What are Welding Defects? – Types, Causes, and Remedies

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The irregularities formed in the given weld metal due to wrong welding process or incorrect welding patterns, etc. are known as welding defects.

The following table elaborates the different types of welding defects, their causes, and how to prevent these defects −

The irregularities formed in the given weld metal due to wrong welding process or incorrect welding patterns, etc. are known as welding defects.

The following table elaborates the different types of welding defects, their causes, and how to prevent these defects −

Welding DefectCauses of Welding DefectRemedies
Blow hole
  • Too fast cooling rate.

  • Wet, unclear or damaged electrode.

  • Too thick base metal.

  • Long or short arc length.

  • Rusted wire or flux.

  • Over welding speed.

  • Base metal covered with oil rust etc.

  • Proper maintenance

  • Clean properly before welding.

  • Proceed proper pre-heating.

  • Maintain proper arc length.

  • Reduce travelling speed.

  • Store wire and flux properly.

Slag Inclusion
  • Welding current is too low.

  • Improper groove shape.

  • Incomplete slag removal from the previous bead

  • Slow travelling speed.

  • Too large weaving width.

  • Use higher welding current.

  • Modify groove angle and root gap.

  • Remove the slag from previous bead completely.

  • Use higher travelling speed.

  • Decrease weaving width.

Cracks
  • Electrode is not of good quality or may be damped.

  • Base metal contains over carbon and manganese content.

  • Base metal having higher Sulphur content.

  • Welding is done without pre or post heating.

  • Too large welding current.

  • Thickness of base metal is much more.

  • Too strong restraint for groove.

  • Use proper electrode.

  • Use low hydrogen type electrode with higher basicity.

  • Avoid such metals.

  • Preheat base metal

  • Reduce welding current.

  • Modify the groove design.

Undercut
  • Too high welding current.

  • Improper manipulation.

  • Unclean base metal surface.

  • Excessive arc length.

  • Too high travel speed.

  • Base metal is overheated.

  • Reduce welding current.

  • Clean metal surface properly.

  • Reduce arc length.

  • Reduce travel speed.

  • Use small sized electrode.

Incomplete Penetration
  • Improper electrode.

  • Travel speed is too fast or too slow.

  • Arc voltage is too high.

  • Arc length is too high.

  • Improper welding skill.

  • Select the electrode with better penetration.

  • Adjust travel speed properly.

  • Increase the groove angle and root gap.

  • Reduce arc voltage.

  • Reduce arc length.

  • Practice more to improve welding skills.

Distortion
  • Excessive weld size.

  • Improper set-up and fixture.

  • Overheating of base plate.

  • Excessive layers.

  • Worn out tip.

  • Wire feeder does work smoothly.

  • Feed roller not fasten properly.

  • Make welds of specified size.

  • Clamp the parts securely.

  • Use thicker base plate.

  • Replace the worn out electrode.

  • Grease wire feeder.

  • Adjust feed roller properly.

Overlap
  • Too low welding current.

  • Too slow travel speed.

  • Properly use welding current.

  • Use proper travel speed.

Pit
  • Uncleaned electrode.

  • Weld metal contains high carbon or manganese.

  • Damp electrode.

  • Base metal cooling rate is too high.

  • Use good low hydrogen type electrode.

  • Use high basicity electrode.

  • Use dried electrode.

  • Reduce travel speed.

  • Use proper pre and post heating.

Bad Appearance
  • Bad electrode.

  • Worn out tip.

  • Overheating of base metal.

  • Lack of fusion in the weld bead.

  • Select proper electrode

  • Use proper travel speed.

  • Replace the worn out tip electrode with new one.

  • Reduce welding current.

  • Improve welding skill.

raja
Updated on 04-May-2022 14:41:24

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