This document discusses flux cored arc welding (FCAW), including its basic principles, types of wires and fluxes used, key variables that influence the process, and advantages over other welding processes like gas metal arc welding (GMAW) and shielded metal arc welding (SMAW). FCAW uses wire that contains a flux allowing it to operate with or without an external shielding gas. It offers higher deposition rates, faster travel speeds, and all-position welding capabilities compared to other processes.
This document discusses flux cored arc welding (FCAW), including its basic principles, types of wires and fluxes used, key variables that influence the process, and advantages over other welding processes like gas metal arc welding (GMAW) and shielded metal arc welding (SMAW). FCAW uses wire that contains a flux allowing it to operate with or without an external shielding gas. It offers higher deposition rates, faster travel speeds, and all-position welding capabilities compared to other processes.
This document discusses flux cored arc welding (FCAW), including its basic principles, types of wires and fluxes used, key variables that influence the process, and advantages over other welding processes like gas metal arc welding (GMAW) and shielded metal arc welding (SMAW). FCAW uses wire that contains a flux allowing it to operate with or without an external shielding gas. It offers higher deposition rates, faster travel speeds, and all-position welding capabilities compared to other processes.
This document discusses flux cored arc welding (FCAW), including its basic principles, types of wires and fluxes used, key variables that influence the process, and advantages over other welding processes like gas metal arc welding (GMAW) and shielded metal arc welding (SMAW). FCAW uses wire that contains a flux allowing it to operate with or without an external shielding gas. It offers higher deposition rates, faster travel speeds, and all-position welding capabilities compared to other processes.
Welding Research Institute 16-06-2012 Arc Characteristics lines Voltage ( Volts )
Power Source CV Line
Current ( Amp )
16-06- 9 Welding Research Institute 2012 FCAW consumable & Selection Criteria 10
Chemical & Mechanical Properties
Commercial Availability of Product
Hydrogen Level in the Weld Metal
Type of Shielding gas to be used
Cost Factor Welding Research Institute 16-06-2012 FCAW Wires 11
U Shaped sheet
Seamless Tube
Welding Research Institute 16-06-2012
FCAW Wires 12
Seamless Tube
Butt Lap Heart
Welding Research Institute 16-06-2012
Manufacturing Process of Seamless tube 13
Filling the flux by vibratory means into seamless
tube Predetermine quantity of flux is filled into the tube of specific ID and OD After filling, the tube is drawn to the required size Seamless tube is leak proof and hence the wire can be copper coated without danger of flux contamination No moisture pick up Welding Research Institute 16-06-2012 Manufacturing of U shaped wire 14
Steel Strip
U Shaped Roles
Flux Feeling
Closing Roles
To Drawing Operation Welding Research Institute 16-06-2012 Manufacturing Operation 15
Welding Research Institute 16-06-2012
Function of Flux 16
• De-Oxydizers & De-Nitriders
• Slag Formers
• Arc Stabilizers
• Alloying elements
• Gas Formers.
Welding Research Institute 16-06-2012
Function of flux ingradients 17
Deoxidizers and De-nitriders.
Since Oxygen and Nitrogen can cause porosity or brittleness, deoxidizers such as manganese and silicon are added. It helps to purify the weld metals
Slag Former Calcium, Potassium, silicon or sodium are added to protect the weld metal puddle from atmosphere. The slag aids in improving the weld bead shape, fast freezing & welding out of welding position
Welding Research Institute 16-06-2012
Function of flux ingredients 18
Arc Stablizers. Element such as Potassium and sodium helps to produce a smother arc and reduced spatter Alloying elements Element such as molybdenum, chromium, carbon, manganese, nickel and vanadium are uses to increase strength, ductility, hardness and toughness Gasifiers Minerals, such as flurospar (calcium fluoride) and limestone, are usually used to form a shielding gas
Welding Research Institute 16-06-2012
Types of Flux 19
Rutile Basic
Welding Research Institute 16-06-2012
Rutile Flux 20
Smooth arc
Fluid weld metal
Wide parameter zone
Attractive weld appearance (Shiny weld bead)
Welding Research Institute 16-06-2012
Basic Flux 21
Relatively clean weldmetal.
Low weldmetal hydrogen level
Good low temperature toughness
Less fluid weld metal
Welding Research Institute 16-06-2012
Shielding Gas 22
Carbon dioxide is most widely used.
