Weld defect detection using PPM EMAT generated shear horizontal ultrasound

Abstract Austenitic welds are inspected using PPM EMAT generated shear horizontal (SH) waves. Results are compared to measurements taken using a 1D piezoelectric phased array using the total focusing method (TFM). For the first time there is clear experimental evidence of the SH wave method demonstrating higher sensitivity to defect detection. SH waves suffer less beam steering in a weld than either compression or SV waves, which can miss defects due to weld microstructure anisotropy and attenuation. All defects were identified from every side of the weld/plate using the SH waves, but this was not possible using the piezoelectric transducer.

[1]  Stephen Dixon,et al.  Laser-EMAT system for ultrasonic weld inspection , 1999, Smart Structures.

[2]  P. Wilcox,et al.  Post-processing of the full matrix of ultrasonic transmit-receive array data for non-destructive evaluation , 2005 .

[3]  R. B. Thompson.  Physical Principles of Measurements with EMAT Transducers , 1990 .

[4]  C. M. Fortunko,et al.  Ultrasonic inspection of stainless steel butt welds using horizontally polarized shear waves , 1982 .

[5]  M. G. Silk,et al.  The potential of scattered or diffracted ultrasound in the determination of crack depth , 1975 .

[6]  Hirotsugu Ogi,et al.  Electromagnetic acoustic resonance and materials characterization , 1997 .

[7]  J. Ogilvy.  Ultrasonic beam profiles and beam propagation in an austenitic weld using a theoretical ray tracing model , 1986 .

[8]  K Sawaragi,et al.  Improvement of SH-wave EMAT phased array inspection by new eight segment probes , 2000 .

[9]  M. G. Silk,et al.  Ultrasonic Transducers for Nondestructive Testing , 1984 .

[10]  H. Ogi,et al.  EMATs for Science and Industry: Noncontacting Ultrasonic Measurements , 2010 .

[11]  J. Rose.  Ultrasonic Waves in Solid Media , 1999 .

[12]  Christopher Edwards,et al.  Texture measurements of metal sheets using wideband electromagnetic acoustic transducers , 2002 .

[13]  Steve Dixon,et al.  Ultrasonic metal sheet thickness measurement without prior wave speed calibration , 2013 .

[14]  C. F. Vasile,et al.  Excitation of horizontally polarized shear elastic waves by electromagnetic transducers with periodic permanent magnets , 1979 .

[15]  Masahiro Nishikawa,et al.  Fundamental experiment for inspection of cooling pipes in operation by using ultrasonic technique , 2006 .

[16]  S. P. Clark,et al.  APPLICATION OF LARGE APERTURE EMATS TO WELD INSPECTION , 2008 .

[17]  Tatsuo Miyazawa,et al.  Development of Ultrasonic Testing Equipment Incorporating Electromagnetic Acoustic Transducer , 1989 .

[18]  D. O. Thompson,et al.  Review of Progress in Quantitative Nondestructive Evaluation , 1985 .

[19]  Bao Mi,et al.  Real-Time Weld Penetration Depth Monitoring With Laser Ultrasonic Sensing System , 2006 .

[20]  S B Palmer,et al.  High accuracy non-contact ultrasonic thickness gauging of aluminium sheet using electromagnetic acoustic transducers. , 2001, Ultrasonics.

[21]  Jr. S. Marple,et al.  Computing the discrete-time 'analytic' signal via FFT , 1999, Conference Record of the Thirty-First Asilomar Conference on Signals, Systems and Computers (Cat. No.97CB36136).

[22]  R. M. Panos,et al.  Electromagnetic generation of electronically steered ultrasonic bulk waves , 1976 .

[23]  Huidong Gao,et al.  INSPECTION OF AUSTENITIC WELD WITH EMATS , 2010 .

[24]  Gerd Dobmann,et al.  Emat Pipe Inspection with Guided Waves , 2012, Welding in the World.

[25]  Hirotsugu Ogi,et al.  Increase of Efficiency of Magnetostriction SH-Wave Electromagnetic Acoustic Transducer by Angled Bias Field: Piezomagnetic Theory and Measurement , 2003 .

[26]  H. Grubin.  Direct Electromagnetic Generation of Compressional Waves in Metals in Static Magnetic Fields , 1970, IEEE Transactions on Sonics and Ultrasonics.

[27]  Katsuhiro Kawashima,et al.  Theory and numerical calculation of the acoustic field produced in metal by an electromagnetic ultrasonic transducer , 1976 .

[28]  H. Ogi,et al.  An SH-wave EMAT technique for gas pipeline inspection , 1999 .

[29]  Klas Weman,et al.  Welding Processes Handbook , 2003 .

[30]  Inspection of dissimilar metal welds using horizontally polarized shear (SH-)waves and electromagnetic ultrasonic (EMUS-) probes , 1989 .

[31]  H. Ogi.  Field dependence of coupling efficiency between electromagnetic field and ultrasonic bulk waves , 1997 .

[32]  J. A. G Temple,et al.  Engineering applications of ultrasonic time-of-flight diffraction , 1989 .

[33]  Jessika Schulze,et al.  Laser Ultrasonics Techniques And Applications , 2016 .