Laser Weld Inspection After Surface Cleaning for Defect Detection
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Solution Overview
Problem
Existing welding inspection methods fail to accurately detect internal defects in welds due to interference from impurities such as slag on the weld surface during laser ultrasound generation.
Innovation Solution
A method that involves removing impurities from the weld surface before laser ultrasound inspection using a surface treatment apparatus or laser ablation, followed by scanning with transmission laser light to generate ultrasound and detecting reflections for defect detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission laser light is irradiated directly onto the weld surface, then the inspection process is simple and fast, but impurities such as slag on the surface interfere with ultrasound generation and cause defective inspection
Solution Approach 1:
The patent applies preliminary action by removing impurities from the weld surface before performing the laser ultrasound inspection. The surface treatment apparatus cleans the inspection area in advance, ensuring that the subsequent laser irradiation occurs on a clean surface, thereby preventing interference with ultrasound generation and ensuring reliable defect detection.
2Measurement precision
If a surface treatment apparatus is used to remove impurities before inspection, then detection accuracy is improved, but the inspection process becomes more complex
Solution Approach 1:
The patent merges the surface treatment function with the inspection system by integrating a surface treatment apparatus into the welding inspection setup. This combination allows the system to perform both surface cleaning and defect detection in a unified workflow, improving reliability while managing complexity through functional integration.
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
Enables accurate detection of internal defects in welds even when impurities are present, ensuring reliable inspection results.
Implementation Method 1
irradiation from above a weld bead, of a bead surface with transmission laser light and detection of ultrasound (scattered waves) reflected by the defect
Implementation Method 2
A method that involves removing impurities from the weld surface before laser ultrasound inspection using a surface treatment apparatus or laser ablation
Data Source
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AI summary
The present application relates to a welding inspection method, which includes a step (S102) of removing an impurity at a surface of a weld with a surface treatment apparatus, a step (S110) of irradiating the surface of the weld from which the impurity has been removed with transmission laser light, a step (S120) of detecting reflected ultrasound reflected by a lower surface of a base material, and a step (S150) of determining whether or not there is an internal defect in the weld based on a result of detection of reflected ultrasound.