Arc Welding Current Waveform for Spatter and Short-Circuit Control
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Solution Overview
Problem
In arc welding using a shield gas with carbon dioxide as the main component, increasing the welding current at the initial stage of the arc period leads to significant vibration of the molten pool due to arc force, causing micro-short circuits and increased spatter.
Innovation Solution
An arc welding control method that alternately repeats short-circuit and arc periods, with specific current control strategies including increasing the welding current to a first value, reducing it to a second value, then increasing it again to a third value higher than the first, followed by a rapid reduction within 0.5 ms to suppress molten pool vibration and spatter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the welding current is increased at the initial stage of the arc period, then the occurrence of short circuit after the start of the arc period is suppressed, but the molten pool greatly vibrates due to arc force causing micro-short circuit and increasing spatter
Solution Approach 1:
The patent applies periodic action by implementing a multi-stage current control pattern within each arc period. The welding current is increased to a first current value, then reduced to a second current value, then increased to a third current value, and finally reduced again. This periodic modulation of current prevents continuous high current exposure that causes excessive molten pool vibration, while still achieving short circuit suppression at appropriate moments in the cycle.
Solution Approach 2:
The patent applies dynamics by making the welding current adjustable and time-dependent rather than constant. The current control system dynamically changes the welding current through multiple stages (first, second, and third current values) with different gradients and durations, allowing the system to adapt to different phases of the arc period and minimize spatter while maintaining welding quality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively reduces spatter generated during arc welding by suppressing molten pool vibration and micro-short circuits, while maintaining stable arc conditions.
Implementation Method 1
a molten pool greatly vibrates due to an arc force acting on a droplet during globular transfer
Data Source
AI summary
An arc welding control method is for performing control in an arc period. The control includes: (i) increasing a welding current to a first current value at a first gradient and maintaining the welding current at the first current value for a first period; (ii) reducing the welding current from the first current value to a second current value at a second gradient and maintaining the welding current at the second current value for a second period; (iii) increasing the welding current from the second current value to a third current value at a third gradient; and (iv) starting to reduce the welding current from the third current value within a third period, which is shorter than the first period, after the welding current reaches the third current value.