Core Parameters
Welding Current
This is the most critical parameter determining weld penetration. It must be selected based on the base metal material, thickness, joint configuration, and welding position. Excessive current can lead to undercut or burn-through, while insufficient current may result in incomplete penetration.
Arc Voltage
Directly determined by the arc length, this primarily affects the weld bead width. For autogenous welding (without filler wire), the arc length is typically maintained at 1–3 mm; when using filler wire, it is approximately 3–6 mm. Excessive voltage can cause arc instability (wandering) and compromise shielding effectiveness.
Welding Speed
This directly affects the heat input per unit length of the weld. Excessive speed can lead to incomplete penetration and porosity, while excessively slow speeds may cause overheating and deformation. High-speed welding requires corresponding adjustments to gas flow rates to prevent the shielding gas from being disrupted by airflow.
Filler Wire Feed Speed and Wire Diameter
The wire diameter must match the base metal thickness and joint gap. The feed speed is determined by a combination of wire diameter, welding current, and welding speed to ensure uniform filling of the weld pool.
