defects versus dicontinuities in teh welded joints

1. Discontinuity
• An interruption of the typical structure of a
material, such as a lack of homogeneity in its
mechanical, metallurgical, or physical
characteristics. A discontinuity is not
necessarily a defect.

2. Weld Joint Discontinuities
• Misalignment (hi-lo)
• Undercut
• Underfill
• Concavity or Convexity
• Excessive reinforcement
• Improper reinforcement
• Overlap
• Burn-through
• Incomplete or Insufficient
Penetration
• Incomplete Fusion
• Surface irregularity
– Overlap
• Arc Strikes
• Inclusions
– Slag
– Wagontracks
– Tungsten
• Spatter
• Arc Craters
• Cracks
– Longitudinal
– Transverse
– Crater
– Throat
– Toe
– Root
– Underbead and
Heat-affected zone
– Hot
– Cold or delayed
• Base Metal
Discontinuities
– Lamellar tearing
– Laminations and
Delaminations
– Laps and Seams
• Porosity
– Uniformly Scattered
– Cluster
– Linear
– Piping
• Heat-affected zone
microstructure alteration
• Base Plate laminations
• Size or dimensions

3. Defect
• A flaw or flaws that by nature or accumulated
effect render a part or product unable to meet
minimum applicable acceptance standards or
specifications. The term designates
rejectability.

4. The following figures give a rough survey about the
classification of welding defects to DIN 8524. This standard does
not classify existing welding defects according to their origin but
only to their appearance.
4
Welding defect

5. 5
Welding defect

6. 6
Welding defect

7. 7
Welding defect

8. 8
Welding defect

9. 9
Welding defect

10. 10
Welding defect

11. 11
Welding defect

12. 12
Welding defect

13. 13
Welding defect