Pulsed Welding Waveform Control to Reduce Micro-Arcing

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Solution Overview

Problem

Current welding processes, particularly in MIG welding, face challenges in minimizing micro-arcing between the welding wire and the torch contact tip, which can degrade the welding operation and affect the quality of welds, especially with flux-cored or metal-cored welding wires that have low manganese content.

Innovation Solution

A welding method and system that generate a control waveform with successive peak phases of voltage and current, followed by a transition phase and a background phase, where the ratio of background current to peak current is at least 25% and the ratio of background voltage to peak voltage is at least 50%, to regulate and smooth the welding power output and avoid micro-arcing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional pulsed welding regimes are used, then welding wire melting and deposition are achieved, but micro-arcing occurs between the welding wire and contact tip

Engineering Contradiction:
Improveweld qualityVSAvoidmicro-arcing
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies periodic action by using a control waveform with repeated cycles of peak phases followed by background phases. This periodic waveform structure allows the welding process to alternate between high-power melting phases and lower-power deposition phases, preventing continuous micro-arcing while maintaining effective wire melting and deposition through the cyclic nature of the power delivery.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent employs parameter changes by dynamically varying the voltage and current parameters throughout the welding cycle. The control waveform modifies electrical parameters in real-time, transitioning between peak voltage/current for melting and background voltage/current for deposition, thereby controlling the arc behavior to eliminate micro-arcing while preserving weld quality.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If background current and voltage ratios are increased to reduce micro-arcing, then micro-arcing is minimized, but welding power output regulation becomes more complex

Engineering Contradiction:
Improvemicro-arcingVSAvoidwaveform control
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the welding power output into distinct phases: peak phases for melting and background phases for deposition. Each phase has specific voltage and current characteristics, allowing independent optimization of parameters to reduce micro-arcing while maintaining manageable control complexity through the structured separation of functional phases.

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If sophisticated pulsed welding regimes are developed for specific materials and conditions, then weld quality is improved, but the complexity of the welding process increases

Engineering Contradiction:
Improveweld qualityVSAvoidwelding process control
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by creating a control waveform structure that can be applied across different welding conditions and materials. The multi-phase waveform design provides a versatile framework that adapts to various welding scenarios while maintaining consistent benefits in reducing micro-arcing and improving weld quality, thereby achieving high manufacturing precision without proportionally increasing process complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 effectively reduces micro-arcing and enhances the melting and deposition of welding wire, improving the quality and consistency of welds by maintaining higher background current and voltage levels compared to conventional pulsed welding regimes.

Implementation Method 1

Electrical power is applied to the welding wire and a circuit is completed through the workpiece to sustain an arc

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

sustain an arc that melts the wire and the workpiece to form the desired weld

Methodology Applied
Scientific EffectElectric arc: Electric Arc

Implementation Method 3

Transform Electrical Energy to Thermal Energy

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

provide for flow of the material, combined metallurgy, and other useful characteristics both during the welding process

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3383572B1Welding system and method
Publication Date: 2023.06.21 ILLINOIS TOOL WORKS INC
  • EP3383572B1 patent drawingFigure 1
  • EP3383572B1 patent drawingFigure 2
  • EP3383572B1 patent drawingFigure 3

AI summary

A welding system and method provide for generating a controlled waveform for welding power output, the waveform comprising a plurality of successive peak phases (84) designed to avoid or reduce micro-arcing when used with metal-cored or flux-cored electrode wires. Ratios of the background current and voltage levels are elevated as compared to conventional techniques, with the levels in most cases exceeding 50% of the peak currents and voltages. Transitions between background and peak levels of current and voltage are also smoothed (88), and the duration of the peak phase as compared to the duration of each pulse cycle is elongated to further reduce micro-arcing.