Radiography Photos

7/24/2019 Radiography Photos

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Oil & Gas, Petrochemicals, and Infrastructure Solutions with a Difference

Photos of Defects found in

Radiography


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Cold Lap

The weld filler metal does not properly fuse with the base metal or

the previous weld pass material (interpass cold lap). The arc does

not melt the base metal sufficiently and causes the slightly molten

puddle to flow into the base material without bonding.


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Porosity

The result of gas entrapment in the solidifying metal

ometimes! porosity is elongated and may appear to have a tail. This is

the result of gas attempting to escape while the metal is still in a li"uid

state and is called wormhole porosity. #ll porosity is a void in the

material and it will have a higher radiographic density than the

surrounding area.


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Cluster porosity

caused when fux coated electrodes are contaminated withmoisture. The moisture turns into a gas when heated andbecomes trapped in the weld during the welding process.Cluster porosity appear just like regular porosity in the

radiograph but the indications will be grouped close together.


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lag inclusions

nonmetallic solid material entrapped in weld metal or between weld and

base metal. In a radiograph, dark, jagged asymmetrical shapes within

the weld or along the weld joint areas are indicative o slag inclusions.


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$ncomplete penetration ($P) or lac% of penetration (L&P)

occurs when the weld metal ails to penetrate the joint. It is one o the mostobjectionable weld discontinuities. ack o penetration allows a naturalstress riser rom which a crack may propagate. The appearance on aradiograph is a dark area with well!de"ned, straight edges that ollows

the land or root ace down the center o the weldment.


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$ncomplete fusion

a condition where the weld "ller metal does not properly usewith the base metal. #ppearance on radiograph$ usuallyappears as a dark line or lines oriented in the direction o the

weld seam along the weld preparation or joining area.


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$nternal concavity or suc% bac%

a condition where the weld metal has contracted as it cools andhas been drawn up into the root o the weld. %n a radiograph itlooks similar to a lack o penetration but the line has irregularedges and it is oten &uite wide in the center o the weld image.


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$nternal or root undercut

an erosion o the base metal next to the root o the weld. In theradiographic image it appears as a dark irregular line o'set rom

the centerline o the weldment. (ndercutting is not as straightedged as %) because it does not ollow a ground edge.


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'ternal or crown undercut

an erosion o the base metal next to the crown o the weld. In theradiograph, it appears as a dark irregular line along the

outside edge o the weld area.


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&ffset or mismatch

terms associated with a condition where two pieces being weldedtogether are not properly aligned. The radiographic imageshows a noticeable di'erence in density between the twopieces. The di'erence in density is caused by the di'erence inmaterial thickness. The dark, straight line is caused by the

ailure o the weld metal to use with the land area.


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$nade"uate weld reinforcement

an area o a weld where the thickness o weld metal deposited is lessthan the thickness o the base material. It is very easy to determineby radiograph i the weld has inade&uate reinorcement, because theimage density in the area o suspected inade&uacy will be higher*darker+ than the image density o the surrounding base material.


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'cess weld reinforcement

an area o a weld that has weld metal added in excess o thatspeci"ed by engineering drawings and codes. The appearanceon a radiograph is a localied, lighter area in the weld. # visualinspection will easily determine i the weld reinorcement is in

excess o that speci"ed by the engineering re&uirements.


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Crac%s

can be detected in a radiograph only when they are propagating in adirection that produces a change in thickness that is parallel to the x!ray beam. Cracks will appear as jagged and oten very aint irregularlines. Cracks can sometimes appear as -tails- on inclusions or porosity.

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Radiography Photos