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Welder’s Handbook
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Induced Current or Induction – The phenomena of causing an electrical current to flow through a conductor when that conductor is subjected to a varying magnetic field. Inductance – (as applies to short circuiting arc welding) A feature in welding power sources designed for short circuiting arc welding to retard the rate of current rise each time the electrode touches the weld puddle. Inert Gas – A gas, such as helium or argon, which does not chemically combine with other elements. Such a gas serves as an effective shield of the welding arc and protects the molten weld metal against contamination from the atmosphere until it freezes.
Lack of Fusion – A nonstandard term for incomplete fusion.
Lack of Penetration – A nonstandard term for incomplete joint penetration.
Lap Joint – A joint between two overlapping members in parallel planes.
Level Wound – Spooled or coiled filler metal that has been wound in distinct layers such that adjacent turns touch.
Linear Discontinuity – A discontinuity with a length that is substantially greater than its width.
Linear Indication – A test result in which a discontinuity in the material being tested is displayed as a linear or aligned array. Local Preheating – A specific portion of a structure Longitudinal Bend Test – A test in which a specimen is bent to a specified bend radius
Ingot – Casting of steel (weighing up to 200 tons) formed at mill from melt of ore, scrap limestone, coke, etc.
Insulator – A material which has a tight electron bond, that is, relatively few electrons which will move when voltage (electrical pressure) is applied. Wood, glass, ceramics and most plastics are good insulators. Inter-pass Temperature – When making multiple-pass welds, the lowest temperature of the deposited weld metal at the time the next pass is started. Inverter Power Source – A high performance plasma power source design which takes advantage of advanced power semiconductor circuitry to reduce the size and weight of the transformer and hence the overall size of the power source.
Longitudinal Crack – A crack with its major axis orientation approximately parallel to the weld axis
Low Alloy Steels – Steels containing small amounts of alloying elements (usually 1½% to 5% total alloy content) which drastically improves their properties. Low Carbon Electrodes – A non-filler metal electrode used in arc welding and cutting, consisting of a carbon or graphite rod, which may be coated with copper or other materials.
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Low Hydrogen Electrodes – Stick electrodes that have coating ingredients that are very low in hydrogen content.
Joint Geometry / Design – The shape and dimensions of a joint in cross section prior to welding.
The low hydrogen level is achieved primarily by keeping the moisture content of the coating to a bare minimum.
Joint Penetration – The distance the weld metal extends from the weld face into a joint, exclusive of weld reinforcement. Joint Root – That portion of a joint to be welded where the members approach closes to each other. In cross section, the joint root may be either a point, a line, or an area. Joint Type – A weld joint classification based on five basic joint configurations such as a butt joint, corner joint, edge joint, lap joint, and T-joint. K Kerf – Opening through the plate where material is removed during the any kind of cutting operation. Killed Steel – Steel which has been sufficiently deoxidized during the melting cycle to prevent gases from evolving during the solidification period.
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Macroetch Test – A test in which a specimen is prepared with a fine finish, etched, and examined under low magnification.
Malleableizing – Annealing operation used in connection with the change of white cast iron to a malleable cast iron.
Manual Arc Welding – Welding with a coated electrode where the operator’s hand controls travel speed and the rate the electrode is fed into the arc. Martensite – A structure resulting from transformation of austenite at temperature considerably below the usual range, achieved by rapid cooling. It is made up of ultra-hard, needlelike crystals that are a supersaturated solid solution of carbon in iron.
Kilowatt – 1,000 watts
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