FCAW Applications 230

This class describes the FCAW process and the variables that affect electrode selection, shielding gas selection, and electrode orientation. Includes an Interactive Lab.

Class Details

Class Name:
FCAW Applications 230
Description:
This class describes the FCAW process and the variables that affect electrode selection, shielding gas selection, and electrode orientation. Includes an Interactive Lab.
Version:
1.0
Difficulty:
Intermediate
Number of Lessons:
21
Additional Language:
Spanish, Chinese
Related 2.0 Classes:
Introduction to FCAW 261, FCAW Applications 321

Class Outline

  • Objectives
  • What Is FCAW?
  • Pros and Cons of Self-Shielded FCAW
  • Pros and Cons of Gas-Shielded FCAW
  • Metals Welded with FCAW
  • FCAW Equipment
  • FCAW Guns
  • Self-Shielded FCAW Guns
  • Gas-Shielded FCAW Guns
  • FCAW Electrodes
  • FCAW Electrode Characteristics
  • FCAW Flux Materials
  • FCAW Shielding Gases
  • Amperage
  • Voltage
  • FCAW Electrode Orientation
  • FCAW Electrode Orientation Techniques
  • FCAW Joint Preparation
  • Starting the Arc
  • Running a FCAW Bead
  • Summary

Objectives

  • Define FCAW.
  • Distinguish self-shielded FCAW from other welding processes.
  • Distinguish gas-shielded FCAW from other welding processes.
  • Identify common metals welded with FCAW.
  • Explain characteristics of common FCAW equipment.
  • Describe the purpose of the contact tip.
  • Identify components of the self-shielded FCAW gun.
  • Identify components of the gas-shielded FCAW gun.
  • Describe how FCAW electrodes are made.
  • Describe how electrode extension affects the weld.
  • Describe the characteristics of flux materials.
  • Distinguish between common shielding gases for FCAW.
  • Describe FCAW amperage characteristics.
  • Describe the factors that affect voltage for FCAW.
  • Describe how flux affects electrode orientation.
  • Distinguish between common electrode orientation techniques.
  • Describe how both FCAW processes impact joint design.
  • Explain techniques for starting the arc with FCAW.
  • Explain how to run a weld bead using FCAW.

