I. Before Welding: Perform "Three Checks and Three Fixes" to Lay a Solid Foundation
1. Check Pipe End Quality and Fix Beveling Standards: The pipe beveling angle should be controlled between 30° and 45°, with a single-sided angle deviation ≤ 1.5°, and the assembly gap should be maintained at 2~4mm. If the beveling is asymmetrical (e.g., one side has a smaller angle), the dwell time of the welding torch on both sides needs to be adjusted through the control system. For every 1° difference, the dwell time on the smaller angle side should be reduced by 10ms to avoid poor fusion or excessive weld bead.
2. Check Equipment Status and Fix Stable Operation: Check that the bending radius of the welding torch cable is ≥ 150mm, and that the wire feeding hose is not kinked; confirm reliable grounding, no gas leaks, and argon purity ≥ 99.99%. Before starting the machine, perform a system self-check to ensure that the servo motor and sensors respond normally.
3. Check process parameters and determine matching scheme. Preset the current, voltage, and travel speed according to the material (stainless steel/carbon steel), wall thickness, and welding position (flat/vertical/overhead welding). For example:
Thin-walled tube (≤3mm): Current 80~120A, Voltage 12~16V
Medium-thick walled tube (6~10mm): Current 150~220A, Voltage 18~24V
Overhead welding position: Appropriately reduce travel speed, increase argon flow rate by 1~2L/min to prevent molten iron from dripping.
II. During welding: Master "three stabilities and one adjustment" for dynamic optimization.
1. Stabilize welding torch centering. After starting, closely observe whether the welding torch is aligned with the weld center. If there is a deviation, it can be finely adjusted via remote control: press the right button to deviate to the left, and the left button to deviate to the right (the directions are reversed when running in reverse) to ensure the weld bead is centered.
2. Stabilize the molten pool shape. Observe the size and fluidity of the molten pool. If the pool is too large, it indicates that the current is too high or the speed is too slow, which can easily lead to burn-through; if it is too small, the penetration depth is insufficient. The ideal state is a "teardrop" shaped molten pool with a clear tip penetrating the root of the bevel.
3. Stabilize the oscillation rhythm. For wide bevels, use a Z-shaped or sawtooth oscillation, combined with a reasonable oscillation frequency and dwell time. Current, voltage, oscillation frequency, and travel speed together determine the "fish scale" pattern formation effect-stable and uniform speed is key.
4. Adjust dynamic parameters. If the molten pool is found to be biased to one side, the arc voltage can be finely adjusted (increased by 0.5~1V on the biased side) to "pull back" the molten pool; slight weld offset (≤1mm) can be corrected online by inputting the "offset compensation value" on the operation panel.
III. Post-weld: Implement "three inspections and one protection" for closed-loop management.
Appearance inspection: The weld surface is flat and smooth, without cracks, porosity, slag inclusions, and the rolled edges are uniform. Dimensional Acceptance: Axis misalignment is normal, edge misalignment is ≤10% of wall thickness, and length meets tolerances.
Sealing Acceptance: Pressure test is performed; no leakage is observed during pressure holding.
Equipment Maintenance: Clean welding slag daily, check track straightness and welding torch positioning accuracy weekly, and perform a full calibration monthly to extend equipment lifespan.
