| Cracks |
| No. |
Defects |
Remedies |
|
1. |
High rigidity of joint |
Use preheating
Relieve residual stresses.
Minimize shrinkage stresses, Using back step or block
welding sequences. |
|
2. |
Poor Joint fit up |
Adjust root opening all
alignment |
|
3. |
Higher carbon content of weld metal and / or harden able base material/ |
Use proper
electrode
Use buttering layers wherever necessary |
|
4. |
Too Small a weld bead |
Decrease
travel speed to increase cross section of bead. |
|
5. |
High Sulphur content in base or |
Use
filler with high level of weld metal sulphur fixing element like Mn. |
|
6. |
Hot cracking |
Reduce the heat input. |
|
7. |
Cracking at the crater |
Filling
up the crator before withdrawing the electrode
Use taper power control device.
Use back step welding technique |
|
8. |
Higher harden
ability |
Preheat the
job.
Post weld heat treatment without cooling to room temperature. |
|
9. |
Hydrogen induced
cracking /Delayed cracking |
Use low Hydrogen
welding electrode
Use suitable preheat and post Weld heat treatment |
|
10. |
Presence of brittle phases in the Micro structure of the
base Material |
Soften the material before welding. |
|
11. |
Low ductility of the base material |
Use preheat.
Anneal the base metal
Use ductile weld metal. |
|
12. |
High residual stresses |
Redesign the weld metal and reduce restraints
Change welding sequence
Use intermediate stress-relief Heat treatment. |
|
13. |
Excessive dilution |
Change welding current.
Use buttering technique wherever possible. |
|
14. |
Under Cut |
Reduce Current
Use proper diameter of Electrode
Reduce weaving |
|
15. |
Spatter |
Reduce Current |