The Influence of PAUT Parameters on Crack Location, Pattern and

JUNE 2010

CIORAU-PAUT PARAMETERS 1

3RD INT CANDU IN-SERVICE-INSPECTION & NDT IN CANADA 2010 CONFERENCE

The Influence of PAUT Parameters on

Crack Location, Pattern and Height Sizing

Peter Ciorau – Ontario Power Generation

Inspection, Maintenance & Commercial

Services Division - Pickering – Canada

E-MAIL : [email protected]

JUNE 2010



OUTLINES:

1. PROBLEM STATEMENT

2. EXPERIMENTAL PROGRAM

3. WEDGE AND PROBE PARAMETERS

4. MACHINE + FOCAL LAW PARAMETERS

5. CONCLUSIONS

6. ACKNOWLEDGEMENTS

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• DEFECT PARAMETERS (LOCATION, LENGTH, HEIGHT,

PATTERN (NATURE) MAY BE INFLUENCED BY:

- PROBE (DEAD ELEMENTS, PITCH SIZE, ACTIVE

APERTURE)

- WEDGE (ANGLE, VELOCITY, H1)

- TESTPIECE VELOCITY

- MACHINE (FILTERS, FREQUENCY)

- FOCAL LAW CALCULATOR (FOCAL DEPTH,

ACTIVE APERTURE, ANGULAR RESOLUTION)

• TOLERANCES MUST BE SET BASED ON APPLICATION

(WHAT IS CRITICAL FOR FINAL REPORTING)

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• PAUT IS NOT DIFFERENT FROM CONVENTIONAL UT

• ERRORS MUST BE QUANTIFIED

• THERE ARE LIMITS AND “TRICKS” IN PAUT

• ONE MUST EXPECT THE ACCURACY IN SIZING, LOCATION

AND DISPLAY (PATTERN) MAY BE AFFECTED BY SYSTEMATIC,

RANDOM AND HUMAN ERRORS

• CAN PAUT COMPETE WITH TOFD (+/- 0.3 MM) ?

• CAN PAUT PERFORMANCE BE IMPROVED BY ACCESS AND

SPECIAL SET-UPS?

• CAN WE AFFORD CUMULATIVE INDEPENDENT ERRORS?

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TEST # BLOCK ID PROBE ID FEATURES

1OHR 20

# 18

TW : P66-45T

(PLEXIGLASS)CRACK HEIGHT (D), LOCATION

2 AB 259TW : P9-30REX

(REXOLITE)

CRACK HEIGHT (D) LOCATION,

PATTERN

3 AB 163B LW : 78, 80, 84CRACK HEIGHT (S)

LOCATION, ANGLE

4L-1 ST.

AS BUILTLW : P21, P25

CRACK LENGTH (D)

LOCATION, ANGLE

5OHR 20

ACUREN-SCCTW : P74-45T CRACK HEIGHT, PATTERN

JUNE 2010




• EVALUATE INDIVIDUAL TOLERANCES TO GET:

- ± 1 mm crack height accuracy

- ± 1 mm crack ID location

- ± 2 mm for index (projected distance)

- ± 2 for sizing / detection angle

• ESTIMATE TOLERANCES FOR COMBINATION OF FACTORS

• SET REALISTIC TOLERANCES FOR DIFFRACTED INSPECTIONS

(SIDE TECHNIQUE ON L-1 STEEPLE)

• EVALUATE THE S-SCAN DISPLAY FOR WEDGE, PROBE AND

TESTPIECE VARIABLES (VELOCITY, ANGLE, HEIGHT, PITCH)

JUNE 2010




WHY SUCH TOLERANCES ?

- TURBINE INSPECTION (LITTLE MARGIN OF ERRORS; COMPARISON WITH MP

AND FM )

- SCC PATTERN – A MUST (HIGH RESOLUTION)

4.2 mm

15.8 mm

JUNE 2010




WHY SUCH TOLERANCES ?

