Content

Project approach

Unexpected challenges

Integration of phase results to realize draft ISO

Conclusions and recommendations

Draft ISO

2

Case for action

NDT method Method description Acceptance criteria

UT (PAUT) >6mm ISO 13588 ISO19285

PAUT thin wall 3.2-8.0mm ISO 20601 This project!

3

Phased Array (PAUT) gains popularity with advantages:

No radiation

Compliant with code requirements

Higher level of integrity (PoD critical flaws)

Direct result and feedback to welder possible

Less environmental impact

Digital storage of data

Case for action

4

Development acceptance criteria Phased Array on thin wall

welds (3.2-8.0mm)

Project basis:

Equal rejection rate as RT.

Acceptance criteria based on Good WorkmanShip.

Results generate basis for ISO standaard (ISO TC-44).

Project approach

5

Legenda: Experience

Checking

Theoretical part

Practical part

• Part D

• Field verification

• Part C

• Fracture Mech validation

• Part B

• Evaluation projects

• Part A

• Inventory literature

Part E

Concept Std.

Evaluation

Project highlights 22 participating companies

Steering group

Phase coordinators and quality coordinator

Specialist involvement

Budget: > € 600k

6

Project highlights Planning

7

Project phase Q3 2016 Q4 2016 Q1 2017 Q2 2017 Q3 2017 Q4 2017 Q1 2018 Q2 2018 Q3 2018 Q4 2018 Q1 2019

Project plan

A) Review of documentation available

B) Evaluation practical experiences

C) Fracture mechanical analysis

D) Practical testing

E) Evaluation

E) Implementation

Final report

Knowledge transfer

Administrative support

Project management

Project results Budget: No overrun

Planning: initial planning is delayed by 16 months

Quality: high quality research with significant amount of specialists

involved

Output: Draft ISO

Phase EGoal:

- Combine results of other phases into practical acceptance criteria

- Create draft ISO document

- Submit draft ISO document via NEN

Later:

Discuss draft in ISO/TC 44/SC 5/WG 2 “Ultrasonic testing of welds“

- March 31st and April 1st, 2020, NEN, Delft

9

Phase E- Combine results of other phases:

- Phase A literature study

- Phase B evaluation of previous PA testing

- Reliability study

- Phase C fracture mechanical analysis

- Phase D comparison to RT

- Good workmanship approach (not FFP)

- Practical, easy to interpret acceptance criteria

10

Phase ECreate draft ISO document in line with:

- Structure in other ISO documents

- ISO 17635 Non-destructive testing of welds – General rules for

metallic materials

- ISO 5817 Welding – Fusion-welded joints in steel, … – Quality

levels for imperfections

- ISO terminology

11

Phase EConsiderations and observations:

- ‘Translate’ project results

- Definition of threshold level, evaluation level

- % FSH → dB reference level

- Define Acceptance criteria (not rejection criteria)

- Only amplitude and indication length, not height

- Length only measured by -6 dB method

- No characterisation of indications

- No split in thickness range 3.2 – 8.0 mm

12

Phase ERequired levels for the ISO standard:

- Reference level

- Acceptance level

Optionally in the ISO standard:

- Reporting level

- Evaluation level

- Registration/recording level

Definitions of terminology are given in ISO 5577

13

Phase EResults from phase D comparison to RT:

Acceptance level 1 (stringent)

- Amplitude ≤ Reference level +2 dB (100 % FSH) AND indication

length ≤ 6 mm

- Amplitude ≤ Reference level -6 dB (40 % FSH)

- Indication length ≤ 4 mm

- Reference level = 1 mm SDH (at 80 % FSH)

- Amplitude ≤ Reference level -12 dB (20 % FSH) not recorded

14

Phase EAcceptance level 1 (stringent) from phase D:

15

Amplitude[dB]

0

Indication length [mm]

+2

-12

4 6

Ref.level

-6

+6

Phase EResults from phase C:

Acceptance level 1 (stringent)

- Indication length ≤ 6 mm

- Amplitude ≤ Reference level -12 dB (20 % FSH)

- This is lower than in phase D

16

Phase EAcceptance level 1 (stringent) from phase C:

17

Amplitude[dB]

0

Indication length [mm]

+2

-12

4 6

Ref.level

-6

+6

Phase EAcceptance level 1 for draft ISO:

18

Amplitude[dB]

0

Indication length [mm]

+2

-12

4 6

Ref.level

-6

+6

Indications <4 mm with very high amplitude are not allowed

Ref -10 dB

Evaluation level

Phase EAcceptance level 2 for draft ISO:

19

Amplitude[dB]

0

Indication length [mm]

+3.5

-12

4 7

Ref.level

-6

+6

Ref +3.5 dB

Ref -10 dB

Evaluation level

Phase EAcceptance level 3 for draft ISO:

20

Amplitude[dB]

0

Indication length [mm]

+5

-12

4 8

Ref.level

-6

+6

Ref +5 dB

Ref -10 dB

Evaluation level

Phase EAcceptance levels for draft ISO, double sided PA:

21

Amplitude[dB]

0

Indication length [mm]

+5

-12

4 8

Ref.level

-6

+6

3

Ref -10 dB

21

+2

6 7

Evaluation level

Phase E- Grouping of indications is not applicable.

- Cumulative length:

- The cumulative length of all individually acceptable indications above

evaluation level is calculated within a specified section of weld length, lw, as

the sum of lengths of both single indications and linearly aligned indications

22

Phase ECumulative length:

For wall thickness T, the sum of the lengths of the individual indications measured along the weld over a length of 12 T shall be ≤:

for acceptance level 1: 3,5 T,

for acceptance level 2: 4,0 T ,

for acceptance level 3: 4,5 T .

23

Phase ESingle sided testing:

- Lower POD compared to double sided PA

- Lower amplitudes

- Information from phase B into D

24

Phase EResults from phase B/D comparison to RT:

Acceptance level 1 (stringent) single sided PA

- up to 4mm length: 6 dB evaluation level for double sided, no

evaluation level for single sided testing

- Amplitude comparable to double sided testing, but indication length

is 2.5, 4 or 5.5mm instead of 6, 7 or 8 mm length for double sided

testing.

25

Phase EAcceptance level 1 for draft ISO, single sided:

Amplitude[dB]

0

Indication length [mm]

-12

2.5

Ref.level

-6

+6Acceptance level 1

Evaluation level-10

+2

Phase EAcceptance level 2 for draft ISO, single sided:

Amplitude[dB]

0

Indication length [mm]

-12

Ref.level

-6

+6Acceptance level 2

Evaluation level-10

4

+3.5

Phase EAcceptance level 3 for draft ISO, single sided:

Amplitude[dB]

0

Indication length [mm]

-12

5.5

Ref.level

-6

+6

Acceptance level 3

Evaluation level-10

+5

Phase ENext steps:

- Required changes to draft?

- Submit draft ISO document via NEN

29

Thank you!

Phase E project team – Erik, Adri, Casper, Jan Willem, Norbert, Ben,

Rene, Leo. Special thanks to Erik and Adri.

Project leads – Erik, Adri and Leo

Integration phase results

Phase D: Tuning effects of acceptance criteria

Integration phase results

Phase D: Acceptance criteria PAUT double sided

Conclusions/recommendations Rejection rate of PAUT per weld length is higher than RT.

RR of PAUT per number of welds is comparable to RT.

Learning effect of NDT operator and welder will result in significant

improved PAUT performance.