comparison of fmc/tfm and phased array ultrasonic … · paut thin wall in: iso 20601 • both...
TRANSCRIPT
© 2019 Eddyfi Technologies
COMPARISON OF FMC/TFM AND PHASED ARRAY
ULTRASONIC TESTING OF WELDS IN THIN WALLED
MATERIALS
CASPER WASSINK, EDDYFI & KAROLINA GALON, MISTRAS
Content
1. General introduction
2. ISO 20601 vs ISO DIS 23864
3. Procedure development
4. Testing results
5. Conclusions
ISO system structure
FMC/TFM in:
ISO DIS 23865 (general technique)
ISO DIS 23864 (weld testing)
PAUT thin wall in:
ISO 20601
• Both standards have same lower
Wall Thickness limit of 3.2mm
• Many textual similarities
WHERE ARE FMC/TFM AND PAUT?
FMC/TFM standardization status
FMC/TFM is now recognized within the NDT community
• More than a decade since first publications began to emerge
• Almost all papers at ECNDT 2018 in the Phased Array sessions were actually on
FMC/TFM
• each paper started with the same 5 minute explanation of how FMC/TFM works
• Confusion on name getting to an end: IWEX, SPA, TFM etc. basically all the same thing
• First standards have been developed
• ASME special working group on FMC, Paul Hayes (chair), Kimberley Hayes (vice chair)
• IIW working group on FMC/TFM, Daniel Chauveau (chair), Casper Wassink (vice chair)
• Significant exchange between the two committees
What is FMC
FMC: Full Matrix Capture
Pulse with one element, receive with all
Repeat until all elements are fired
N emitters
N r
eceiv
ers
What is TFM
TFM: Total Focussing Method
𝑠𝑛1 𝑡 … 𝑠𝑁1 𝑡…
1. Define a region of interest in the component
2. Time-of-flight calculation for all tx-rx combinations
Px
𝐸i 𝑅j
3. Amplitude extraction from each signal at time tij(P)
4. Sum of the N x N amplitudes
5. Perform the steps above for all pixels
N emitters
N r
eceiv
ers
𝑡𝑖𝑗 = 𝑡𝐸𝑖𝑃 + 𝑡𝑃𝑅𝑗
Aij
Px
Which time of flight?
WHAT PATH DO WE ASSUME FOR THE ULTRASOUND
ISO 20601 versus ISO DIS 23864 – 4. Testing levels
ISO 20601
MAIN DIFFERENCES REGARDING PROCEDURE DEVELOPMENT
ISO DIS 23864
Next slide
Testing level table ISO DIS 23864
KEEPING THE BALANCE BETWEEN TECHNIQUES
ISO 20601 versus ISO DIS 23864 – 6. Personnel and equipment
ISO 20601
6.1. skills listed as suggested by Phase A of
the KINT project for acceptance criteria
6.2.3. Suitable search unit frequency
MAIN DIFFERENCES REGARDING PROCEDURE DEVELOPMENT
ISO DIS 23864
6.1. General formulation regarding knowledge
needed
6.2.2. Suggested special resolution of image
6.2.3. General properties to take into consideration
7.2.2. Suggested imaging paths for defect types
ISO 20601 versus ISO DIS 23864 – 9. Gain Correction
ISO 20601
General TCG of DAC approach
MAIN DIFFERENCES REGARDING PROCEDURE DEVELOPMENT
ISO DIS 23864
Similar gain correction based on the TFM
image of the side drilled holes
Verification of the image grid
(ISO DIS 23865 annex C)
See also next slide
ISO DIS 23865 – grid verification
MOVING THE PROBE IN 0.1MM STEPS
33mm x 33mm grid, 5 MHz Probe
0.26mm grid increment (λ/5)
164mm x 164mm grid, 5 MHz Probe
0.64mm grid increment (λ/2)
0
20
40
60
80
100
120
0 0.2 0.4 0.6 0.8 1 1.2
Amplitude (λ/5 grid increment)
0
20
40
60
80
100
120
0 0.2 0.4 0.6 0.8 1 1.2
Amplitude (λ/2 grid increment)
Test setup
SAMPLE AND PROBES
3.2mm Wall Thickness
4” diameter
Olympus 10CCEV35 probes
10 MHz, 0.3mm pitch
Jireh Rotix chain scanner
Same probe position for PAUT
and FMC/TFM
Set-up dialog
TFM settings
Setting the region of interest
Defect 1
RT
Defect 1
PAUT
Defect 1
FMC/TFM
Defect 1
COMPARISON OF IMAGES
Defect 2
RT
Defect 2
PAUT
Defect 2
FMC/TFM
Defect 2
COMPARISON OF IMAGES
Defect 3
RT
Defect 3
PAUT
Defect 3
FMC/TFM
Defect 3
COMPARISON OF IMAGES
Conclusion
Standards for FMC/TFM are now available, ISO standard in DIS stage
In the standardization process, several properties of FMC/TFM are now
better understood
Setting up FMC/TFM to ISO DIS 23864 is straight forward
Even with a non-optimized setup, FMC/TFM creates images with much better
resolution than PAUT. This is a benefit for testing welds in low wall thickness
components