The essential guide

ROBOT WELDING

You are here: Reference / Dictionary of welding terms

Dictionary

Below is a list of technical terms, that are frequently used in the robotic welding industry.

Alternating current (AC) - An electrical current that reverses its direction at regular intervals, such as 60 cycles alternating current (AC), or 60 hertz.

Amperage - The measurement of the amount of electricity flowing past a given point in a conductor per second. Current is another name for amperage.

Arc - The physical gap between the end of the electrode and the base metal. The physical gap causes heat due to resistance of current flow and arc rays.

Arc-blow - Deflection of the arc by magnetic fields in the surrounding material.

Braze welding - Joining using a technique like fusion welding but with a filler material that has a lower melting point than the parent material.

Burnback - The fusion of the electrode wire to the contact tip. For robot welding it is critical to select an appropriate burnback at the end of the weld in order to avoid a weld error.

Burnoff rate - The rate at which a consumable electrode is consumed in an arc.

Cold Metal Transfer - “CMT” a welding process developed by Fronius which relies on the are being extinguished and reignited in rapid succession. It is ideally suited to welding thin or exotic materials where heat input limitation is critical. It also provides the extremely good spatter free welding..  

CO2 welding - Gas Metal Arc Welding using CO2 as the shielding gas.

Consumables - Items consumed during the welding process such as wire, gas, tips, shroud, wire feed components and even the welding torch and hoses etc.

Crater - The depression formed on the last section of a weld. A robot can easily fill the crater, but it adds to the cycle time.

Current - Another name for amperage. The amount of electricity flowing past a point in a conductor every second.

Deposition rate - The mass of metal deposited in a certain time. usually expressed in kg/hr.

Direct current (DC) - Flows in one direction and does not reverse its direction of flow as does alternating current

Duty cycle - The number of minutes out of a 10-minute time period an arc welding machine can be operated at maximum rated output. An example would be 60% duty cycle at 300 amps. This would mean that at 300 amps the welding machine can be used for 6 minutes and then must be allowed to cool with the fan motor running for 4 minutes. (Some manufacturers rate machines on a 5 minute cycle).

Fixed automation - Automated, electronically controlled welding system for simple, straight or circular welds.

Fixture - A device that holds components ready for welding.

Flexible automation - Automated, robotically controlled welding system for complex shapes and applications where welding paths require torch-angle manipulation.

Microprocessor - One or more integrated circuits that can be programmed with stored instructions to perform a variety of functions.

MIG (GMAW or Gas Metal Arc Welding) - An arc welding process which joins metals by heating them with an arc. The arc is between a continuously fed filler metal (consumable) electrode and the work piece. Externally supplied gas or gas mixtures provide shielding. Common MIG welding is also referred to as short circuit transfer. Metal is deposited only when the wire actually touches the work. No metal is transferred across the arc. Another method of MIG welding, spray transfer moves a stream of tiny molten droplets across the arc from the electrode to the weld puddle. Consumables: contact tips, shielding gas, welding wire.

Positioner - Also known as manipulator. A device that can place the joint in a favourable position for welding.

Pulsed MIG (MIG-P) - A modified spray transfer process that produces no or little spatter because the wire does not touch the weld puddle. Applications best suited for pulsed MIG are those currently using the short circuit transfer method for welding steel, 14 gauge (1.8 mm) and up. Consumables: contact tips, shielding gas, welding wire.

Pulsing - Sequencing and controlling the amount of current, the polarity, and the duration of the welding arc.

Rapid arc welding - A MIG transfer whereby the welding torch is positioned at a shallow angle and longer than usual stick out resulting in increased welding speeds.

Shielding gas - Protective gas used to prevent atmospheric contamination of the weld pool.

Spatter - The metal particles blown away from the welding arc. These particles do not become part of the completed weld.

Spot welding - Usually made on materials having some type of overlapping joint design. Can refer to resistance, MIG or TIG spot welding. Resistance spot welds are made from electrodes on both sides of the joint, while TIG and MIG spots are made from one side only.

Stick out - The distance from the welding tip to joint.

Strong back - A beam or frame that spans across the fixture discs of a positioner from which a fixture is mounted.

Synergic welding - Automatic selection of the welding parameters for a given wire/gas combination through computer control. Only one parameters needs to be set (usually the wire feed speed), whilst all others are adjusted automatically to provide optimum results.

TCP (Tool Centre Point) - The TCP is the reference point from which the robot is programmed. This is the end of the wire as it protrudes from the welding tip and is normally set to a distance of 10 mm to 12 mm.

Teach pendant - A hand held device from which a robot can be programmed.

Torch cleaning station - A device that automatically cleans the shroud of the welding torch in a robotic welding system.

TIG welding (GTAW or Gas Tungsten Arc) - Often called TIG welding (Tungsten Inert Gas), this welding process joins metals by heating them with a tungsten electrode which should not become part of the completed weld. Filler metal is sometimes used and argon inert gas or inert gas mixtures are used for shielding. Consumables: tungsten electrode, filler metal, shielding gas.

Twin wire welding - For MIG welding: a method whereby two welding wires are fed into the weld pool resulting in increased welding speeds. The system can either feature two separate power sources or a single power source.

Voltage - The pressure or force that pushes the electrons through a conductor. Voltage does not flow, but causes amperage or current to flow. Voltage is sometimes termed electromotive force (EMF) or difference in potential.

Weld metal - The electrode and base metal that was melted while welding was taking place. This forms the welding bead.

Weld transfer - Method by which metal is transferred from the wire to the molten puddle. There are several methods used in MIG; they include:dip transfer (or short circuit transfer*, spray arc transfer, globular transfer, buried arc transfer, and pulsed arc transfer.

Welding speed - The velocity expressed in in/min, mm/sec or m/min that the gun travels along a joint.

Wire feed speed - Expressed in in/min, mm/s or m/min, and refers to the speed and amount of filler metal fed into a weld. Generally speaking the higher the wire feed speed, the higher the amperage.

Return to the top >>>