Rayleigh Wave Weld Bead Inspection During Multi-Pass Deposition
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Solution Overview
Problem
Current nondestructive inspection techniques for weld beads, such as radiography and ultrasound, are inefficient and prone to defects due to the need for multiple stages of inspection, temperature limitations, and the use of coupling fluids that can affect weld quality, especially in high-temperature environments and multi-pass welds.
Innovation Solution
A method using movable electromagnetic acoustic sensors that emit Rayleigh surface waves to inspect weld beads in real-time during deposition, eliminating the need for coupling fluids and allowing inspection at high temperatures, with the ability to detect defects throughout the entire weld volume and adapt welding parameters in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If radiographic inspection is performed in two stages (intermediate and final), then weld quality is ensured, but productivity is reduced and cycle time is lengthened by 15-20 minutes per weld
Solution Approach 1:
The patent performs preliminary inspection during the welding process itself (intermediate inspection) using electromagnetic acoustic sensors to detect defects in real-time, eliminating the need for separate post-welding inspection stages. The welding process includes intermediate pause periods where inspection is conducted before the weld is complete, allowing early detection of defects such as lack of penetration or improper fusion.
Solution Approach 2:
The inspection process is integrated into the continuous welding operation, with sensors positioned to inspect the weld bead as it is being deposited. The system maintains continuous monitoring capability throughout the welding process, including during intermediate pauses, rather than requiring discrete separate inspection operations. This continuous approach eliminates idle time between welding and inspection.
2Reliability
If conventional ultrasound sensors are used, then weld inspection is possible, but the surface temperature must be kept below 100°C and piezoelectric effect disappears above 200°C
Solution Approach 1:
The patent replaces conventional piezoelectric ultrasound sensors with electromagnetic acoustic sensors that use electromagnetic fields to generate and detect acoustic waves. This substitution eliminates the temperature limitation of piezoelectric materials, allowing inspection to be performed on hot welds without requiring the surface temperature to be below 100°C or 200°C. The electromagnetic sensing mechanism remains effective at elevated temperatures.
3Reliability
If water is used for ultrasound coupling, then inspection is enabled, but surface temperature cannot exceed 100°C due to water's boiling point
Solution Approach 1:
The patent extracts and eliminates the coupling fluid (water) from the inspection system by using electromagnetic acoustic sensors that do not require direct contact or coupling media with the workpiece surface. This removal of the coupling fluid constraint allows inspection to be performed on surfaces at any temperature, including temperatures above 100°C where water would boil and create air gaps that interfere with ultrasound transmission.
4Reliability
If multiple inspection stages are required, then comprehensive defect detection is achieved, but the inspection process becomes complex and time-consuming
Solution Approach 1:
The patent combines the welding process and inspection process into a single integrated operation. The electromagnetic acoustic sensors are positioned to inspect the weld bead during deposition, merging what were previously separate sequential operations (welding then inspection) into a concurrent process. This integration maintains comprehensive defect detection capability while eliminating the complexity and time associated with multiple separate inspection stages.
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 significantly reduces cycle time, improves productivity, and ensures high-quality welds by enabling real-time defect detection and correction during the welding process, while avoiding the limitations of traditional techniques like radiography and conventional ultrasound.
Implementation Method 1
the electromagnetic acoustic sensor for emitting ultrasound waves being configured to emit Rayleigh surface waves
Implementation Method 2
at least one reception electromagnetic acoustic sensor for receiving ultrasound signals
Data Source
AI summary
A method of automatically inspecting a weld bead deposited in a plurality of passes in a chamfer formed between two parts by performing the following steps: positioning at least one emission electromagnetic acoustic sensor on one side of the chamfer and at least one reception electromagnetic acoustic sensor on an opposite side of the chamfer, the ultrasound wave emission sensor being configured to emit Rayleigh surface waves; while depositing a pass, automatically moving the sensors to follow the movement of welding electrodes along the chamfer; activating the sensors while they are moving to enable the emission sensor to generate and emit Rayleigh waves towards the pass of the weld bead that is being deposited, the reception sensor receiving the ultrasound signals transmitted and/or reflected in said pass; and reiterating the operation for the entire pass of the weld bead.