What is the definition of "pulse arc transfer method"?
A type of metal transfer in which as little as one droplet of metal forms on the end of the electrode at a time. Pulse arc is the most precise transfer method.

Learn more about pulse arc transfer method in the class GMAW Applications 220 below.


Welding Training


Class Information
Tooling U-SME classes are offered at the beginner, intermediate, and advanced levels. The typical class consists of 12 to 25 lessons and will take approximately one hour to complete.
Class Name:GMAW Applications 220
Description:This class describes the GMAW process and the variables that affect shielding gas selection, electrode selection, metal transfer methods, and electrode orientation. Includes an Interactive Lab.
Prerequisites: 650110  650115  650130  650140<
Difficulty:Intermediate
Number of Lessons:21
Language:English, Spanish, Chinese
 
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Class Outline
  • Objectives
  • What Is GMAW?
  • Pros and Cons of GMAW
  • Metals Welded with GMAW
  • GMAW Equipment
  • GMAW Gun
  • GMAW Electrodes
  • Shielding Gas Characteristics
  • Types of Shielding Gas
  • Amperage
  • Voltage
  • GMAW Joint Preparation
  • Starting the Arc
  • Short Circuit Transfer Method
  • Globular Transfer Method
  • Spray Transfer Method
  • Pulse Arc Transfer Method
  • GMAW Electrode Orientation
  • GMAW Travel Speed
  • Running a GMAW Bead
  • Summary
  
Class Objectives
  • Define GMAW.
  • Distinguish GMAW from other welding processes.
  • Identify common metals welded with GMAW.
  • Explain characteristics of common GMAW equipment.
  • Identify components of the GMAW gun.
  • Identify common GMAW electrode materials.
  • Explain the function of shielding gas for GMAW.
  • Distinguish between common shielding gases used for GMAW.
  • Describe GMAW amperage characteristics.
  • Describe the factors that affect voltage for GMAW.
  • Describe common methods for preparing a joint for GMAW.
  • Explain techniques for starting the arc with GMAW.
  • Describe the short circuit metal transfer method.
  • Describe the globular metal transfer method.
  • Describe the spray metal transfer method.
  • Describe the pulse arc metal transfer method.
  • Distinguish between the methods of electrode orientation.
  • Explain the effects of travel speed on the GMAW process.
  • Explain how to run a weld bead using GMAW.

