A Water Environment-Based Simulated Method for Ultrasonic Testing of Slag Inclusion Weld Defects Based on Improved...

Area of Science:

• Materials Science
• Non-destructive Testing
• Mechanical Engineering

Background:

• Slag inclusion defects critically impact weld integrity and safety.
• Limited research exists on categorizing slag inclusion materials, hindering quality control.
• Accurate identification of slag types is crucial for engineering safety and personnel well-being.

Purpose of the Study:

• To develop a simulated ultrasonic testing method for identifying slag inclusion material categories in austenitic stainless steel.
• To address the research gap in classifying different types of slag inclusions.
• To enhance the reliability and safety of welded structures through improved defect characterization.

Main Methods:

• Simulated experiments in a water environment using six categories of cubic specimens (four metallic, two non-metallic).
• Variational mode decomposition optimized by particle swarm optimization for ultrasonic signal denoising.
• Phase spectrum analysis of denoised signals to extract phase characteristics from the water-slag interface echo.

Main Results:

• The proposed denoising method demonstrated appropriate decomposition and effective performance.
• Achieved the highest signal-to-noise ratio and lowest normalized cross-correlation compared to other algorithms.
• Successfully extracted the fewest intrinsic mode functions, indicating superior denoising.
• Phase spectrum analysis accurately determined if slag inclusions were thicker or thinner than the base material.

Conclusions:

• The developed ultrasonic testing method effectively identifies slag inclusion material categories in austenitic stainless steel.
• The optimized variational mode decomposition and phase spectrum analysis offer significant improvements in signal denoising and defect characterization.
• This approach enhances the capability to safeguard engineering quality and personnel safety in welded structures.