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Root Defects. Internal Defects.Surface Defects.
عیوب ریشه عیوب میانی
عیوب سطحی
از لحاظ نوع ایجاد تمرکز تنش
با اهمیت متوسط با اهمیت کم بااهمیت باال
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
QUESTIONS ?
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