Nondestructive Material Testing with Ultrasonics

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Nondestructive Material Testing with Ultrasonics
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?????Non Destructive Testing??

• Radiography Testing (RT)
• Ultrasonic Testing (UT)
• Visual Testing (VT)
• Penetrant Testing (PT)
• Magnetic Testing (MT)
• Eddy Current Testing (ECT)
• Hydraulic Testing (HT)

????? ?? ???? ???? ??? ??? ??, ????? ??? ????
????? ??? ???? ??(??)?? ?? ?? ??, ???? ?? ?? ??
???? ????
???? MT, ET ?? ?? ??
?????? MT, ET ?? ?? ??
???? UT, RT RT(?), UT(?) ????, ???
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??? ??? ???
1. ??

-?? ? ????? ????? RT?? ????. ????? ? ?? ?????
??? ????,????? ????? ????. -????? ????. -?????
??,??,??? ?? ?? ??? ??? ???. -????? ????? ?? ?? ?
? ??. -??? ?? ???? ?? ??? ??. -???? ????.
2. ??

• -????? ??? ?? ????.
• ???? ????? ?? ????? ??? ??? ???? ? ? ??? ???
  ??(?????? ?????? ??? ??)? ??? ?? ????? ??? ???
  ??? ?????,????? ????? ?????.
• -???? ? ???? ??? ??? ??.
• -???? ?? ???,??,??,??????? ??? ??? ???? ??? ??.
• ??? ????? ??? ?? ??? ??.
• ???? ??? ??? ?? ????? ????.

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???(Ultrasonic)??
Ultrasonic (ultrasound) ???? ???? ???? ?? ????

??? ??? 'Ultrasonic' or 'Ultrasound'? ?.
The ultrasonic principle is based on the face
that solid materials are good conductors of
sound waves.
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??? ????
?? (attenuation) ???? ??? ??
??? ? ???? ??? ??
??(scattering)?
??(absorption)
? ? ???? ??.
??? (resolution) ??? ??? ??? ?? ? ? ?? ??.
? ??? ?? ? ???? ???.
??? ? ???? ??? ?? ???? ???.
?? (?) ?? ??? ???
High frequency ? ????(?) ? ? ? (??????)
Low frequency ? ????(?) ? ? ? (??????)
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???? ??
??(longitudinal wave) ???? ????? ??? ????? ???
?.
???, ??? ??? ?.
???? ??? ?? ??? ???? ??.
??? ???? ??.
??(transverse wave) ???? ????? ??? ????? ???
?.
shear wave.
????? 50 ??? ??? ??.
????? ???? ??? ???? ???? ??.
???(surface wave) ??? ??? ?? ???? ?.
Rayleigh
wave.
????? 90 ??? ??? ??.
??? ??? ???? ??.
??(lamb wave) ?? ? ??? ????? ??
guided wave.
???, ?????
??.
Wave mode sample
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???(surface wave)
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?? ???
? ? ?
?? ?? ??? (Hz)
?? ???? 20KHZ ???? ???
?? ???? 20KHZ ???? ???
?? ???? 20KHZ ???? ???
???????? Probe?? ??? ??? ??? ???? ???? ??
??? (USN 60) ??? (Probe) ???? (Couplant) ????
(Tank)
???? ?? ???????
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???? ??? ??
Display (??????) ??? (??Pulse ??) ???
1
2
??? ??(?????)
3
4
5
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??? Pulse
???(???) Piezo-electric effect
Press
??? (??? ??)
??? ?? (?????)
? Steel ???, 5MHz ??? ???? ??? ?
Reflector Discontinuity Flaw
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Ultrasonic test ??
1. ????? ?? ?? ??? ???? ???? 2. ?? ??? ?? ???
?? 3. ???? ????? ??? ??? ?? ???? 4. ????? ???
???? ????? ??? ? ??.
S sound path mm
c sound velocity km/s
t transit time ?
Block diagram Pulse Echo method
The principle of time of flight measurement
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?????
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TOF time of flight (??? ???? ???? ???? ??)
Backwall Echo
?? ????
Initial Pulse
Flaw Echo
Flaw Echo
t ?? ????
????
Initial Pulse(Noise) ??? ??? ??? ? ? ??. S/N
Ratio (??? ???) 31 ( ??) 21 (?? ??)
Delay? Calibration?? ?? ? ?? ??
?? ??? ????? ????
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(No Transcript)
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Ultrasonic test ??
Initial pulse start
After 10 µs
Beam spot at the 8th scale graduation
Backwall echo at the 8th scale graduation
??? ????
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Discontinuities Echo
Test object with discontinuity, display with flaw
echo
Discontinuity in front of the backwall
Discontinuity near the surface
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?????? ??
????? ??? ???? ??, ??????? ???? ????? ?????? ???
??? ??? ?? ??????? ??? ??.
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?????? ??
???? ??? ??? ?? ???? ????? ????? ???? ??? ??? ???
?? ??? ?????, ???? ??? ??? ??? ??? ???? ????
???? ???? ???? ??? ?????,
?? ?? ? ???? ??
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?????? ??
?? ??? ???? ???? ????? ???? ????? ????? ???? ???
?? ????? ?? ??? ?? ????? ??? ??? ??
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Probe delay
straight beam probe - initial pulse delay
Angle beam probe - initial pulse delay
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Dead zone
Echo sequence of a near to surface discontinuity
A non-detectable near-to surface discontinuity
Shadowing of the backwall echo by a larger near
to surface reflector
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Transducer
straight beam probe
angle beam probe
Evaluation one echo - two possible reflector
locations
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???? ???? ? ????? ?? ??
?? ?? ???? ????
????? ? ? ????,??? ?? ?????? ? ????
????? ? ? ???,?? ?? ?? ??? ??
?????? ??? ????? ??? ????
??(L)
??(L)
L
L
Mode ?? ( L )
T
L
L
??
??
????
????
Steel ?? ?? (C1) 5920 mm/s
Steel ?? ?? (C2) 3250 mm/s
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?? ??
2 leg 1 skip
?? Crack ??? ??? ??. ??? skip 2, 3, 4,
1 leg
2 leg
?? Crack Direct? ??. 0.5 skip 1.5, 2.5, 3.5,
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?? ??
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?? ??
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(No Transcript)
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???? ??
1)??? ??
Ex1)??1? ???, ??2? ?(steel)? ? ??? ???? 90? ???
????.???? ??? ???? ????
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2. ????Mode conversion
??? ??? ??? ????? ?? ???? ??? ??? ???.

