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MISCELLANEOUS INFORMATION DESTRUCTIVE

TESTING

DT – series of tests by destruction to determine the quality of a weld.

DEWARS

Specially constructed tank similar to a vacuum bottle for the storage of Iiquified gases.

DIN Abbreviating for Deutsche lnstitut für Normung.

DIRECT CURRENT

Flow of current (electrons) in only one direction, either to the workpiece or to the electrode.

DIRECT CURRENT ELECTRODE

NEGATIVE (DCEN)

Direct current flowing from electrode to the work.

DIRECT CURRENT ELECTRODE

POSITIVE (DCEP)

Direct current from work to the electrode.

DIRECT CURRENT REVERSE POLARITY (DCRP)

See Direct Current Electrode Positive.

DIRECT CURRENT STRAIGHT POLARITY (DCRP) See Direct Current Electrode Negative.

DNV

Abbreviation for Det Norske Veritas (Norwegian classification institute).

DUCTILITY

Property of material causing it to deform permanently, or to exhibit plasticity without breaking while under tension.

DUTY CYCLE Arc/time factor – the relationship between the time the arc is in operation and the total working time measured over a period of 10 minutes. Expressed in % of the time the welding machine can work at a certain amperage in this period. I.e. a 30% intermittence the arc can be in operation 3 min. of the period. During the remaining time the machine will be at rest while electrodes are changed, slag removed etc.

ELECTRIC STEEL

Steel produced in an electro-furnace.

ELONGATION Permanent elastic extension which metal undergoes during tensile testing. Amount of extension is usually indicated by percentages of original gauge length. Measurements is usually based on 5 x D or 10 x D, where «D» is the diameter of the test rod. EN The European Community for standardization has developed a nomenclature in welding, Euronorm E.N.

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