14-16. Troubleshooting − Incomplete Fusion

 

 

Incomplete Fusion − failure of weld metal to fuse completely with

 

 

base metal or a preceeding weld bead.

 

 

 

 

 

 

 

 

 

Possible Causes

 

Corrective Actions

 

 

 

Insufficient heat input.

 

Increase amperage. Select larger electrode and increase amperage.

 

 

 

Improper welding technique.

 

Place stringer bead in proper location(s) at joint during welding.

 

 

 

 

 

Adjust work angle or widen groove to access bottom during welding.

 

 

 

 

 

Momentarily hold arc on groove side walls when using weaving technique.

 

 

 

 

 

Keep arc on leading edge of weld puddle.

 

 

 

Workpiece dirty.

 

Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before

 

 

welding.

 

 

 

14-17. Troubleshooting − Lack Of Penetration

 

 

 

 

Lack Of Penetration − shallow fusion between weld metal and

 

 

 

 

base metal.

 

 

 

 

 

Lack of Penetration

Good Penetration

 

 

 

Possible Causes

 

Corrective Actions

 

 

 

Improper joint preparation.

 

Material too thick. Joint preparation and design must provide access to bottom of groove.

 

 

 

Improper weld technique.

 

Keep arc on leading edge of weld puddle.

 

 

 

Insufficient heat input.

 

Increase amperage. Select larger electrode and increase amperage.

 

 

 

 

 

 

 

 

 

Reduce travel speed.

 

 

 

 

 

14-18. Troubleshooting − Excessive Penetration

 

 

 

 

Excessive Penetration − weld metal melting through base metal

 

 

 

 

and hanging underneath weld.

 

 

 

 

 

Excessive Penetration

Good Penetration

 

 

 

Possible Causes

 

Corrective Actions

 

 

 

Excessive heat input.

 

Select lower amperage. Use smaller electrode.

 

 

 

 

 

 

 

 

 

Increase and/or maintain steady travel speed.

 

 

 

 

 

OM-4419 Page 61

Page 65
Image 65
Miller Electric Bobcat 250 manual Troubleshooting − Incomplete Fusion, Troubleshooting − Lack Of Penetration