Adaptive SAW Waveform Balance for Penetration and Crack Control
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Solution Overview
Problem
Conventional submerged arc welding (SAW) processes face challenges in maintaining optimal penetration depth and deposition rate while avoiding hot cracks, which can lead to reduced productivity and mechanical property issues in the heat-affected zone (HAZ).
Innovation Solution
The method involves real-time monitoring of the SAW operation to detect discrepancies between desired and actual weld parameters, and then controlling the power supply to adjust the balance or offset of the alternating current (AC) welding power signal to compensate for these discrepancies, thereby modifying the deposition rate and penetration without changing the heat input.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If operating parameters (current, voltage, wire feed speed) are maintained at low levels to avoid hot cracks, then weld safety and crack prevention are improved, but penetration depth and deposition rate decrease, reducing productivity
Solution Approach 1:
The patent changes the waveform parameters of the AC power signal by adjusting balance and offset. This modifies the current distribution pattern during welding without changing the overall heat input, enabling increased deposition rate while maintaining crack prevention safety margins
Solution Approach 2:
The patent implements real-time monitoring and dynamic adjustment of AC power signal parameters. The system continuously adapts the balance and offset values based on actual welding conditions, allowing the deposition rate to be optimized while maintaining crack-free welds throughout the welding process
2Productivity
If operating parameters are increased to improve penetration depth and deposition rate, then productivity is improved, but the risk of hot cracks and surface-breaking cracks increases
Solution Approach 1:
The patent modifies the AC power signal waveform parameters (balance and offset) to change the current distribution pattern. This enables achieving deeper penetration without proportionally increasing the risk of hot cracks, as the modified waveform distributes current more favorably during the welding process
Solution Approach 2:
The patent employs real-time monitoring of welding parameters and uses this feedback to dynamically adjust the AC power signal balance and offset. This closed-loop control ensures that penetration depth is maximized while maintaining parameters within safe margins to prevent crack formation
3Manufacturing precision
If active parameters (current, voltage, travel speed) are changed to maintain desired weld fill, then weld geometry control is improved, but heat input changes, affecting mechanical properties of the heat-affected zone
Solution Approach 1:
The patent changes the waveform parameters (balance and offset) of the AC power signal rather than changing active parameters like current, voltage, or travel speed. This allows precise control of weld fill and geometry while keeping the overall heat input constant, thereby preserving the mechanical properties of the heat-affected zone
Solution Approach 2:
The patent segments the control approach by separating geometry control (achieved through balance and offset adjustment) from heat input control (maintained through constant active parameters). This segmentation enables independent optimization of weld geometry without affecting HAZ mechanical properties
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 allows for real-time adjustments to achieve higher deposition rates and penetration depths while maintaining consistent mechanical properties in the HAZ, thus enhancing productivity and weld quality.
Implementation Method 1
a power supply to supply alternating current (AC) welding power signal to the welding wire to create a molten weld pool on the workpiece
Implementation Method 2
The weld current forms an arc between the welding wire and the workpiece to create a molten weld pool on the workpiece
Implementation Method 3
The weld current forms an arc between the welding wire and the workpiece
Data Source
AI summary
A method includes monitoring a submerged arc welding (SAW) operation in real-time; determining, based on the monitoring and in real-time, a discrepancy between a desired weld parameter and an actual weld parameter of a weld resulting from the SAW operation; and in response to determining the discrepancy, controlling a power supply, which provides power for the SAW operation, to modify at least one of balance or offset of an alternating current (AC) welding power signal supplied for the SAW operation to compensate for the discrepancy.