The document discusses weld defects, their causes, and remedies. It identifies eight main types of structural weld defects: crater cracks, longitudinal cracks, cross-sectional cracks, undercutting, slag inclusion, porosity, poor penetration, and incomplete fusion. Each defect is described along with its potential causes, such as improper welding technique, incorrect electrode or current usage, or poor joint preparation. The objective is to help identify different weld defects, understand what causes them, and take appropriate measures to remedy issues.

1. Weld Defects, Causes,
and Remedies

2. Objective:
At the end of the lesson, you are
expected to;
Identify the different weld
defects its causes and
remedies.

3. A weld should have a good
appearance. However, a defective
weld is one that will be strong
enough to do the job and may fail
after it is put into used. Weld
defects usually happen when the
correct preparation and/or welding
techniques are not used.
Weld Defects

4. General Classification of Weld Defects:
1. Structural Defects – include surface and
internal cracks and defects
Types of Structural Defects:
1.1 Crater Cracks – cracks
left at the depression at the
end of the bead.
Cause:
Improper termination of the
electrode at the end of the
weld

5. 1.2 Longitudinal Cracks – cracks run parallel to the
weld bead. They may be in the bead itself or in
the metal along the edge of the bead.
Causes:
a. Wrong electrode
b. Improper joint
design
c. Poor edge
preparation
d. Poor clamping of
the welded joint
General Classification of Weld Defects:

6. 1.3 Cross-sectional Crack – cracks across the weld
bead.
Causes:
a. Wrong electrode
b. Improper joint design
c. Poor edge preparation
d. Poor clamping of the
welded joint
General Classification of Weld Defects:

7. 1.4 Undercutting – depression at the toe of the
weld – the weld metal is below the level of the
base metal.
Causes:
a. Faulty electrode
manipulation
b. Current too high
c. Travel speed is too slow
General Classification of Weld Defects:

8. 1.5 Slag Inclusion – entrapment of nonmetallic
materials such as cellulose or limestone at the
weld and base metal.
Causes:
a. Poor edge preparation
b. Dirty filler metal and
Parent metal
c. Incorrect use of the
different welding
techniques
General Classification of Weld Defects:

9. 1.6 Porosity – small gas pockets or holes in the
welded metal
Causes:
a. Dirty filler metal and
parent metal
b. Too short arc length
c. Insufficient paddling
time
General Classification of Weld Defects:

10. 1.7 Poor Penetration – happens when the joint or
root weld penetration does not meet the weld
requirement for full strength
Causes:
a. Poor edge preparation
b. Travel speed is too fast
c. Low current setting
General Classification of Weld Defects:

11. General Classification of Weld Defects:
1.8 Incomplete Fusion – when the filler metal and
parent metal are not completely fused
Causes: a. Poor edge preparation
b. Travel speed is too fast
c. Low current setting

12. GOOD LUCK!!!