- TURBINE INSPECTION (LITTLE MARGIN OF ERRORS)

- SCC PATTERN – A MUST (HIGH RESOLUTION)

HIGH

RELIABILITY

PAUT

RESULTS VS

MP AND FM

STEEPLE / BLADE

GEOMETRY

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TEST #1

LOCATION

PLEXIGLASSHEIGHT

WEDGE VELOCITY

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REXOLITE WEDGE VELOCITYTEST #2

2450 m/s2250 m/s

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3. WEDGE AND PROBE PARAMETERSWEDGE ANGLETEST #2

28 DEG30 DEG

ACTUAL33 DEG

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3. WEDGE AND PROBE PARAMETERSHEIGHT OF THE 1ST ELEMENT

1.5 mm 3.5 mm

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3. WEDGE AND PROBE PARAMETERSCAN WE ACCEPT THESE TOLERANCE – COMBINED?

TEST #2

H1 = 3.5 MM; 2300 M/S; 32 DEGREES H1 = 1.5 MM; 2400 M/S; 28 DEGREES

NOT ACCEPTED !

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3. WEDGE AND PROBE PARAMETERSPROBE PITCHTEST #1

Tolerance: +/- 50 microns

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3. WEDGE AND PROBE PARAMETERSPROBE PITCHTEST #2, 3

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P 25 – 0.8 MM

P 25 – 0.6 MM

P 25 – 0.4 MM

ACTUAL

TOLERANCE: + / - 150 MICRONS

JUNE 2010




VIDEO DISPLAY

SMOOTHING ON SMOOTHING OFF

JUNE 2010




ANGULAR

RESOLUTION

10 A-SCANS

COURTESY OLYMPUSNDT-USA

ELECTRONIC

/LINEAR SCANNING

0.5 DEG 1 DEG 4 DEG

JUNE 2010




FILTERS AND FOCAL DEPTH

TEST #5

F = 7 MM; 10 MHZ

F = 4 MM; HR 10 MHZ

F = 2 MM; HR 10 MHZ

F = 1 MM; HR 10 MHZ

SCC DEPTH,

PATTERN

JUNE 2010



4A. TESTPIECE VELOCITY PARAMETERS

3050 M/S3200 M/S 3350 M/S

TOLERANCE:

+/- 100 M/S

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5. CONCLUSIONS

• TOLERANCES MUST BE SET FOR SPECIFIC APPLICATIONS

• INDIVIDUAL TOLERANCES ARE LARGER THAN THE COMBINED

ONES

• 1ST HEIGHT : NO EFFECT ON CRACK HEIGHT AND PATTERN;

EFFECT ON LOCATION; +/- 1 MM ACCEPTABLE

• WEDGE VELOCITY: + / - 60-80 M/S ACCEPTABLE

• WEDGE ANGLE: + / - 1 DEGREE ACCEPATABLE

• PROBE PITCH: + / - 60 MICRONS ACCEPTABLE

• TESTPIECE VELOCITY: + / - 80 M/S ACCEPTABLE

• OTHER PARAMETERS, SUCH AS FILTERS, FOCAL DEPTH AND

ANGULAR RESOLUTION MUST BE SET BASED ON APPLICATION;

BETTER TO COVER 0.2-1.2 T; < 0.5 DEGREES; RECOMMENDED HR

FILTERS

JUNE 2010



6.0 ACKNOWLEDGEMENTS

1. The author thanks to the Management of IM&CS

Division - OPG for granting the presentation and

publication of the present paper to the 3-rd CANDU

ISI & NDT in Canada-2010 Conference.

2. Special thanks to Chris Chartier - Acuren Oakville

for welded pipe sample with SCC.

3. Thanks to OlympusNDT – Waltham – USA for

allowing to use 2 figures from PA book.

QUESTIONS ?THANK YOU !

Documents

The Influence of PAUT Parameters on Crack Location, Pattern and