Dear Readers.
This is continuation of Part-5. Welding is a highly
technical field requiring specialized acronyms and abbreviations. This article
will be a valuable resource for anyone looking to enhance their knowledge of
the Welding Works.
Lap Joint – A joint between two overlapping members in
parallel planes.
Laser – A device that provides a concentrated coherent
light beam. Laser is an acronym for Light Amplification by Stimulated Emission
of Radiation.
Laser Beam Cutting – A process that severs material with
the heat from a concentrated coherent beam impinging upon the workpiece.
Laser Beam Welding – A process that fuses material with
the heat from a concentrated coherent beam impinging upon the members to be
joined.
Layer – A stratum of weld metal or surfacing material.
The layer may consist of one or more weld beads laid side by side.
Leads – These are the lines from the machine to what you
are welding that carry the current.
Leg of Fillet Weld – The distance from the root of the
joint to the toe of the fillet weld.
Liquidus – The lowest temperature at which a metal or an
alloy is completely liquid.
Local preheating – Preheating a specific portion of a
structure.
Local stress relief heat treatment – Stress relief heat
treatment of a specific portion of a structure.
Longitudinal sequence – The order in which the
increments of a continuous weld are deposited with respect to its length.
Machine Welding – Equipment performs the weld while a
person watches to make sure it is working right. They will also visually
inspect the completed weld.
Macro Testing – A destructive testing method where the
sections of a weld are polished, etched and examined under a microscope for
defects.
Mandrel – A metal bar serving as a core around which
other metals are cast, forged, or extruded, forming a true, center hole.
Manifold – A multiple header for interconnection of gas
or fluid sources with distribution points.
Manual Welding – A welding process where the torch or
electrode holder is manipulated by hand.
Mash Seam Welding – A seam weld made in a lap joint in
which the thickness at the lap is reduced to approximately the thickness of one
of the lapped joints by applying pressure while the metal is in a plastic
state.
Mechanical Bond – The adherence of a thermal-spray
deposit to a roughened surface by particle interlocking.
Mechanized Welding – Welding with equipment where manual
adjustment of controls is required in response to variations in the welding
process. The torch or electrode holder is held by a mechanical device.
Melting Point – The temperature at which a metal begins
to liquefy.
Melting Rate – How much of the rod (electrode), wire, or
TIG rod is melted in a certain amount of time. Or the temperature range between
solidus and liquidus.
Melt-Through – Visible reinforcement produced on the
opposite side of a welded joint from one side.
Metal-Arc Cutting – The process of cutting metals by
melting with the heat of the metal arc. Arc metal cutting is a thermal cutting process that uses an arc between an electrode and the workpiece to melt and remove metal.
Metal-Arc Welding – An arc welding process in which a
metal electrode is held so that the heat of the arc fuses both the electrode
and the work to form a weld.
Metal Cored Arc Welding – A tubular electrode process
where the hollow configuration contains alloying materials.
Metal Cored Electrode – A composite tubular electrode
consisting of a metal sheath and a core of various powdered materials,
producing no more than slag islands on the face of the weld bead. External
shielding is required.
Metal electrode – A fillet or non-filler metal
electrode, used in arc welding or cutting consisting of a metal wire or rod
that has been manufactured by any method and that is either bare or covered
with a suitable covering or coating.
Metallizing – A method of overlay or metal bonding to
repair worn parts.
Metallic bond – The principal bond which holds metals
together and which is formed between base metals and filler metals in all
welding processes.
Method – An orderly arrangement or set form of procedure
to be used in the application of welding or allied processes.
Microprocessor – One or more integrated circuits that
can be programmed with stored instructions to perform a variety of functions.
MIG – It may be technically called GMAW, but in the shop
Mig welding uses a solid steel wire rolled up on a spool and fed through a
welding lead with a liner in it. Drivers push, pull or both to feed the wire
through the lead to the welding gun.
Mixing Chamber – It is part of a welding or cutting
torch in which the gases are mixed for combustion.
Molecular Weight – The sum of the atomic weights of all
the constituent atoms in the molecule of an element or compound.
Molten weld pool – The liquid state of a weld prior to
solidification as weld metal.
Monochromatic – The color of a surface that radiates
light, containing an extremely small range of wavelengths.
MQP – Manufacturing Quality Plan. It is a basic test
during manufacturing process.
MTC / MTR – Material Test Certificate / Material Test
Report.
Multi-Impulse Welding – The making of spot, projection,
and upset welds by more than one impulse of current. When alternating current
is used each impulse may consist of a fraction of a cycle or a number of
cycles.
Multipass Welds – When multiple welds are applied to one
project.
