View
14
Download
3
Category
Preview:
Citation preview
Fundamental Welding Training Schedule
Version 2, 2017
Fundamental Welding Training Schedule
1. Welding Processes
Welding Processes mean the methods applied to weld, include MMA, MIG, TIG, Submerge
Arc, etc.
MMA Process
MMA mean manual metal arc welding, is an electric arc welding process in which the arc is
struck between welding electrode and workpiece. The central metal electrode or core wire
provide the filler metal for the weld. The electrode coating provides shielding of the weld
pool.
MMA process operate with an AC or DC power source, most commonly is DC.
MMA welding, only a limited amount of weld metal can be deposited from one electrode,
electrodes need to replaced frequently, making it a less productive process than other
welding process.
MMA metal application •Most carbon steel
•Stainless steel
•Cast iron
•Copper alloy
•Nickel alloy
•Aluminium alloy
MMA welding also used for hard surfacing, gouging, cutting of ferritic alloys.
1
MMA welding equipment The equipments used for MMA welding consists of:
•Power source ( ARC welding machine)
•Welding electrode
•electrode holder
•earth clamp
•electrode cable
•earth cable
MIG Process ( GMAW )
MIG process commonly refer to Metal Inert Gas, which a continuous wire is fed by powered
wire feeder into welding pool. An electric arc is created between contact tip of the wire and
the weld pool. Both arc and weld pool are protected by a shield of inert gas, delivered
through a shroud nozzle that is concentric with the wire.
MIG welding is usually carried out with a handheld torch as a semi-automatic process in
most mass engineering works, using solid wire, flux cored wire.
The shielding gas commonly as
•Argon
•Co2
•Argon and Co2 mixtures
MIG metal application •Most carbon steel
•Stainless steel
•Cast iron
•Copper alloy
•Nickel alloy
•Aluminium alloy
2
MIG welding equipment •Power source
•welding wire
•argon flow meter
•wire feeder
•MIG torch
•shielding gas
•earth cable
•earth clamp
TIG Process ( GTAW )
The Gas Tungsten Arc Welding, commonly refer to as Tungsten Inert Gas. This process uses
the heat generated by an electric arc struck between a tungsten electrode and workpiece to
fuse metal in the joint area and produce a molten weld pool.
TIG welding produce very high quality welds in wide range of materials, tends to be very
clean, producing very little fume and spatter.
TIG process is very versatile, can weld any metals or alloy system over a wide range of
thickness, but is usually restricted to 10mm and under.
TIG welding equipment •TIG power source
•TIG filler wire
•TIG torch
•argon flow meter
•earth clamp and cable
•shielding gas
3
Plasma Cutting Process
Plasma cutting uses the heat and pressure generated by a constricted electric arc to cut
material. DC power source is used. A pilot arc is maintained between the electrode and the
constricting orifice. The cutting process uses high plasma gas flows.
Plasma ca be used for a wide range of ferrous and non-ferrous metals.
Plasma cutting use air compressor as a source of air.
Cutting fume is generally high, the process tends to be noisy and high levels of radiation.
All these above mentioned welding processes are carried out with power source
(welding machine)
What is welding machine duty cycle?
Duty cycle is a welding machine specification which defines the number of minutes, within a
10 minutes period, during which this welding machine can safely produce a particular
welding current continuously.
For example, a 200A welding machine with a 60% duty cycle must be “rested” for at least 4
minutes after 6 minutes of continuous welding at 200A current.
The latest IGBT module technology can carry out 100% duty cycle which used in following
Pinnacle welding equipments:
4
PRIMIARC 201VRD
PRIMIARC 323VRD
PRIMIARC 403VRD
PRIMIARC 503VRD
PRIMICUT 60
PRIMICUT 100
PRIMICUT 120
PRIMITIG AC/DC 200P
PRIMITIG AC/DC 315P
2. Fundamentals of Manual Metal Arc (MMA) Welding
MMA also named ARC welding, which use electrode and electrode holder to weld with ARC
welding machine.
