YACAT MARK RAINIER DS.
ME5-1A
Common Welding Faults, Their Causes, Inspection Methods, and Corrective
Actions
1. Porosity (Gas Pockets in Weld)
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Causes:
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Contaminants (oil, rust, moisture) on base metal
o
Improper gas shielding (wind, leaks, incorrect flow)
o
High welding speed causing rapid solidification
o
Incorrect electrode or filler material
Inspection & Checking:
o
Visual inspection (small holes on the weld surface)
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Radiographic or ultrasonic testing
Corrective Actions:
o
Clean base metal before welding
o
Ensure proper shielding gas flow and equipment condition
o
Use the correct electrode and maintain a steady arc
2. Cracks (Long, Thin Fractures in Weld)
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Causes:
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Rapid cooling or excessive welding stress
o
High carbon content in base metal
o
Poor joint design (excessive restraint)
o
Insufficient preheating or post-weld heat treatment
Inspection & Checking:
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Visual inspection for surface cracks
o
Magnetic particle or dye penetrant testing for finer cracks
o
Ultrasonic testing for internal cracks
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Corrective Actions:
o
Preheat thicker materials before welding
o
Reduce cooling rate with controlled welding parameters
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Modify joint design to reduce stress
o
Use proper filler material compatible with base metal
3. Lack of Fusion (Incomplete Bonding Between Weld and Base Metal)
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Causes:
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Low heat input
o
Improper electrode angle
o
Contaminants on the base metal
o
Excessive welding speed
Inspection & Checking:
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Visual inspection for uneven or unbonded areas
o
Ultrasonic or radiographic testing
Corrective Actions:
o
Increase heat input by adjusting voltage/amperage
o
Clean base metal thoroughly
o
Use correct electrode angle and slower travel speed
4. Undercut (Groove Along Weld Toe)
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Causes:
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Excessive welding current
o
Poor electrode angle
o
Fast travel speed
Inspection & Checking:
o
Visual inspection (grooves at weld edges)
o
Measuring tools for depth evaluation
Corrective Actions:
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Reduce welding current
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Adjust electrode angle to improve fusion
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Reduce travel speed for better metal deposition
5. Slag Inclusions (Non-Metallic Particles in Weld)
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Causes:
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Incomplete slag removal between passes
o
Incorrect electrode handling
o
Poor welding technique
Inspection & Checking:
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Visual inspection (visible slag on surface)
o
Radiographic testing for internal slag
Corrective Actions:
o
Thoroughly clean slag between passes
o
Use correct electrode and welding angle
o
Improve bead placement and technique
6. Incomplete Penetration (Weld Metal Not Extending Through Joint Thickness)
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Causes:
o
Low heat input
o
Incorrect joint design
o
Incorrect electrode size or positioning
Inspection & Checking:
o
Visual inspection for weak joints
o
Ultrasonic or radiographic testing
Corrective Actions:
o
Increase heat input
o
Use correct groove preparation
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Ensure proper electrode size and placement