show fundamental differences.















The melting characteristics of the different coverings and the slag properties result in
further properties; these determine the areas of application, Figure 2.8.

© ISF 2002
Characteristic Features of
Different Coating Types
br-er2-07.cdr
cellulosic type acid type rutile type
basic typ
cellulose
rutile
quartz
Fe - Mn
potassium water glass
40
20
25
15
magnetite
quartz
calcite
Fe - Mn
potassium water glass
50
20
10
20
rutile
magnetite
quartz
calcite

Fe - Mn
potassium water glass
TiO
2
SiO
2
FeO
SiO
CaCO
34
2
3
TiO
FeO
SiO
CaCO
2
34
2
3
fluorspar
calcite
quartz
Fe - Mn
potassium water glass
45
10
20
10
15

45
40
10
5
CaF
CaCO
SiO
2
3
2
almost
no slag
slag solidification
time: long
slag solidification
time: medium
slag solidification
time: short
droplet transfer :
toughness value:
medium- sized
droplets
good normal good very good
fine droplets
to sprinkle
medium- sized to
fine droplets
medium- sized to
big droplets
droplet transfer :

droplet transfer :
droplet transfer :
toughness value:
toughness value:
toughness value:
Figure 2.7
© ISF 2002
Characteristics of
Different Coating Types
br-er2-08.cdr
coating type
symbol
gap bridging
ability
current type/polarity
welding positions
sensitivity of
cold cracking
weld appearance
slag
detachability
characteristic
features
cellulosic type
C
acid type
A
rutile type
R
basic type

B
very good moderate good good
PG,(PA,PB,
PC,PE,PF)
PA,PB,PC,
PE,PF,PG
PA,PB,PC,
PE,PF,(PG)
PA,PB,PC,
PE,PF,PG
low
high
low very low
moderate
good good
moderate
good very good very good moderate
spatter,
little slag,
intensive fume
formation
high burn-out
losses
universal
application
low burn-out
losses
hygroscopic
predrying!!
~ / +

~ / +
~ / +
= / +
Figure 2.8
2. Manual Metal Arc Welding 17
The dependence on temperature of the slag’s electrical conductivity determines
the reignition behaviour of a stick electrode, Figure 2.9. The electrical conductivity for
a rutile stick elec-
trode lies, also at
room temperature,
above the thresh-
old value which is
necessary for reig-
nition. Therefore,
rutile electrodes
are given prefer-
ence in the
production of tack
welds where reig-
nition occurs fre-
quently.
The complete des-
ignation for filler
materials, following
European Stan-
dardisation, in-
cludes details–
partly as encoded
abbreviation –
which are relevant

for welding, Figure
2.10. The identifica-
tion letter for the
welding process is
first:
E - manual electrode welding G - gas metal arc welding
T - flux cored arc welding W - tungsten inert gas welding
S - submerged arc welding

© ISF 2002
Conductivity of Slags
br-er2-09.cdr
cond
u
c
t
i
v
i
t
y
temperature
reignition
threshold
h
i
g
h

r

u
t
i
l
e
-
c
o
n
t
a
i
n
i
n
g

s
l
a
g
s
e
m
i
c
o
n
d
u

c
t
o
r
ac
i
d

sla
g
hig
h-t
e
mpe
r
atu
r
e
condu
c
tor
b
a
s
i
c

s
l
a

g
h
i
g
h
-
t
e
m
p
e
r
a
t
u
r
e
c
o
n
d
u
c
t
o
r
Figure 2.9
© ISF 2002
Designation Example
for Stick Electrodes

br-er2-10.cdr
The mandatory part of the standard designation is: EN 499 - E 46 3 1Ni B
hydrogen content < 5 cm/100 g welding deposit
butt weld: gravity position
fillet weld: gravity position
suitable for direct and alternating current
recovery between 125% and 160%
basic thick-coated electrode
chemical composition 1,4% Mn and approx. 1% Ni
minimum impact 47 J in -30C
minimum weld metal deposit yield strength: 460 N/mm
distinguishing letter for manual electrode stick welding
3
o
2
DIN EN 499 - E 46 3 1Ni B 5 4 H5
Figure 2.10
2. Manual Metal Arc Welding 18
The identification numbers give information about yield point, tensile strength and
elongation of the weld metal where the tenfold of the identification number is the
minimum yield point in N/mm², Figure 2.11.

The identification figures for the minimum impact energy value of 47 J – a parame-
ter for the weld metal toughness – are shown in Figure 2.12.














© ISF 2002
Characteristic Key Numbers of Yield Strength,
Tensile Strength and Elongation
br-er2-11.cdr
key number minimum yield strength
N/mm
2
tensile strength
N/mm

2
minimum elongation*)
%
35
38
42
46
50
355
380
420
460
500
440-570
470-600
500-640
530-680
560-720
22
20
20
20
18
*) L= 5 D
0 0
Characteristic Key Numbers
for Impact Energy
br-er2-12.cdr
characteristic figure
minimum impact energy 47 J [C]

0
no demands
+20
0
-20
-30
-40
-50
-60
-70
-80
Z
A
0
2
3
4
5
6
7
8
The minimum value of the impact energy allocated to the characteristic
figures is the average value of three ISO-V-Specimen, the lowest
value of whitch amounts to 32 Joule.
Figure 2.11
Figure 2.12
2. Manual Metal Arc Welding 19
The chemical
composition of
the weld metal is

shown by the alloy
symbol, Figure
2.13.








The properties of a stick electrode are
characterised by the covering thick-
ness and the covering type. Both de-
tails are determined by the identifica-
tion letter for the electrode covering,
Figure 2.14.

© ISF 2002
Alloy Symbols for Weld Metals
Minimum Yield Strength up to 500 N/mm
2
br-er2-13.cdr
© ISF 2002
br-er2-14.cdr
key letter
type of coating
A
B
acid coating
basic coating
C
cellulose coating
R rutile coated
(medium thick)
RR
rutile coated (thick)
RA rutile acid coating
RB rutile basic coating
RC
rutile cellulose coating
Figure 2.13
Figure 2.14
2. Manual Metal Arc Welding 20
Figure 2.15 ex-
plains the additional
identification figure

for electrode recov-
ery and applicable
type of current.
The subsequent
identification figure
determines the ap-
plication possibili-
ties for different
welding positions:

1- all positions
2- all positions, except vertical down position
3- flat position butt weld, flat position fillet weld, horizontal-, vertical up position
4- flat position butt and fillet weld
5- as 3; and recommended for vertical down position

The last detail of the European Standard designation determines the maximum hy-
drogen content of the weld metal in cm³ per 100 g weld metal.
Welding current
amperage and
core wire diame-
ter of the stick
electrode are de-
termined by the
thickness of the
workpiece to be
welded. Fixed stick
electrode lengths
are assigned to
each diameter,

Figure 2.16.
© ISF 2002
Additional Characteristic Numbers
for Deposition Efficiency and Current Type
br-er2-15.cdr
Figure 2.15
© ISF 2002
Size and Welding Current
of Stick Electrodes
br-er2-16.cdr
Figure 2.16