The following ARC welding machines are available from Pinnacle:
INTRUARC 161 220V 160A for DIY use
INTRUARC 200 220V 200A for DIY use
INTRUARC 210HD 220V 200A for DIY use, 80% duty cycle, generator friendly
PRIMIARC 201VRD 220V 200A, for industrial and mining use
PRIMIARC 323VRD 380V 300A, for industrial and mining use
PRIMIARC 403VRD 380V 400A, for industrial and mining use
PRIMIARC 503VRD 380V 500A, for industrial and mining use
Successful MMA welding depends on the following factors:
•Selection of correct electrodes
•Selection of correct size of electrode for the job
•Correct welding current
•Correct Arc length
•Correct angle of electrode to work
•Correct welding travel speed
•Correct preparation of work to be welded
Electrode selection
As a general, the selection of electrode is a matter of selecting an electrode of similar
composition to the parent mental. Often, one electrode in the group will be more suitable
for general application due to its all round qualities.
For example, the average welder will carry out most fabrication using mild steel plates, and
for this material has a choice of Pinnacle electrodes. Each of which will have qualities suited
to particular tasks.
5
The table below, shows just popular electrodes from Pinnacle for welding carbon steel in
typical areas of application.
CHISA SUPER 7 General Purpose
AWS E6013 A quality electrode for general purpose use, weld structural and sheet metal in all positions.
CITOX 7018-1 Low Hydrogen
AWS E7018-1 A quality, all positional hydrogen-controlled electrode for pressure vessel applications and where high integrity welding is required
CHISA SH E7024 Iron Powder
AWS E7024 An iron power electrode for high speed welding for medium and heavy structural application.
Electrode Size
The size of electrode generally depends on the thickness of the plate being welded, and the
thicker the plate the larger the electrode required. In the case of the light sheet, the
electrode size used is generally slightly larger than the work being welded. This mean that, if
2.0mm sheet is being welded, 2.5mm electrode is recommended size.
The following table gives the maximum size of electrodes that may be used for various
thickness of sheet.
Average Thickness of Sheet or section (mm)
Max recommended electrode size
1.5-2.0mm 2.5mm
2.0-5.0mm 3.2mm
5.0-8.0mm 4.0mm
>=8.0mm 5.0mm
In DIY market, the 2.5mm E6013 is most common seller. Takes 70-80% of total general
purpose welding electrode market.
Welding Current
Correct current selection for a particular job is an important factor in ARC welding. Weld
with current set too low, difficulty is experienced in striking and maintaining a stable arc.
The electrode tends to stick to the metal, penetration is poor.
Excessive current is accompanied by overheating of the electrode. It will cause undercut and
burning through of the material, and will give excessive spatter. ( the current specified on
the electrode package is considered to be the optimum )
6
Generally Recommended current for PINNACLE SUPER 7 E6013
Electrode Size (mm) Current Range (A)
2.5mm 90-110
3.2mm 125-145
4.0mm 130-195
5.0mm 165-250
ARC Length
To strike the arc, the electrode should be gently scratched on the work until the arc is
established. There is a simple rule for proper arc length; it should be shortest arc that gives a
good surface to the weld. An arc too long reduces penetration, produces spatter and gives a
rough surface finish. An excessively short arc will cause sticking of electrode and rough
deposit associated with slag inclusion.
Electrode Angle
The angle that the electrode makes with the work is important to ensure smooth, even
transfer of metal.
Generally, 70-85° is recommended.
Correct Welding Travel Speed
Correct travel speed for normal welding applications varies between 100-300mm per
minute, depending on electrodes size, size of run required and amperage used.
Excessive travel speed lead to poor fusion, lack of penetration, etc. While too slow will lead
to arc instability, slag infusion and poor mechanical properties.
Run Length per Electrode – PINNACLE SUPER 7 E6013
Electrode Size(mm) Electrode Length(mm) Min Run Length Max Run Length
2.5mm 350mm 100mm 225mm
3.2mm 350mm 125mm 225mm
4.0mm 350mm 175mm 300mm
Correct Work Preparation
Work to be welded need to be clean, grease-free. Poor condition workpiece will cause varies
welding defects like excessive smoke, spatter, porosity etc.