Low Cost Deep Penetration
Agron-Carbon dioxide mixed gas
Better arc characteristic Mostly used in out of welding position
Welding Research Institute 16-06-2012
Process Variables 23
Welding Current
Arc Voltage Electrode
Extension
Travel Shielding Speed Gas & Flow Welding Research Institute 16-06-2012 Welding Current 24
Increasing current increasing electrode deposition rate
Increasing current increasing weld penetration
Excessive current produce convex weld bead with poor
appearance
Insufficient current produce large droplet and excessive
spatter
Welding Research Institute 16-06-2012
Arc Voltage 25
Arc Voltage and Arc Length are closely related to
each other.
Too high the arc voltage -Too long an arc length
The un melted Electrode that extents beyond the contact
tube during welding
Too long electrode extension produce an un stable arc
with excessive spatter
Too short electrode extension result in excessive spatter
build up in the nozzle that can interface with the gas flow (recommended value 19 to 38 mm)
Welding Research Institute 16-06-2012
Travel Speed 27
Travel Seed influence weld bead penetration and
weld contour
Too low travel speed at higher current cause over
heating of the weld metal
Too high travel speed will result in irregular, ropy
appearance
Welding Research Institute 16-06-2012
Shielding Gas Flow rate 28
Inadequate flow will result in poor shielding of
transferring filler metal and resulting weld porosity
Excessive gas flow rate result turbulence and mixing
with air, the result will be same as inadequate flow rate
Welding Research Institute 16-06-2012
FCAW Advantage 29
6 DEPOSITION RATE ( Kg/Hr )
FCAW 1.2 mm
2 GMAW ( 1.2 mm )
SMAW 4.0 mm
0 75 125 150 200 250
CURRENT (A) Welding Research Institute 16-06-2012 FCAW Advantage 30
• Requires external shielding gas.
• Higher deposition rate. • Faster travel speed. • Less sensitive to side wind. • Higher productivity. • All position welding capability. • Works at a higher current even in overhead position. • Higher deposition efficiency ( 85 - 90%). • Deep penetration.
Welding Research Institute 16-06-2012
Advantage of FCAW over SMAW 31
• INCREASE IN PRODUCTIVITY.
• SMALL NUMBER OF WIRE SIZES NEEDED.
• EQUALLY GOOD MECHANICAL PROPERTIES.
• GOOD WELDABILITY.
• LOW WELDMETAL HYDROGEN CONTENT.
• NO REBAKING.
Welding Research Institute 16-06-2012
Advantage of FCAW over GMAW 32
• REDUCED RISK OF FUSION DEFECTS.
• IMPROVED PENETRATION. • LESS SPATTER. • REDUCED SENSITIVITY TO POROSITY. • IMPROVED PRODUCTIVITY IN - POSITIONAL WELDING.
Welding Research Institute 16-06-2012
Electrode Classification 33
ELECTRODE
Min. Tensile Strength X 10,000 psi
0 : Flat and Horizontal Position
1: All Position EXX T - X Usability (Shielding Gas requirement) Performance (Polarity) Impact
Tubular or Flux Cored
Welding Research Institute 16-06-2012
Classification of SS FCAW Electrode 34
E - Electrode
XXX – 3 digit no. stands
for various material combination
EXXX T-1 1,2 – Stands for Shielding gas
Co2 and Ar +2% O2 respectively
T – Stands for Flux Cored
Electrode Welding Research Institute 16-06-2012 Self Shielded Flux Cored Arc Welding 35
Welding Research Institute 16-06-2012
Welding Torches 36
Welding Research Institute 16-06-2012
37
Welding Research Institute 16-06-2012
38
Welding Research Institute 16-06-2012
Advantage of SSFCAW 39
• Ideal for welding outdoors.
• Higher productivity than solid wire. • Good welds even on rusted plates. • Re-baking of wire not required. • All position welding capability. • Extensively used for pipeline construction. • No shielding gas is required. • Higher Electrode Extension (20-90 mm)
Welding Research Institute 16-06-2012
Troubleshooting 40
Problem Possible Cause Corrective Action
Porosity Low or High Gas Flow Increase or Decrease
Excessive wind draft Eliminate turbulence
Contaminated Gas or Base Metal or Proper inspection
filler wire Insufficient flux in core Change electrode
Excessive Voltage or Travel Speed Reset the Parameter
Improper stick out Set the correct stick out
Excessive Weaving Proper weaving
Welding Research Institute 16-06-2012
Troubleshooting 41
Problem Possible Cause Corrective Action
Incomplete Improper Manipulation Direct Electrode to joint
Fusion or root Penetration Improper Parameter Increase Current
