Arc Welder Pulse Control for Galvanized Steel Defects
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Solution Overview
Problem
Conventional arc welding methods for galvanized steel plates face issues with the formation of blowholes and pits due to insufficient diffusion of vaporized zinc, leading to weakened welds, and struggle to adjust peak currents for different joint types, resulting in excessive spatter.
Innovation Solution
An arc welder that alternately repeats short circuit and arc periods, with a joint type setting section, storage of waveform parameters, and a determining section to adjust welding output based on the joint type, ensuring appropriate peak currents for each joint type to prevent blowholes and spatter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If high peak current is used to press the melt pool strongly, then the arc force presses the melt pool effectively, but the welding object is dented and hole openings (burn-through) can be formed
Solution Approach 1:
The patent applies periodic action by using pulse MAG welding with alternating current flow directions. The current is applied in pulses with specific on-time and off-time periods, creating periodic heating and cooling cycles that allow the melt pool to be pressed effectively during the on-period while preventing burn-through during the off-period. This periodic current application resolves the contradiction between needing strong arc force and preventing welding object damage.
Solution Approach 2:
The patent changes the current parameter by reversing the current direction periodically between forward and backward feeding modes. By controlling the current direction and magnitude dynamically, the system achieves effective melt pool pressing when needed while preventing excessive penetration. The current parameters (amplitude, duration, direction) are adjusted based on the welding state to resolve the force-strength contradiction.
2Strength
If low peak current is used to prevent micro short circuit and melt pool denting, then welding object integrity is maintained, but micro short circuit may still occur and arc force is insufficient
Solution Approach 1:
The periodic pulse current application ensures that during the on-period, sufficient current is applied to maintain arc stability and prevent micro short circuits, while during the off-period, the current is reduced to prevent melt pool denting. This temporal separation of functions resolves the contradiction between maintaining arc stability and preventing welding object damage.
Solution Approach 2:
The system dynamically adjusts the current parameters based on the welding state and phase (forward or backward feeding). The current magnitude and direction are changed in real-time to match the required arc force while maintaining welding object integrity. This dynamic control allows the system to adapt between preventing micro short circuits and avoiding excessive penetration.
3Ease of manufacture
If conventional short circuit transfer welding is used, then welding process is simple, but air holes remain in weld bead causing blowholes and pits that damage welding strength
Solution Approach 1:
The patent utilizes phase transitions by controlling the melting and solidification cycles of the weld metal through periodic current application. The alternating current creates controlled melting during the on-period and solidification during the off-period, allowing vaporized zinc to escape during solidification phases. This controlled phase transition process prevents air hole formation while maintaining welding strength, improving upon simple short circuit welding.
Solution Approach 2:
The patent employs a composite welding approach combining MAG welding with pulse current control and alternating feeding directions. This composite method integrates multiple control mechanisms (current direction, current magnitude, pulse timing) to achieve both defect-free welding and maintained strength, surpassing the simplicity of conventional methods while delivering superior welding quality.
4Reliability
If peak current is increased to prevent micro short circuit, then arc stability improves, but excessive spatter occurs
Solution Approach 1:
The periodic pulse current application provides sufficient current during the on-period to maintain arc stability and prevent micro short circuits, while the off-period allows the arc to rest and reduces spatter generation. This temporal modulation of current resolves the contradiction between maintaining arc stability and minimizing spatter loss.
Solution Approach 2:
The patent applies current in controlled pulses rather than continuously, using partial action (intermittent current application) to achieve the necessary arc stability only when needed. This prevents excessive current application that would cause spatter, while still providing sufficient current during active welding phases to maintain arc stability.
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 suppresses blowhole and pit formation by releasing vaporized zinc without causing burn-through, ensuring strong welds and minimizing spatter across various joint types.
Implementation Method 1
an arc occurs between the wire and the welding object
Implementation Method 2
the vaporized zinc starts to diffuse to the outside through a melt pool
Implementation Method 3
perform welding by alternately generating a short circuit state and arc state while repeating the forward feeding and backward feeding
Data Source
AI summary
An arc welder alternately repeats a short circuit period in which a wire and a welding object are short-circuited and an arc period in which an arc occurs between the wire and the welding object. The arc welder includes a welding output section, a joint type setting section, a storage section, and a waveform parameter determining section. The welding output section performs welding output, and the joint type setting section sets a joint type. The storage section stores a plurality of combinations of joint types and waveform parameters. The waveform parameter determining section determines a waveform parameter based on the joint type set by the joint type setting section and the plurality of combinations. The welding output section performs welding output based on the waveform parameter determined by the waveform parameter determining section. Thus, vaporized zinc is easily released and sufficient welding is performed.