7
The chat below shows different effects of welding quality
Welding Defects and Problems
MMA welding, like other welding process, has welding procedure problems that may
develop and may cause defects in weld. Some defects are caused by problems with the
materials. A poor welding technique and improper choice of welding parameters can cause
weld defects as well.
Defects that can occur are slag inclusion, wagon tracks, porosity, wormhole porosity,
undercutting, lack of fusion, overlapping, burn through, cracks etc.
8
Welding Position
The following symbol show different welding position
Electrode Coating Types
MMA Electrodes, with a solid core wire, are generally categorised by the type of flux coating.
There are 3 main groups of electrode coating: rutile, basic and cellulosic.
Rutile type electrodes can weld on both AC and DC currents and weld in all positions.
Rutile type of electrodes are often referred to as general purpose electrodes like PINNACLE
SUPER 7 E6013.
Basic type of electrodes are capable of welding on AC or DC currents. Can weld all position.
Are often referred low hydrogen electrode of E7018-1
Cellulosic electrodes are mostly weld only on DC + polarity, are often referred to E6010,
E7010 for pipe welding.
3. Fundamentals of Metal Inert Gas (MIG) Welding
MIG welding use MIG wire and MIG torch weld with MIG power source. Generally used in
mass production, can weld continuously, more efficient than MMA welding.
The following MIG welding machines are available from Pinnacle:
PRIMIMIG 251C Compact 220V 250A, welds up to 1.0mm
PRIMIMIG 360C Compact 380V 315A, welds up to 1.2mm
PRIMIMIG 420S Separate Wire Feeder 380V 350A, welds up to 1.2mm
PRIMIMIG 520S Separate Wire Feeder 380V 500A, welds up to 1.6mm
9
The following MIG wire size available from Pinnacle:
0.6mm 5kg spool
0.8mm 5kg spool
0.8mm, 0.9mm,1.0mm,1.2mm,1.6mm 15kg spool
The Following MIG torch available from Pinnacle:
MB15 4M
MB25 4M
MB36 4M
MB40 4M
MB501 4M Water cooled torch
Successful MIG welding depends on the following factors:
•selection of correct consumables
•Selection of correct power source
•Selection of correct shielding gas
•selection of correct welding techniques:
Correct angle of wire to work
Correct wire stick out
Correct travel speed
•Selection of the welding preparation
•Selection of correct Mig wire
As a general rule, the selection of wire is simple, only a matter of selection a wire of similar
composition the parent metal.
Surface condition
The welding wire must be free from any surface contamination, include mechanical damage
such as scratch marks.
A simple test for checking the surface condition is to run the wire through a cloth that has
been dampened with acetone. If black residue is found on the cloth, the surface of the wire
is not properly cleaned.
Cast and Helix
The cast and helix of the wire has a major influence on the feedability of MIG wire.
10
Cast – Diameter of the circle
Helix – Vertical height
If the cast is too small, the wire will dip down from the tip. The result of this is excessive tip
wear and increased wear in the liners.
If the helix is too large, the wire will leave the contact tip with a corkscrew effect and cause
feeding problem.
Selection of Correct Power Source
Power source for MIG/MAG welding is selected on a number of different criteria, including:
•Maximum output of the machines
•Duty cycle
•Output control ( Voltage selection, wire feed speed control )
•Portability
The following table gives an indication of the welding amperage for different sizes wires:
Wire Size (mm) Amperage range (A)
0.8mm 60-180A
0.9mm 70-250A
1.0mm 90-280A
1.2mm 120-340A
Selection of Correct Shielding Gas
The selection of the shielding gas has a direct influence on the appearance and quality of the
weldbead.
The type and thickness of the material to be welded will determine the type of shielding gas
selected.
As a general rule, the thicker the material, the higher percentage of CO2 in the shielding gas
mixture.
The pure CO2 and CO2 75% Argon 25% mixture gas are most common shielding gas.
