Arc Welding Cycle Control for Stable Beads and Low Spatter
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing arc welding methods with consumable electrodes face issues of spattering and non-uniform bead appearance due to discontinuous control of wire feeding and welding current during transitions between short-circuit and pulse welding periods, leading to unstable heat input and burn-through or insufficient melting.
Innovation Solution
A method that alternates between short-circuit welding, pulse welding, and cooling periods, with the welding wire fed in alternating forward and backward directions during short-circuit welding and at a constant speed during pulse welding, and includes a cooling period with zero heat input to control bead geometry and prevent spattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If short-circuit welding is used to reduce heat input and prevent burn-through, then burn-through is reduced, but spattering increases due to irregular short circuits and humped beads form
Solution Approach 1:
The patent applies periodic action by alternating between short-circuit welding periods and pulse welding periods in a cyclic manner. During short-circuit periods, the wire is fed forward at high speed to create short circuits with low heat input, preventing burn-through. During pulse periods, the wire feeding is temporarily stopped or reversed while high current pulses are applied to melt the wire tip and form droplets. This periodic alternation allows the system to achieve both low heat input (preventing burn-through) and controlled droplet transfer (reducing spattering) by switching between two distinct welding modes.
2Reliability
If pulse welding is used to provide stable droplet transfer, then stable welding is achieved, but heat input is too low causing undercuts in thin-plate welding
Solution Approach 1:
The patent uses periodic action to alternate between pulse welding periods (providing stable droplet transfer) and short-circuit welding periods (providing higher heat input). During pulse periods, stable current control ensures reliable droplet formation and transfer. During short-circuit periods, the natural short-circuiting action provides higher peak currents that increase heat input to prevent undercuts. The cyclic alternation between these two modes allows the system to simultaneously achieve stable droplet transfer and sufficient heat input.
3Object-generated harmful factors
If wire feeding is controlled discontinuously during transitions between welding periods, then spattering is reduced, but welding stability decreases and scaly beads become non-uniform
Solution Approach 1:
The patent applies dynamics by making the wire feeding speed variable and continuously adjustable during different phases of the welding cycle. During short-circuit periods, the wire feeding speed is increased to promote frequent short circuits. During pulse periods, the feeding speed is reduced or reversed to allow droplet formation. The transition between these states is performed dynamically with smooth speed changes rather than abrupt stops, maintaining arc stability. The feeding speed is modulated in real-time based on the welding phase, allowing the system to reduce spattering while maintaining welding stability and uniform scaly bead appearance.
4Reliability
If high heat input welding condition is used to ensure stable arc, then arc stability is improved, but burn-through occurs
Solution Approach 1:
The patent uses periodic action to alternate between high heat input conditions (during short-circuit periods) and low heat input conditions (during pulse periods). During short-circuit periods, high current provides stable arc and sufficient heat input. During pulse periods, the current is reduced or pulsed at lower levels, reducing heat input to prevent burn-through. The cyclic alternation allows the arc to experience periods of high energy input for stability and periods of low energy input to prevent excessive heating, achieving both arc stability and prevention of burn-through through time-averaged heat input control.
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 method achieves precise control of heat input, reducing spattering and ensuring a stable arc for producing scaly beads with a beautiful wave pattern by alternating welding periods and maintaining consistent wire feeding speeds.
Implementation Method 1
arc welding in which an arc is generated between a welding wire, which is a consumable electrode and a base material
Data Source
AI summary
A method of controlling arc welding with a consumable electrode includes repeating the following periods in sequence: a short-circuit welding period to perform short-circuit arc welding; a pulse welding period to perform pulse welding; and a cooling period in which the welding current output is zero.