How can I control the current intensity?

During welding, the current intensity needs to be adjusted comprehensively based on factors such as workpiece thickness, electrode diameter, and welding position. Fine-tuning should be made by observing the molten pool during trial welding to ensure good weld formation and sufficient fusion.

I. Core Control Principles
* **Adjusting Current According to Material Thickness:** The thicker the workpiece, the greater the current required to ensure sufficient penetration. For example, when welding a 2mm thin plate, the current can be set to 120–150A, while plates thicker than 3mm require 180A or more.

* **Matching Electrode Diameter:**
Fine electrodes (e.g., 2.5mm): 70–80A
Commonly used 3.2mm electrodes: 110–115A (suitable for beginners)
Coarse electrodes (4.0mm): 160–170A
The thicker the electrode, the greater the current required to avoid "electrode sticking" or uneven melting.

Considering Welding Position
Flat Welding: Higher current can be used
Vertical Welding, Overhead Welding: Current should be reduced by about 20% to prevent molten pool from sagging or metal dripping
II. Real-time Judgment and Fine-tuning Method (“Three-Sense Method”)

Adjust promptly through sensory feedback during welding:

Listen to the sound:
Suitable current → Steady “hissing” sound (like frying an egg)
Too low current → Intermittent “crackling” sound, easy for the weld to stick
Too high current → “crackling” popping sound, violent spatter
Observe the arc and spatter:
Moderate current → Stable arc, less spatter
Too high current → Dazzling arc light, sparks flying
Too low current → Weak arc light, frequent sticking
Check weld formation (observe after slag removal):
Good weld bead → Uniform fish-scale pattern, good fusion
Too low current → Weld protrusion, incomplete penetration
Too high current → Undercut, burn-through, or pitting

III. Key Points for Current Control in Special Processes

CO₂ Gas Shielded Welding: The current is mainly determined by the wire feed speed; the higher the current, the deeper the weld penetration. Voltage affects the weld width and needs to be matched with the current. Empirical formula: Voltage (V) ≈ Current (A) × 0.04 + 16 (±1–2V) For example, 150A current corresponds to approximately 22V voltage.

Argon Arc Welding: Initially select the current based on the material thickness and tungsten electrode/welding wire diameter. Observe the weld pool size during welding—reduce the current if the weld pool is too large, and increase it if the weld pool is too small.

Spot Welding: Too low a current will lead to incomplete penetration; too high a current will cause spatter, shrinkage cavities, and other problems. It needs to be controlled in conjunction with electrode pressure and welding time.