Stubbing in gas metal arc welding is caused by excessive which parameter?

Stubbing in gas metal arc welding is caused by excessive which parameter?

• A. Wire feed speed
• B. Resistance
• C. Arc force
• D. Voltage

Answer: (A)

Stubbing happens when the filler wire is fed into the arc too quickly for the molten pool to accept it. In short-circuit GMAW, metal is transferred as the wire makes contact and the arc re-ignites. If the wire feed speed is excessive, the wire end pushes into the puddle faster than the pool can fuse it, causing frequent small shorts and interruptions in the arc. The result is a bead with stubs and rough transfer. Other parameters affect arc stability and heat, but they don’t directly cause stubbing the way pushing the wire too fast does, so reducing the wire feed speed to match the pool’s capacity stops the stubbing and yields a smoother, continuous bead.

Stubbing happens when the filler wire is fed into the arc too quickly for the molten pool to accept it. In short-circuit GMAW, metal is transferred as the wire makes contact and the arc re-ignites. If the wire feed speed is excessive, the wire end pushes into the puddle faster than the pool can fuse it, causing frequent small shorts and interruptions in the arc. The result is a bead with stubs and rough transfer. Other parameters affect arc stability and heat, but they don’t directly cause stubbing the way pushing the wire too fast does, so reducing the wire feed speed to match the pool’s capacity stops the stubbing and yields a smoother, continuous bead.