What is a consequence of excessive arc voltage in FCAW?

What is a consequence of excessive arc voltage in FCAW?

• A. Heavy spatter and possible porosity
• B. Improved bead quality
• C. Decreased heat input
• D. Decreased penetration

Answer: (A)

Excessive arc voltage lengthens the arc and raises the heat input. In FCAW, a longer arc is less focused, causing more molten metal to be expelled as spatter and making the weld easier for gas shielding to be disturbed. The shielding gas or flux core that protects the weld pool can be blown away or diluted with a longer arc, increasing the chance of gas being trapped in the weld as porosity. So the combination of heavy spatter and porosity is a direct result of too-high voltage, while bead quality drops as a consequence of these defects.

Excessive arc voltage lengthens the arc and raises the heat input. In FCAW, a longer arc is less focused, causing more molten metal to be expelled as spatter and making the weld easier for gas shielding to be disturbed. The shielding gas or flux core that protects the weld pool can be blown away or diluted with a longer arc, increasing the chance of gas being trapped in the weld as porosity. So the combination of heavy spatter and porosity is a direct result of too-high voltage, while bead quality drops as a consequence of these defects.