Pulsed Welding Waveform With Dabbing Phase for Spatter Control
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Solution Overview
Problem
Pulsed welding regimes face limitations such as reduced travel speed, excessive spatter, suboptimal penetration, and energy addition issues, particularly with cored wire electrodes, leading to arc flare and unwanted weld effects.
Innovation Solution
A welding system with processing circuitry generating a control waveform comprising a peak phase followed by a dabbing phase and a background phase, providing power conversion for controlled pulsed welding, which regulates energy transfer to minimize arc length and prevent excessive heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pulsed welding processes are used to regulate droplet deposition and control shorting, then weld quality and penetration are improved, but travel speed is limited and spatter increases
Solution Approach 1:
The patent applies periodic pulsed welding action with distinct phases (peak phase for droplet detachment, dabbing phase for controlled transfer, background phase for pool maintenance) to achieve both high weld quality and improved travel speed. The cyclic nature of the pulsed waveform allows precise control over each welding cycle, enabling faster progression while maintaining quality standards.
2Manufacturing precision
If pulsed welding processes operate in spray mode to improve material transfer, then penetration is enhanced, but the process runs excessively hot causing spatter and unwanted weld effects
Solution Approach 1:
The welding process is segmented into distinct phases: peak phase for high-current penetration, dabbing phase for controlled metal transfer, and background phase for pool maintenance. This segmentation allows the process to achieve deep penetration during the peak phase while the subsequent dabbing and background phases control temperature and prevent excessive spatter by reducing current when penetration is achieved.
Solution Approach 2:
The periodic pulsed waveform alternates between high-current peak phases for penetration and lower-current dabbing/background phases for temperature control. This periodic action enables the process to achieve deep penetration intermittently while maintaining overall temperature control, preventing the continuous overheating associated with spray mode welding.
3Length of moving object
If pulsed welding processes implement cyclic short circuits to maintain arc length, then gap spanning capability is improved, but excessive energy is added to the weld causing arc flare and spatter
Solution Approach 1:
The periodic pulsed waveform implements controlled short circuits during the dabbing phase to maintain arc length and enable gap spanning. By timing these short circuits to occur during the lower-current background phase rather than during peak current, the process achieves arc length control and gap bridging while minimizing excessive energy addition that would cause arc flare and spatter.
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 solution improves weld quality and flexibility by reducing energy addition to the weld and electrode, maintaining a stable arc, and minimizing spatter, while allowing for efficient gap spanning and increased travel speeds.
Implementation Method 1
Electrical power is applied to the welding wire and a circuit is completed through the workpiece to sustain an arc that melts the wire and the workpiece to form the desired weld
Implementation Method 2
current and/or voltage pulses are commanded by the power supply control circuitry to regulate the formation and deposition of metal droplets from the welding wire, to sustain a desired heating and cooling profile of the weld pool
Data Source
AI summary
A pulsed welding regime includes a peak phase 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 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. 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.