1? ???
2? ???
??? ???? 90? ?? ??? ?steel?? ??? ??
??? ???? 90? ?? ??? ?steel??? ???? ????.
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?? ??? ???

?1???
?2???
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TR probe (dual probe)
?? ??? ?? ?? ??? ??? ??? ? ?? Initial Pulse?
?? ? ? ??.
TR probe section
TR probe on the test object CRT with backwall
echo
Thickness measurement TR probe
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Calibration of the instrument Straight beam
probe
Echo No Sound path simm Scale factor k mm/scale grad Scale position Tiscale grad
1 25 10 2.5
2 50 10 5.0
3 75 10 7.5
4 100 10 10.0
1st Echo d
2st Echo 2d
3st Echo 3d, etc.
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Calibration of the instrument Angle beam probe
Sound path in the V1 block without angle
reflection
Path of a sound wave in a V2 block, radius
25mm And 100mm Calibration
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Angle beam test
Tandem testing - upper zone
Angle beam test
Surface crack test (angle beam probe)
Tandem testing - center zone
Plane vertical reflector near the surface
Tandem testing - lower zone
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Calibration (??? ??)
Basic Menu P-Delay Probe Delay Calibration? ? ??
Velocity ?? Calibration? ? ??
?? ??? Calibration
?? 8t?? 8.3t? ??? ? Why ? 1. ??? ??? Velocity?
???? ? 2. Probe Delay ?? ??? ?
8t
8.3 t
SBA B-A 8 1. Velocity? ???? SBA? 8? ???
SA 8 2. Probe Delay? ???? SA? 8? ???
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Calibration (??? ??)
Basic Menu P-Delay Probe Delay Calibration? ? ??
Velocity ?? Calibration? ? ??
?? ??? Calibration
1. ??? ?? 2. ??? ??
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Peak?? ?? ???
?????
12 mm
1. ???? ??? 12 mm ??? x-value
2. ???? ??? ???? Block? Angle? ??? ????? Peak??
Angle? ?????. (?? ???)
3. SA, SAB sa100, sab200?? ??? (????? ??)
4. ?? ????? Result?? Setting ?? ????. ?????
Peak? ???.
5. PA (Pass A ) ??? ???? RA (Reduced A)
Probe ???? ?? ?? DA (Depth A) ????
?????? ?? ???? ?? ? ? ?? DB (Depth B) ????
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Locating reflectors with an angle-beam probe
W0.5s t / cos ?
W1s 2 X W0.5s 2t / cos ?
Y0.5s t X tan ? W0.5s X sin ?
Y1s 2 X Y0.5s 2t X tan ? W1s X sin ?
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Locating reflectors with an angle-beam probe
The apparent depth
Reduced surface distances and X-value
The flaw triangle
The real reflector depth after sound reflection
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Evaluation of large discontinuities
Straight beam probe on the reflector boundary
A large reflector in the sound beam
Top view with reflector for extension
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Evaluation of small discontinuities
The echo heights are proportional to their area
or The echo heights are proportional to the
square of their diameter
Reflectors with different areas and their echoes
Reflectors at different depths and their echoes
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DAC(????????)
DAC(Distance Amplitude Correction Curve) ?? ???
??? ??? ?? ??? ??? ????? ??? ???? ?? ??? ??? ???
??? ??? ? ??? ?? ?? ?????? ????
DAC?? ??? Gain?? ???? ??? ?? echo??? gain ? ????
DAC??? ???? ? ??? gain ?(dB)?? ??.
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??? TEST
Detection of Reflectors ??? ??
Location of Reflectors ??? ?? ?? Calibration ?? ??
Evaluation of Reflectors ??? ?? ??
Diagonosis of Reflectors ??? ??

SCAN ??? A-SCAN ???
SCAN ??? B-SCAN ???
SCAN ??? C-SCAN 2?? ??
SCAN ??? D-SCAN 3?? ??
SCAN ??? E-SCAN ???
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???(dB)
V(dB) 20 log10 A (A?? , V A? ???? dB?)
dB?? ??? ??
0 dB 20 log10 A -------- A 1?
1 dB 20 log10 A -------- log10 A 0.05
-------- A 100.05 1.12 ?
2 dB 20 log10 A -------- log10 A 0.1
-------- A 100.1 1.26 ?
6 dB 20 log10 A -------- log10 A 0.3
-------- A 100.3 2 ?
14 dB 20 log10 A -------- log10 A 0.7
-------- A 100.7 5 ?
20 dB 20 log10 A -------- log10 A 1
-------- A 101 10 ?
40 dB 20 log10 A -------- log10 A 2
-------- A 102 100 ?