Root Defects. Internal Defects. Surface Defects. عیوب ریشه عیوب میانی عیوب سطحی.

Root Defects. Internal Defects.Surface Defects.

عیوب ریشه عیوب میانی

عیوب سطحی

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1- 4 5 - 7 8- 10

EQUIAXED LINEAR VOLUMETRIC PLANAR Rounded and Slag lines Linear from at Non linear Elongated porosity least one

directionGas pores Slag inclusions Cracks, lack of

fusion

INCOMPLETE ROOT PENETRATION.

LACK OF ROOT FUSION.

ROOT CONCAVITY.

BURN THROUGH.

EXCESS PENETRATION.

DEFINITION:Failure of weld metal to extend into the root of ajoint.CAUSES:Root faces too largeRoot gap too smallElectrode dia too largeIncorrect electrode angleArc length too longTravel speed too high forcurrent

عدم نفوذ پاس ریشه

DEFINITION:Lack of union at the root of the weld.

CAUSES:Amperage too low /

too highContaminated weld

preps

عدم ذوب ریشه

DEFINITION:A shallow groove that

mayoccur in the root of a

butt weld.

CAUSES:Root face too largeLow arc energyExcessive back purgeExcessive root

grinding

تقعر پاس ریشه

نفوذ بیش از حد پاس ریشه

DEFINITION:Excessive weld metalprotruding through the root of a fusion weld

madefrom one side only.CAUSES:Excessive amperageExcessive root gapSmall root faceIncorrect welding techniqueType of electrode

DEFINITION:A localised collapse of the molten pool due to excessive penetration,resulting in a hole in the weld run.CAUSES:Excessive currentExcessive root grindingIncorrect welding technique

LACK OF SIDE WALL FUSION.

LACK OF INTER RUN FUSION.

POROSITY.

SLAG INCLUSIONS.

DEFINITION:Lack of union in a

weld.

CAUSES:Contaminated weld

prepAmperage too low /

high

DEFINITION:A group of gas pores, formed by entrapped

gasduring the

solidificationof molten metal.Blowhole - a cavity generally over 1.5mm.Wormhole (piping) - elongated or tubular cavity.

DEFINITION:A fused, non-metallic residue produced from some processes.

CAUSES:Insufficient cleaningContaminationArc length too longWelding over irregularprofile

ARC STRIKES.SURFACE CRACKS.SPATTER.POROSITY.EXCESS WELD METAL.CRATER PIPE.UNDERCUT. INCOMPLETELY FILLED GROOVE.OVERLAP.POOR WELD PROFILE.

DEFINITION:Damage on the parent material resulting from

the accidental striking of an arc from the weld.

CAUSES:Electrode straying intoparent materialElectrode holder Poor contact of return / earth clamp

DEFINITION:A linear discontinuity produced by fracture. Cracks may be longitudinal,transverse,edge, centreline, fusionzone, under bead, weld metal or parent metal.Weld metal cracks.Heat affected zone

cracksParent material/HAZ

DEFINITION:Small droplets of

electrodematerial which have strayed away from the arc which may or may

nothave fused to the

parent plate.CAUSES:Excessive arc energyArc - blowDamp electrodes

DEFINITION:A gas pore is a cavitygenerally under 1.5mm

india. Porosity is a group

ofgas pores.CAUSES:Moisture on prep / fluxContaminationArc length too longDamaged electrode fluxLoss of gas shield

DEFINITION:Additional weld metal, ateither the root or the

face,which may or may not be acceptable. Excess weld metal can cause a poor toe blend.CAUSES:Slow travel speedIncorrect welding

technique

DEFINITION:A depression due to shrinkage at the end

of a weld run, where the source of heat was removed.CAUSES:Deoxidation reactionLiquid to solid volume changeRapid cooling rate

DEFINITION:An irregular groove atthe toe of a weld runin the parent material,or in previously deposited weld metal, due to welding.CAUSES:Excessive welding

currentHigh welding speedWrong electrode angleExcessive weaving

DEFINITION:A continuous or intermittent channel in

the surface of a weld

running along its length, due to insufficient weld metal.CAUSES:Incorrect welding techniqueTravel speed too high

The weld metals is in the under surface of base metals

DEFINITION:An imperfection at the

toe or root of a weld caused by metal flowing onto the surface of the parent

plate without fusing to it.CAUSES:ContaminationSlow travel speedHigh amperageWelding technique

DEFINITION:A non uniform/irregularappearance at either the weld face or root. Can include excessive

rootpenetration/cap heightand poor cap profile.CAUSES:Poor welding technique.Too slow/fast travel

speedArc blow

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