Speaker
Description
Introduction
Understanding the stress distribution on the surface of a welded sample is crucial for evaluating the structural integrity of the product and ensuring the safe operation of industrial components. Measuring stress in such material can be done by utilizing Barkhausen effect phenomenon. During sample magnetization, movement of magnetic domain walls (DW) causes generation of Barkhausen noise (BN) signal. External and residual stresses cause modification of domain wall structure, modifying the BN signal which allows for correlation between signal and stress distribution.
Results and discussion
In this work, MagStress BURN measurement set equipment was used. Wedge shaped probe with detecting coil wound on a 1 mm diameter core, was used to test surface of welded sample. Multiparameter BN analysis software, provided 16 descriptors that were derived from different signal features.
Robotic arm provided with MagStress BURN allows for movements with 0.1 mm accuracy. This pairing allows for high-resolution testing and imaging of samples. Mesh of points with resolution of 0.5mm over 20x18mm area provides 1440 data points. This covers 3 electron welds and heat-affected zone (HAZ).
Chosen descriptor peak values corelate with location of electron welds present in the sample. Values over different welds vary, which can be explained by weld fabrication process. Subsequently placed welds cause relaxation process to occur where the first weld is relaxed by next welds. Analysing obtained values, we can also see that HAZ generated in this process is extremely small compared to traditional welding methods. This combined with small weld surface necessitates usage of high-resolution measurement techniques.
Presented system allows for near instant evaluation of ferromagnetic samples thus combining non-destructive evaluation with rapid diagnostics not available with other testing apparatuses.
Acknowledgements: Proprietary system for inspecting the surface condition of ferromagnetic steel products intended for operation in conditions with increased strength requirements; Polish grant POIR.01.01.01-00-1168/21
| Speaker Company/University | Gdańsk Univeristy of Technology |
|---|