Dabbing Pulsed Welding Waveform for Cored Wire Arc Stability
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Solution Overview
Problem
Pulsed welding regimes in MIG welding often limit travel speed, produce excessive spatter, and result in suboptimal penetration, especially with cored wire electrodes, where excessive energy addition leads to arc flare and short circuits.
Innovation Solution
A welding system with processing circuitry generating a waveform comprising a peak phase followed by a dabbing phase with lower current than the background level, allowing a brief short circuit for molten material transfer without additional energy for clearing, thereby maintaining a stable arc and reducing electrode heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pulsed welding regimes are used with cored wire electrodes, then material transfer is improved, but excessive energy is added to the wire causing arc flare and short circuits
Solution Approach 1:
The patent applies periodic pulsed welding action with distinct phases (peak, dabbing, background) to control material transfer. The pulsed current regime allows the wire to be heated and transfer material in controlled intervals, preventing continuous overheating while maintaining effective material deposition. The periodic nature of the pulses enables cooling periods between heating cycles.
Solution Approach 2:
The patent changes current parameters dynamically through three distinct phases: peak current for material detachment, reduced dabbing current for controlled transfer without excessive heating, and background current for arc maintenance. This parameter modulation allows effective material transfer while controlling wire temperature and preventing arc flare.
2Productivity
If additional current is applied to clear short circuits, then material transfer continues, but excessive energy addition causes arc flare
Solution Approach 1:
The patent converts the harmful short circuit condition into a beneficial dabbing phase. Instead of viewing the short circuit as a problem requiring high current clearing, the invention utilizes the short circuit period for controlled material transfer at reduced current. The harmful effect of shorting is transformed into a useful material deposition mechanism that prevents arc flare.
Solution Approach 2:
The patent employs periodic pulsed action where short circuits occur in a controlled, periodic manner during the dabbing phase. This periodic shorting allows material transfer while the low current level prevents excessive heating and arc flare. The rhythmical nature of pulsed short circuits enables continuous productivity without harmful effects.
3Productivity
If arc length is maintained at minimum for spanning gaps and increasing travel speed, then welding efficiency improves, but wire shorts to weld puddle requiring additional current
Solution Approach 1:
The patent uses periodic pulsed current to manage short circuits that occur when minimum arc length is maintained. The pulsed regime allows short circuits to occur periodically during the dabbing phase at reduced current levels, enabling continuous material transfer without requiring complex high-current clearing sequences. This simplifies the overall control while maintaining high travel speeds.
4Reliability
If conventional pulsed welding is used, then material transfer is controlled, but excessive spatter is produced requiring cleanup
Solution Approach 1:
The patent applies specific parameter changes during the dabbing phase, reducing current below background levels to control material transfer. This parameter modulation creates a controlled short circuit condition that deposits material cleanly with minimal spatter. The precise control of current parameters during material transfer prevents the excessive spatter typical of conventional pulsed welding.
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
This approach enhances weld quality and flexibility by minimizing arc length, reducing spatter, and maintaining a stable arc, even with cored wire electrodes, while allowing faster travel speeds and reduced energy input.
Implementation Method 1
processing circuitry configured to provide a control waveform comprising a peak phase followed immediately by a dabbing phase followed by a background phase
Implementation Method 2
during the dabbing phase having a current level lower than the background current level a very brief short circuit is established once the molten material from a welding electrode is already detaching from the electrode and transferring to a weld puddle
Implementation Method 3
it may be desirable to maintain the arc length at a minimum... the electrode may be heated by excessive current added to the wire, particularly insomuch as the weld current tends to flow through the wire sheath
Data Source
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AI summary
A pulsed welding regime includes a peak phase (72) in which energy is added to an electrode and a weld puddle, and a molten ball begins to detach from the electrode, followed by a dabbing phase (74) in which current is significantly reduced to place the ball in the weld puddle with addition of little or no energy. The resulting short circuit clears and the system proceeds to a background phase (70). The current in the dabbing phase is lower than the current during the background phase. The process may be specifically adapted for particular welding wires, and may be particularly well suited for use with cored wires. The dabbing phase allows for lower energy to be transferred to the sheath of such wires, and resets the arc length after each pulse cycle.