1. Root Defects. Internal Defects. Surface Defects.
WELD DEFECTS.
عیوب جوش
Root Defects.
Internal Defects.
Surface Defects.
عیوب ریشه
عیوب میانی
عیوب سطحی
وحید وفاییان

2. تقسیم بندی عیوب از لحاظ نوع ایجاد تمرکز تنش
با اهمیت کم با اهمیت متوسط بااهمیت بالا
EQUIAXED LINEAR VOLUMETRIC PLANAR
Rounded and Slag lines Linear from at
Non linear Elongated porosity least one direction
Gas pores Slag inclusions Cracks, lack of fusion

3. عیوب ریشه جوش INCOMPLETE ROOT PENETRATION. LACK OF ROOT FUSION.
ROOT CONCAVITY.
BURN THROUGH.
EXCESS PENETRATION.

4. INCOMPLETE ROOT PENETRATION
DEFINITION:
Failure of weld metal to
extend into the root of a
joint.
CAUSES:
Root faces too large
Root gap too small
Electrode dia too large
Incorrect electrode angle
Arc length too long
Travel speed too high for
current
عدم نفوذ پاس ریشه

5. INCOMPLETE ROOT FUSION
DEFINITION:
Lack of union at the
root of the weld.
CAUSES:
Amperage too low / too
high
Contaminated weld preps
عدم ذوب ریشه

6. ROOT CONCAVITY تقعر پاس ریشه DEFINITION: A shallow groove that may
occur in the root of a butt
weld.
CAUSES:
Root face too large
Low arc energy
Excessive back purge
Excessive root grinding
تقعر پاس ریشه

7. EXCESS PENETRATION نفوذ بیش از حد پاس ریشه DEFINITION:
Excessive weld metal
protruding through the
root of a fusion weld made
from one side only.
CAUSES:
Excessive amperage
Excessive root gap
Small root face
Incorrect welding
technique
Type of electrode
نفوذ بیش از حد پاس ریشه

8. BURN THROUGH DEFINITION: A localised collapse of
the molten pool due to
excessive penetration,
resulting in a hole in
the weld run.
CAUSES:
Excessive current
Excessive root grinding
Incorrect welding
technique

9. ROOT HAZ CRACK

10. INTERNAL DEFECTS LACK OF SIDE WALL FUSION. LACK OF INTER RUN FUSION.
POROSITY.
SLAG INCLUSIONS.

11. LACK OF SIDEWALL FUSION
DEFINITION:
Lack of union in a weld.
CAUSES:
Contaminated weld prep
Amperage too low / high

12. LACK OF INTERUN FUSION

13. POROSITY DEFINITION: A group of gas pores, formed by entrapped gas
during the solidification
of molten metal.
Blowhole - a cavity
generally over 1.5mm.
Wormhole (piping) -
elongated or tubular
cavity.

14. GAS PORE

15. SLAG INCLUSION DEFINITION: A fused, non-metallic residue produced from
some processes.
CAUSES:
Insufficient cleaning
Contamination
Arc length too long
Welding over irregular
profile

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

17. ARC STRIKE (STRAY FLASH)
DEFINITION:
Damage on the parent
material resulting from the
accidental striking of an
arc from the weld.
CAUSES:
Electrode straying into
parent material
Electrode holder
Poor contact of return /
earth clamp

18. SURFACE CRACKS DEFINITION: A linear discontinuity
produced by fracture.
Cracks may be
longitudinal,transverse,
edge, centreline, fusion
zone, under bead, weld
metal or parent metal.
Weld metal cracks.
Heat affected zone cracks
Parent material/HAZ

19. SPATTER DEFINITION: Small droplets of electrode material which have
strayed away from the
arc which may or may not
have fused to the parent
plate.
CAUSES:
Excessive arc energy
Arc - blow
Damp electrodes

20. GAS PORES/POROSITY DEFINITION: A gas pore is a cavity
generally under 1.5mm in
dia. Porosity is a group of
gas pores.
CAUSES:
Moisture on prep / flux
Contamination
Arc length too long
Damaged electrode flux
Loss of gas shield

21. SURFACE BREAKING POROSITY.

22. EXCESS WELD METAL DEFINITION: Additional weld metal, at
either the root or the face,
which may or may not
be acceptable. Excess
weld metal can cause a
poor toe blend.
CAUSES:
Slow travel speed
Incorrect welding technique

23. CRATER PIPE DEFINITION: A depression due to shrinkage at the end of
a weld run, where the
source of heat was
removed.
CAUSES:
Deoxidation reaction
Liquid to solid volume
change
Rapid cooling rate

24. UNDERCUT DEFINITION: An irregular groove at the toe of a weld run
in the parent material,
or in previously
deposited weld metal,
due to welding.
CAUSES:
Excessive welding current
High welding speed
Wrong electrode angle
Excessive weaving

25. INCOMPELTELY FILLED GROOVE
DEFINITION:
A continuous or
intermittent channel in the
surface of a weld running
along its length, due to
insufficient weld metal.
CAUSES:
Incorrect welding
technique
Travel speed too high

26. INCOMPLETELY FILLED GROOVE
The weld metals is in
the under surface of
base metals

27. OVERLAP 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:
Contamination
Slow travel speed
High amperage
Welding technique

28. OVER LAP AT TOE OF FILLET WELD

29. POOR WELD PROFILE / BULBOUS CONTOUR
DEFINITION:
A non uniform/irregular
appearance at either
the weld face or root.
Can include excessive root
penetration/cap height
and poor cap profile.
CAUSES:
Poor welding technique.
Too slow/fast travel speed
Arc blow

30. WELD DEFECTS.
QUESTIONS ?