7-11. Troubleshooting – Lack Of Penetration

 

Lack Of Penetration – shallow

 

fusion between weld metal and

 

base metal.

Lack of Penetration

Good Penetration

 

S-0638

Possible Causes

Corrective Actions

Improper joint preparation.

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

 

maintaining proper welding wire extension and arc characteristics.

Improper weld technique.

Maintain normal gun angle of 0 to 15 degrees to achieve maximum penetration.

Keep arc on leading edge of weld puddle.

Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle.

Insufficient heat input.

Select higher wire feed speed and/or select higher voltage range.

Reduce travel speed.

7-12. Troubleshooting – Incomplete Fusion

Incomplete Fusion – failure of weld metal to fuse completely with base metal or a preceeding weld bead.

 

S-0637

 

 

Possible Causes

Corrective Actions

 

 

Workpiece dirty.

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

 

welding.

Insufficient heat input.

Select higher voltage range and/or adjust wire feed speed.

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.

Use correct gun angle of 0 to 15 degrees.

7-13. Troubleshooting – Burn-Through

Burn-Through – weld metal melting completely through base metal resulting in holes where no metal remains.

S-0640

Possible Causes

Corrective Actions

Excessive heat input.

Select lower voltage range and reduce wire feed speed.

Increase and/or maintain steady travel speed.

OM-1318 Page 30

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Image 34
Miller Electric 172 M-10 Gun manual Troubleshooting Lack Of Penetration, Troubleshooting Incomplete Fusion