4. Fundamentals of Tungsten Inert Gas (TIG) welding
The following TIG welding machines are available from Pinnacle:
11
PRIMITIG 200 DC 220V 200A without pulse
PRIMITIG 200P DC 220V 200A with pulse
PRIMITIG AC/DC 200P 220V 200A with pulse, special for aluminium TIG pulse welding
PRIMITIG AC/DC 315P 380V 315A with pulse, special for aluminium TIG pulse welding
The following TIG torches are available from Pinnacle:
WP-17V 4M
WP-26V 4M
WP-26V 8M
WP-18V 8M water cooled
Tungsten Electrode colour tip identification:
Most widely used tungsten electrodes are red and white tip
Red Tip, Thoriated Tungsten Electrode, use for carbon and stainless steel, nickel alloys
White Tip, Zirconiated Tungsten Electrode, use for aluminium and magnesium alloy
5. Fundamentals of Brazing (Oxy-fuel welding )
12
Braze welding use a flame to heat the plate and add filler material. Take place at
temperatures above 450°C, but below the melting point of the base metal.
An advantage of braze welding is reduced distortion because of the lower temperatures.
A flux, either coated on or contained within the rod, or in the bottle must chemically clean
the surface of the parent metal during heating.
6. Welding of Stainless Steel
Stainless steels are a group of high alloy steels, which contain at least 12% chromium. These
steels are alloyed with a number of other elements like nickel, molybdenum etc, which make
them resistant to a variety of different environments like rust corrosion etc.
Stainless steel welding consumables have electrode, MIG wire, TIG wire forms.
See attached chart for most common stainless steel electrodes
7. Welding of Hard Surfacing
Hard Surfacing is the deposit of a special alloy material on metallic part to obtain more
desirable wear properties, which usually sought are greater resistance to wear from
abrasion, impact, adhesion (metal to metal ), heat, corrosion.
Pinnacle provides following types of hard surfacing electrode and wire as below:
SUPERCLAD 667A electrode, HRC 50-55, impact & abrasive, machineable
SUPERCLAD 667B electrode, HRC55-60, abrasive, non-machineable
SUGAR 80 electrode, designed for sugar mill roller
SUGAR 100 electrode, designed for sugar mill hammer
CLADCOR 50 flux cored wire, HRC 50-55, impact & abrasives, machineable
CLADCOR 60 flux cored wire, HRC 55-60, abrasives, non-machineable
13
MMA Electrodes for Stainless Steel
and Heat Resistant Steel
AWS/ASME Classification
Application Chemical Analysis %
C Mn Si Cr Ni Mo
Stainarc E308L-16
Rutile type electrode for 304,304L,308L, 321 &347 type steels. AC/DC+
0.03 0.7 0.8 19 9.8
Stainarc E316L-16
Rutile type CrNiMo electrode for 316 and 316L stainless steel. AC/DC+
0.03 0.6 0.8 18 12 2.6
Stainarc E309L-16
Rutile type electrode for joining stainless to carbon steels and type of 309 and 309S. AC/DC+
0.03 0.7 0.8 24 13
Stainarc E310-16
Basic electrode for 25/20 CrNi type steels such as 309 & 310. AC/DC+
0.10 1.2 0.7 25 20
Stainarc E312
Crack resistant electrode for dissimilar steels AC/DC+
0.12 1.0 0.9 29 9
Stainarc E2209
Rutile type electrode for SAF 2205 and similar duplex Steels. AC/DC+
0.04 0.9 0.8 22 8 3
Stainarc E307-16
High recovery electrode for dissimilar steel and joining 14% Mn steels. AC/DC+
0.07 0.6 5.5 20 8 1
MMA Electrodes for Cast Iron
AWS/ASME Classification
Application Hardness UTS (Mpa)
Supercast 55 E NiFe-Cl
Nickel-Iron electrode for nodular cast iron, meehanite and welds between cast iron and steel. AC/DC-
220HB 450
Supercast 99 E Ni-Cl
Nickel electrode for cast iron when full machineability is required. AC/DC+
160HB 400
MMA Electrodes for Aluminium Alloys
AWS/ASME Classification
Application Analysis % UTS (Mpa)
ALSI12 Al-Si electrode for welding aluminium alloys
Al---88.5 Si---11.5
190
MMA Electrodes for Cutting & Gouging
AWS/ASME Classification
Application
Super Power Gouge Electrode for cutting and gouging of steel, cast iron and non-ferrous metals.
