Sz. Szávai1, Z. Bézi1, Judit Dudra1, P. Rózsahegyi 2

Material characterization and numerical

simulation of a dissimilar metal weld to

support phased array ultrasonic

inspection

1 Engineering Division (BAY-ENG)

Department of Structural Integrity and Production Technologies2 Engineering Division (BAY-ENG)

Department of Material Testing, Mechanical Testing Laboratory

Lyon, 23-27. 10. 2017

PLIM

Typical DMW defects• Hot tearing (solidification), Cold cracking (residual stress), Blowholes,

voids, gas inclusions. Corrosion or fatigue cracks

• These welds usually have damages in the HAZ of ferritic steels or in the buttering, where material discontinuity cannot be recognised in all cases.

• Intergranular corrosion attack starting from the internal surface

• Discontinuities can be found on pipe circumference

Problem with inspection

• Because of traditional geometrical settings, location of anomalies and

their size cannot always be measured.

• There are so many welds, what are only can be reached very difficultly

by conventional ultrasonic testing because of the geometry of the

welds or the equipment, and just can be inspected completely by

multiple tests.

• Because of great variety and special design of welded

structures, several test blocks (“mock-up”) would be needed to

be manufactured for inspection preparation and validation.

Problem with inspection

• Phased array ultrasonic testing techniques gives

the chance to determine more accurate

parameters during the preparation of inspection,

and reach better probability of detection (POD).

PAUT for DMW’s inspection

PAUT for DMW’s inspection

• Up-to-date simulation software can be capable to verify detection of

different anomalies in the case of different welds and materials.

• Model and validate phased array ultrasonic testing (PAUT) techniques

for NDE of DMW.

• Results from characterization will serve as an input for modelling and

simulation of PAUT on DMW.

• The results of simulation will be compared with the inspection results.

Dissimilar metal welds

Disadvantages of UT:

• Textured polycrystalline materials

• Heterogeneous and anisotropic material properties

o Ray scattering és refraction

o Anisotropic attenuation

(grain size, macrograph)

Isotropic

Ray path

planning

Anisotropic Anisotropic (material attenuation)

Phased array beam

Dissimilar metal weld

Defect detection:

Isotropic material:

• Ray path can be calculated

Anisotropic material:

• Ray path?:o Variable elastic modulus?

o variable grain size – attenuation?

Interfacial ray reflection and transmission