Material characterization and numerical simulation … characterization and numerical simulation of...
Transcript of Material characterization and numerical simulation … characterization and numerical simulation of...
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