Question

Why hydrogen increases arc voltage in welding?

Answer 1

Increasing arc voltage lengthens the arc so that weld bead width, reinforcement and flux consumption are increased as is the risk of arc blow. When alloying the weld metal from the flux, arc length and hence arc voltage must be carefully controlled as at high arc voltages more flux is melted allowing more alloying elements to enter the weld metal thereby affecting weld metal composition.