Influence of welding current, voltage and welding speed on weld seam

The main energy parameters that determine the weld size are welding current, voltage and welding speed.

1.Welding current

When the welding current increases (other conditions remain unchanged), the weld penetration and residual height increase, but the weld width changes little (or slightly)

（1）With the increase of current, the arc force and heat input increase, the position of heat source moves down, the penetration depth increases, and the penetration depth is almost proportional to the welding current.  

（2）With the increase of current, the melting amount of welding wire increases proportionally. Because the melting width is almost unchanged, the reinforcement increases.

（3）With the increase of current, the diameter of arc column and the depth of arc increase, and the movement of arc spot is limited, so the width of weld remains unchanged.

2.Arc voltage

As the arc voltage increases, the arc power increases, the arc length lengthens and the distribution radius increases, so the penetration decreases, the width increases and the reinforcement decreases because the width increases and the melting amount of welding wire decreases slightly.

3.Welding speed

When the welding speed increases, the energy decreases, the penetration and the width decrease, because the deposition of the wire metal in the unit length weld is inversely proportional to the welding speed, and the weld width is inversely proportional to the opening of the welding speed.

The welding current has an impact on the penetration. If the current is small, the arc is unstable, and the defects such as slag inclusion and incomplete penetration are easy to appear. If the current is too large, the defects such as undercut and burn through are easy to appear, causing spatter. It can be selected according to the diameter of the electrode, and then it can be adjusted according to the position of the weld, the joint form, the welding level and the thickness of the weldment.

Arc voltage mainly affects the width of weld, and arc length determines arc voltage, arc length, arc voltage is high, arc short, arc voltage is low.

When welding, the arc should not be too long, otherwise it will lead to unstable combustion, increase metal spatter, and produce pores. Short arc should be used when welding, and the arc length should not exceed the diameter of electrode.

The welding speed is related to the welding productivity. On the premise of ensuring the quality, if you want to obtain the maximum welding speed, you can choose a larger electrode diameter and welding current, and adjust it appropriately according to the situation to ensure the consistency of weld height and width.