Class Vocabulary

Vocabulary TermDefinition
active gas A gas that reacts with other elements. GMAW uses both active and inactive gas as shielding.
alloy A metal consisting of a mixture of two or more materials. One of these materials must be a metal.
alloy steel A steel that contains intentionally added materials that change the property of the metal. Common alloy elements include manganese, molybdenum, and nickel.
aluminum A silvery white metal that is soft, light, and conductive. GMAW was originally created to weld aluminum.
American Welding Society The non-profit society that regulates the industrial standards for welding and promotes the welding industry.
amperage A measurement that indicates the amount of current flowing in a circuit, which is measured in amperes. GMAW 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.
backhand technique Moving the electrode along the workpiece opposite the direction of welding.
carbon dioxide An active gas commonly used as shielding for GMAW. Carbon dioxide is inexpensive but yields a violent arc.
carbon steel A steel that consists of iron and carbon, without any additional materials.
circuit A controlled path for electricity. All arc welding processes require a closed electrical circuit in which electricity can easily flow.
constant voltage welder A welding machine that maintains a constant voltage setting while compensating for changes in amperage.
consumable electrode An electrode that conducts electricity to the arc but also melts into the weld as a filler metal.
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 corrosion resistant.
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.
cylinder pressure gauge The device that indicates the amount of shielding gas present in the gas cylinder.
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.
directly proportional A constant ratio between two values. If value A increases, value B also increases. If value A decreases, then value B also decreases.
drag angle A term used in industry for the backhand technique.
ductility A metal's ability to be drawn, stretched, or formed without breaking.
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 resistance The opposition to current flow. Excessive stickout causes increased electrical resistance between the electrode and workpiece.
electrode axis An imaginary line through the center of the electrode.
electrode diameter A measurement of the thickness of the electrode. GMAW has the thinnest electrode diameters, which allows it to weld thin base metals.
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.
fast-freeze weld A weld that solidifies quickly. Fast freezing welds are more easily performed out-of-position, and they reduce the risk of a leaking weld puddle.
ferrous metal A metal that contains iron. Steel is the most popular ferrous metal.
filler metal Metal deposited into the weld that often adds strength and mass to the welded joint. The wire electrode for GMAW is the filler metal.
forehand technique Moving the electrode along the workpiece in the direction of welding.
gas cylinder An external device used to house shielding gas. Shielding gas flows from the gas cylinder, to the gas hose, to the welding gun.
gas diffuser The device inside the welding gun through which shielding gas flows.
gas metal arc welding An arc welding process in which a bare 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 nozzle The device placed directly over the welding gun that forces shielding gas to surround the electrode and arc.
globular transfer method A type of metal transfer in which the electrode produces a large ball of metal when it touches the workpiece. This deposits large amounts of metal into the weld puddle.
GMAW The American Welding Society abbreviation for gas metal arc welding.
helium An inactive gas commonly used as shielding for GMAW. Helium is much lighter than air and can escape the weld area quickly.
inert Something that is inactive and does not react with other elements. GMAW uses inert gas as shielding.
inert gas A type of gas that does not react with other elements. GMAW uses both inert gas and active gas as shielding.
insulator A small non-conductive piece of material placed inside the welding gun to prevent the gas nozzle from becoming electrically charged.
ipm An abbreviation for inches per minute. Ipm refers to the rate at which the wire electrode feeds through the welding gun.
joint preparation A variety of processes that prepare base metals before welding. This often includes preheating, cutting, or other preparations.
low-alloy steel A steel that contains small amounts of intentionally added materials that change the properties of the metal. Common alloy elements include manganese, molybdenum, and nickel.
low-carbon steel A steel that has a carbon range between 0.05 and 0.30%. Also referred to as mild steel.
manganese A hard, brittle, gray-white metal often added to GMAW electrodes. Manganese acts as a deoxidizer and increases strength and hardness in the weld.
metal transfer The way in which filler metal is deposited into a weld.
MIG welding Another name for gas metal arc welding or GMAW.
molybdenum A metallic alloying element often added to GMAW electrodes to increase strength and hardness without decreasing ductility.
nickel A hard, malleable, silvery white metal often added to GMAW electrodes to increase strength and hardness without decreasing ductility.
nonferrous metal A metal that does not contain iron. Aluminum and copper are common nonferrous metals.
oxidation A material's chemical reaction with oxygen. Oxidation can ruin a weld bead.
oxide scale A film that forms on metals like aluminum and carbon steels that must be removed before welding.
oxygen A colorless, odorless, tasteless gas that naturally exists in the atmosphere. A small amount of oxygen is sometimes used for shielding. However, too much oxygen causes cracking and rusting in the metals.
penetration The depth to which the arc heat can melt the joint below the surface of the base metals. The amount of amperage directly affects weld penetration.
porosity The appearance of tiny bubbles on a weld bead as a result of gas entrapment. Excessive porosity can weaken a weld.
preheating The application of heat to a base metal immediately before welding. Preheating helps reduce hardness in the metal.
pulse arc transfer method A type of metal transfer in which as little as one droplet of metal forms on the end of the electrode at a time. Pulse arc is the most precise transfer method.
push angle A term used in industry for the forehand technique.
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.
shielding gas A gas that protects the weld puddle and arc from reacting negatively with the atmosphere. GMAW shielding gas is supplied by a cylinder and flows through the welding gun.
shielding gas flowmeter The device that controls the amount of shielding gas that flows to the weld area.
short circuit An interruption in the intended flow of electricity, especially when current flows "short" of reaching a device. A short circuit causes excess current flow.
short circuit transfer method A type of metal transfer in which the electrode produces a short circuit and high current when it touches the workpiece. The high current level causes a violent transfer of metal, which creates the weld.
silicon A nonmetallic material often added to GMAW electrodes to act as a deoxidizer.
slag Cooled flux that forms on top of the weld bead. Slag protects cooling metal and is then chipped off. GMAW does not use flux, and as a result, does not have slag.
spatter Liquid metal droplets expelled from the welding process. Spatter can leave undesirable dots of metal on a workpiece surface.
spray transfer method 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.
stickout A term used to describe electrode extension, or the distance from the end of the contact tip to the end of the electrode.
stringer bead A type of weld bead formed by moving the electrode straight across the joint. A quality GMAW stringer bead has good wash-in at the toes of the weld.
tensile strength A metal's ability to resist forces that attempt to pull it apart or stretch it.
titanium A silvery white metal that has a high strength-to-weight ratio and corrosion resistance. Titanium is often used in aerospace applications.
transition current The current at which a consumable wire electrode goes from the globular transfer method to the spray transfer method.
travel angle The angle less than 90 degrees between the electrode and the weld.
trigger A lever on the welding gun. When a welder holds the gun above the workpiece and pulls the trigger, the welding process begins.
turbulence An upset in the even flow of shielding gas to the welding area. Turbulence causes gas to swirl, and as a result, mix with outside air. Turbulence is often the result of excessive shielding gas.
undercut A groove melted into the base material, usually along the toes of the weld, that produces a weak spot in the weld.
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 undercut the base metal.
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 backing A strip of metal located on the side opposite of the weld that provides a surface for depositing the first layer of metal to prevent molten metal from escaping through the joint. Weld backing is also sometimes used to protect the back of the weld from atmospheric contamination.
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.
weldability The ability of a material to be welded under imposed conditions into a specific, suitable structure and to perform satisfactorily for its intended use.
welding gun An instrument used in some automatic and semi-automatic welding processes that conducts electricity, guides the electrode, and releases shielding gas.
weldor A term sometimes used to refer to the person who welds.
wire electrode An electrode that is in the form of a wire. Wire electrodes are more productive than stick electrodes because they do not require frequent changing.
wire feed speed The rate at which the wire electrode is fed through the welding gun.
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.
work cable The path used in welding to conduct electricity from the welder to the workpiece. In welding, the cables are connected to the welder, the workpiece, and electrode, providing a closed electrical circuit.
work clamp The component that, along with the electrode, can come in direct contact with the workpiece during welding. The work clamp is connected to the welder by the work cable and provides ground for the GMAW circuit.