Certifications

AWS
  • AWS SENSE Level 1

Glossary

Vocabulary Term Definition
air-cooled gun A type of welding gun that has a small nozzle on the end, which provides air to cool the gun after welding. Air-cooled guns are often used with self-shielded electrodes.
aluminum A silvery white metal that is soft, light, and an effective conductor. Aluminum is the main deoxidizer in flux material.
amperage A measurement that indicates the amount of current flowing in a circuit, which is measured in amperes. FCAW amperage is determined by wire speed.
argon An inactive gas commonly used as shielding. Argon is much heavier than air, so it effectively shields the weld area.
automatic equipment Welding equipment which is controlled by settings on a computer or robot.
backhand technique Moving the electrode along the workpiece opposite the direction of welding. Self-shielded FCAW often uses the backhand technique.
bevel angle The angle formed between the prepared edge of one side of the base metal and a plane perpendicular to the surface of the other side of the base metal.
carbon dioxide An active gas commonly used as shielding for FCAW. Carbon dioxide is inexpensive but yields a violent arc.
carbon monoxide A colorless, odorless, poisonous gas made of carbon and oxygen.
carbon steel A steel that consists of iron and carbon, without any additional materials.
chromium A shiny, hard, steel-gray metal that increases the hardenability and corrosion resistance of steel. Stainless steels also contain large amounts of chromium.
constant voltage Welding using a voltage that varies slightly with changes in current, or amperage. Constant voltage, or CV, is often used for gas metal arc welding (GMAW) and flux-cored arc welding (FCAW).
contact tip The device located inside the welding gun that conducts electricity to the electrode. The contact tip is usually made of copper.
copper A reddish metal that is very ductile, thermally and electrically conductive, and corrosive resistant. Copper is often used to make electrical wire.
corrosion resistance A metal's ability to resist attack by other elements and chemicals.
crater An undesirable depression in the weld bead. A crater can cause cracking if it is not properly filled.
DCEN An abbreviation for direct current electrode negative. DCEN is another way of expressing direct current with straight polarity.
DCEP An abbreviation for direct current electrode positive. DCEP is another way of expressing direct current with reverse polarity.
deoxidizer A material that removes oxygen from the molten weld puddle and arc. Oxygen can ruin a weld bead.
deposition rate The rate at which an electrode melts into the molten weld puddle to form a weld.
drag angle A term used in industry for the backhand technique.
drawing dies Tools used to form wire or metal to a specified shape.
duty cycle The amount of time in a ten-minute period that an electrical device can perform work without overheating. If a welding gun has a 30% duty cycle, it can operate for three consecutive minutes and must rest for seven.
electrical stickout A term used to describe electrode extension, or the distance from the end of the contact tip to the end of the electrode.
electrode axis An imaginary line through the center of the electrode.
electrode diameter A measurement of the thickness of the electrode. FCAW uses a range of electrode diameters.
electrode extension The distance from the end of the contact tip to the end of the electrode.
electrode liner The insulated lining that surrounds the wire electrode and supports it from the wire feeder to the contact tip.
electrode orientation The position in which a welder manipulates the electrode. Electrode orientation refers to the work angle and the travel angle.
FCAW The American Welding Society abbreviation for flux-cored arc welding.
ferrous metal A metal that contains iron. Steel is the most popular ferrous metal.
flux A non-metallic material used to protect the weld puddle and solid metal from atmospheric contamination. In FCAW, flux material is contained in the core of the electrode.
flux-cored arc welding An arc welding process that uses a continuously fed consumable electrode that contains flux in a hollowed-out center. It is also referred to as FCAW.
forehand technique Moving the electrode along the workpiece in the direction of welding. Gas-shielded FCAW often uses the forehand technique.
gas diffuser The device inside the welding gun through which shielding gas flows.
gas mark A condition that occurs in gas-shielded FCAW that when a gas bubble from the arc does not escape through the molten slag and becomes trapped in the weld puddle. The slag solidifies, and the trapped gas bubble marks the weld bead. This is generally a visual defect but it can lead to physical defects.
gas metal arc welding An arc welding process in which a solid wire electrode and inert or active shielding gas are fed to the weld through a welding gun. It is also referred to as GMAW or MIG welding.
gas mixture A combination of gases used for shielding the weld. FCAW often uses an argon-carbon dioxide gas mixture.
gas nozzle The device placed directly over the welding gun that forces shielding gas to surround the electrode and arc.
gas regulation equipment Equipment that controls the delivery of shielding gas to the welding area.
gas-shielded FCAW A type of FCAW process that uses a tubular wire electrode filled with flux and an external shielding gas. Gas-shielded FCAW provides double shielding protection.
groove weld A type of weld that consists of an opening between two part surfaces, which provides space to contain weld metal. Groove welds are used on all joints except lap joints.
hydrogen cracking A weld defect that occurs in the weld metal when hydrogen comes into contact with a crack-susceptible weld. Low-hydrogen electrodes reduce hydrogen cracking.
insulated guide A small, non-conductive piece of material placed inside the welding gun to prevent the gas nozzle from becoming electrically charged.
insulated nozzle A type of nozzle used in gas-shielded FCAW guns that uses a piece of non-conductive material inside the gun to prevent the nozzle from becoming electrically charged.
joint design The specification of a particular joint type and its required dimensions.
joint preparation A variety of processes that prepares base metals before welding. This can involve preheating, cutting, or other preparations.
low-alloy steel A steel that contains small amounts of intentionally added materials, which change the property of the metal. Common alloy elements include manganese, molybdenum, and nickel.
mechanical properties The properties that describe a material's ability to compress, stretch, bend, scratch, dent, or break.
nickel A hard, malleable, silvery white metal often added to FCAW electrodes to increase strength and corrosion resistance.
physical properties The properties that describe a metal's ability to melt, emit heat, conduct electricity, and expand or shrink.
porosity Cavity type discontinuities or bubbles formed by gas entrapment during solidification of the weld metal.
push angle A term used in industry for the forehand technique.
root opening The separation at the joint root between the base metals. The size of the root opening determines how much weld metal is needed to obtain fusion at the root.
self-shielded FCAW A type of FCAW process that uses a tubular wire electrode filled with flux.
semi-automatic equipment Welding equipment that uses a welder and a manual welding gun. The weldor controls electrode orientation and travel speed.
shielded metal arc welding An arc welding process that uses a flux-coated rod as its electrode. It is also referred to as SMAW or stick welding.
slag inclusion Non-metallic solid material entrapped in weld metal or between weld metal and base metal.
slip-on nozzle A type of nozzle used on gas-shielded FCAW guns in which the insulator can come apart from the nozzle.
spray arc transfer A type of metal transfer in which the metal at the end of the wire melts into small, fine droplets creating a stable arc and little spatter.
stainless steel A type of steel that contains more than 15% chromium and exhibits excellent corrosion resistance.
stringer bead A type of weld bead formed by moving the electrode straight across the joint. A good stringer bead has good wash-in at the weld toes.
tensile strength A metal's ability to resist forces that attempt to pull apart or stretch it.
travel angle The angle less than 90 degrees between the electrode and the weld.
undercut A groove melted into the base material, usually along the toes of the weld, that produces a weak spot in the weld.
visible stickout The distance between the end of the gas nozzle and the end of the electrode. Visible stickout is the portion of the electrode that the welder can see.
voltage The electrical force or pressure that causes current to flow in a circuit.
wash-in The section of deposited weld metal that aligns evenly with the weld toe. A good wash-in is smooth and even along the joint and does not undertcut the base metal.
water-cooled gun A type of welding gun that uses water to cool the welding gun. Water-cooled guns often operate at a higher duty cycle than air-cooled guns.
weave bead A weld bead formed by moving the electrode along the joint in a weaving motion.
weld axis An imaginary line through the center and along the length of the weld.
weld pass One progression of welding across a joint. The result of a weld pass is a weld bead.
weld toe The point at which the weld face and the base metal meet.
welder Either the person who performs a weld or the power source that provides the electricity needed to perform an arc weld. Printed materials may use both meanings of the term.
welding gun An instrument used in some automatic and semi-automatic welding processes that conducts electricity, guides the electrode, and in some cases, releases shielding gas.
weldor A term sometimes used to refer to the person who welds.
wire feeder The device either built inside the welder or set beside the welder that feeds wire to the welding gun.
work angle The angle less than 90 degrees between a line perpendicular to the workpiece and a plane determined by the electrode axis and the weld axis. The work angle is used to center the weld bead on a given application.
worm tracking Another name for gas marks.
yield strength A metal's ability to resist gradual progressive force without permanent deformation.