Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the...
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Transcript of Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the...
![Page 1: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/1.jpg)
Welding Defects and Discontinuities
![Page 2: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/2.jpg)
What does weld defect mean?
• Any flaw that compromises the usefulness of a weldment (weld)
![Page 3: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/3.jpg)
What does weld discontinuity mean?
• An interruption of the typical structure of a material. A discontinuity is not necessarily a defect.
![Page 4: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/4.jpg)
Weld Joint Discontinuities• Inclusions
– Slag
– Wagontracks
– Tungsten
• Spatter
• Arc Craters
• Cracks– Longitudinal
– Transverse
– Crater
– Throat
– Toe
– Root
– Underbead and Heat-affected zone
– Hot
– Cold or delayed
• Misalignment (hi-lo)
• Undercut
• Underfill
• Concavity or Convexity
• Excessive reinforcement
• Improper reinforcement
• Insufficient Fill
• Overlap
• Burn-through
• Incomplete or Insufficient Penetration
• Incomplete Fusion
• Surface irregularity– Overlap
• Arc Strikes
• Base Metal Discontinuities
– Lamellar tearing
– Laminations and Delaminations
– Laps and Seams
• Porosity– Uniformly Scattered
– Cluster
– Linear
– Piping
• Hammer Marks • Heat-affected zone
microstructure alteration• Base Plate laminations• Size or dimensions
![Page 5: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/5.jpg)
Weld Joint Discontinuities• Inclusions
– Slag
– Wagontracks
– Tungsten
• Spatter
• Arc Craters
• Cracks– Longitudinal
– Transverse
– Crater
– Throat
– Toe
– Root
– Underbead and Heat-affected zone
– Hot
– Cold or delayed
• Misalignment (hi-lo)
• Undercut
• Underfill
• Concavity or Convexity
• Excessive reinforcement
• Improper reinforcement
• Insufficient Fill
• Overlap
• Burn-through
• Incomplete or Insufficient Penetration
• Incomplete Fusion
• Surface irregularity– Overlap
• Arc Strikes
• Base Metal Discontinuities
– Lamellar tearing
– Laminations and Delaminations
– Laps and Seams
• Porosity– Uniformly Scattered
– Cluster
– Linear
– Piping
• Hammer Marks • Heat-affected zone
microstructure alteration• Base Plate laminations• Size or dimensions
![Page 6: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/6.jpg)
Misalignment (hi-lo)
• Definition: Joint is out of alignment at the root• Cause: Carelessness
![Page 7: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/7.jpg)
Undercut• Definition: A groove cut at the toe of the weld
and left unfilled.
• Cause: High amperage, electrode angle, long arc length, or rust
![Page 8: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/8.jpg)
Insufficient Fill
• Definition: The weld surface is below the adjacent surfaces of the base metal
• Cause: Improper welding techniques
![Page 9: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/9.jpg)
Burn-through
• Definition: When a hole has been completely melted through the base metal.
• Cause: Excessive heat input.
![Page 10: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/10.jpg)
Incomplete or Insufficient Penetration
• Definition: When the weld metal does not extend to the required depth into the joint root
• Cause: Low amperage, low preheat, tight root opening, fast travel speed, short arc length.
![Page 11: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/11.jpg)
Arc Strike
• Definition: A localized coalescence outside the weld zone.
• Cause: Carelessness
![Page 12: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/12.jpg)
Slag Inclusion
• Definition: Slag entrapped within the weld
• Cause: Low amperage, improper technique, Trying to weld in an area that is too tight.
![Page 13: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/13.jpg)
Spatter
• Definition: Small particles of weld metal expelled from the welding operation which adhere to the base metal surface.
• Cause: Long arc length, severe electrode angles, high amperages.
![Page 14: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/14.jpg)
Cracks• When the metal cracks due to shrinkage,
temperate change, and stress on the weld
![Page 15: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/15.jpg)
Porosity
• Weld metal contamination in the form of a trapped gas being trapped in the molten metal
![Page 16: Welding Defects and Discontinuities. What does weld defect mean? Any flaw that compromises the usefulness of a weldment (weld)](https://reader033.fdocuments.in/reader033/viewer/2022061509/5697c0281a28abf838cd6d12/html5/thumbnails/16.jpg)
Hammer Marks
• When you chip the slag to hard and it dents the weld