MMA Electrodes for Hardfacing and
Surfacing
AWS/ASME Classification
Application Chemical Analysis %
C Mn Si Cr
Superclad D667A
Metal carbide deposit withstand impact at medium loads and abrasives. The hardness approximately 550HV (HRC 50-55)
3.5 1.5 1.0 28.0 min
Superclad D667B
Specially designed for wear resistant application. Can withstand impact under relatively abrasive conditions. HRC55-60
4.0 2.0 1.0 30.0 min
Sugarc 80 Specially designed for hardfacing for sugar mill roller
4.0 1.8 1.0 26.0 min
Sugarc 100 Specially designed for hardfacing for sugar mill hammer
3.0 1.6 1.0 28.0 min
Submerged Arc Wire & Flux
AWS A5.17 DIN 8557 EN 756
EM12K S2 S2
Flux Type Composition Operation SJ501 Agglomerated Fluoride-Basic (FB) DC+/AC
HJ107 Agglomerated Basic(FB) DC+
GMAW(MIG/MAG) Wire Summary and
Classifications
Material Brand Name AWS/ASME Classification
Mild Steel XTRAWELD 2 A5.18 ER70S-6
Low Alloy Steel XTRAWELD 648 A5.28 ER100S-G
Stainless Steel STAINLUX 316LSi A5.9 ER316LSi
STAINLUX 308LSi A5.9 ER308LSi STAINLUX 309LSi A5.9 ER309LSi
STAINLUX 307Si A5.9 ER307 (nearest)
STAINLUX 410 A5.9 ER410
STAINLUX 2209 A5.9 ER2209 STAINLUX 310 A5.9 ER310
STAINLUX 312 A5.9 ER312
Aluminium Alloys ALUWELD 4043 A5.10 ER4043
ALUWELD 5356 A5.10 ER5356 ALUWELD 1100 A5.10 ER1100
Cast Iron MIG Ni 99 A5.15 ENi-Cl
Non Ferrous Alloys SILICON BRONZE A5.7 ERCuSi-A ALU BRONZE A5.7 ERCuAl-A2
DEOXIDIZED COPPER A5.7 ERCu
GTAW(TIG) Wire Summary and Classifications
Material Brand Name AWS/ASME Classification
Mild steel TIGSTEEL 70 A5.18 ER70S-6
Stainless Steel STAINLUX 316L A5.9 ER316L
STAINLUX 308L A5.9 ER308L
STAINLUX 309L A5.9 ER309L
Aluminium Alloys ALUWELD 4043 A5.10 ER4043
ALUWELD 5356 A5.10 ER5356
ALUWELD 4047 A5.10 ER4047
Non Ferrous Alloys SILICON BRONZE A5.7 ERCuSi-A ALU BRONZE A5.7 ERCuAl-A2
FCW Wire Summary and Classifications
Material Brand Name Classification
Mild Steel XTRACOR 71 AWS A5.20 ER71T-1C
XTRACOR 71M AWS A5.20 ER71T-1M
XTRACOR 11 AWS A5.20 ER71T-11
Stainless Steel STAINCOR 316 AWS A5.22 E316LT1-1
STAINCOR 308 AWS A5.22 E308LT1-1
STAINCOR 309 AWS A5.22 E309LT1-1
Hardfacing CLADCOR 50 DIN8555 MSG 6-55
CLADCOR 60 DIN8555 MSG 6-60
Brazing Materials Summary and Classifications
Material Brand Name Classification
Bronze BBR AWS A5.27 RB CuZn-C
FLUX COATED BBR PINK AWS A5.27 RB CuZn-C
Silver
SILVERBRAZE 20 BARE DIN L-Ag20 SILVERBRAZE 30 BARE DIN L-Ag30
SILVERBRAZE 20F WHITE DIN L-Ag20
SILVERBRAZE 30F BLUE DIN L-Ag30/BS AG 16
SILVERBRAZE 40F YELLOW DIN L-Ag40/BS AG 20
Copper COPPERBRAZE 1 DIN 8513 L-Cu7P
COPPERBRAZE 2 DIN 8513 L-Ag2
Oxy-Fuel Gas Rod
Brand Name Classification
CCR AWS R45
Recommended