Abstract
Surface cracks can develop in components due to residual stresses, fatigue, stress corrosion cracking, corrosion fatigue, etc, during service exposure. Different non-destructive testing (NDT) methods are employed to detect and monitor such cracks. Magnetic Barkhausen Noise (MBN) analysis is one such technique that is used for in situ examination of microstructural anomalies or stress patterns. In the present work, we study the applicability of MBN for the detection of surface cracks. A part through surface crack was created by controlled fatigue loading of a martensitic stainless steel plate. The surface of the sample was scanned for BN emissions in incremental steps parallel and perpendicular to the crack. Measurements of MBN signal strength were recorded and assessed. Localized peaks in the MBN values observed whilst scanning sample surface can reveal the presence of flaws. Furthermore, the remnant stress pattern ahead of the crack tip as well as in the wake of the crack can get reflected in the measured MBN values. The observations carried out show that the surface scan carried out with MBN measurements can be a good non-destructive method for in situ NDT to detect and characterize surface cracks.
Highlights
Surface cracks constitute a type of flaw that can grow to critical size during service of an equipment and can become precursors to premature failures.1 For timely corrective action, such flaws need to be detected, characterized, evaluated and repaired to ensure continuing safety of installations
Anomalies in otherwise uniform Magnetic Barkhausen Noise (MBN) values covering the sample surface can be detected in the C-scan representation thereby revealing the presence of the bands of plastic zone and of the surface cracks
A part through surface crack was introduced by subjecting the sample to fatigue loading on a 100 KN MTS in a three point bend mode to generate a crack about 10 mm long in the center of the sample surface
Summary
Surface cracks constitute a type of flaw that can grow to critical size during service of an equipment and can become precursors to premature failures. For timely corrective action, such flaws need to be detected, characterized, evaluated and repaired to ensure continuing safety of installations. Surface cracks constitute a type of flaw that can grow to critical size during service of an equipment and can become precursors to premature failures.. Cracks are associated with characteristic stress patterns that depend on their size, configuration, location, loading regime and material properties. Considerable research has been undertaken and carried out using stress analysis methods as well as experimental methods to analyze and understand the stress patterns associated with cracks in different situations.. Barkhausen emissions are sensitive to microstructure, stress environment, chemical inhomogeneity, grain size, surface or near surface stresses resulting from static or dynamic loading.. Barkhausen noise measurements will be used to detect and characterize residual stress patterns in the plastic zone of a part through crack in a steel sample
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
