TITLE:
Acoustic Emission Studies on Weld Bead Defects in Nuclear Grade SS 316L Materials
AUTHORS:
Ranganayakulu S. V., Shiva Raju J., Kuchedludu A., Ramesh Kumar B.
KEYWORDS:
Acoustic Emission Signatures, X-Ray Radiography, Lack of Side Fusion, Lack of Penetration, Tungsten Inert Gas Welding (TIG)
JOURNAL NAME:
Open Journal of Acoustics,
Vol.4 No.3,
August
21,
2014
ABSTRACT:
This paper contributes about the behaviour of Acoustic Emission (AE)
signatures of implanted weld defects of SS 316L materials. Lack of penetration
and lack of side fusion defects were implanted in weld bead region of the
materials. Tungsten Inert Gas Welding (TIG) is adopted to weld the Stainless
Steel (SS316L) nuclear grade materials. The material is fabricated with
dimensions of 140 × 16 × 10 mm and AE signatures are studied under preload
conditions. Mechanical Jig is fabricated to maintain constant load in
concentrated weld region. When external load is applied on the weld region, the
deformed specimen experiences acoustic emission signals form the weld defect
region which are potential source of releasing stress energy. Liner Location
Technique (LLT) is adopted for AE singal studies and the generated signal is
processed by 2-channel USB—AE node and AE-WIN software. The tests are conducted
on two different samples having each defect. A conventional NDT method i.e. X-ray Radiography is conducted on
the samples to know the defect ranging and correlated with AE signatures. This
study will be helpful to standardize the AE signals for different implanted
weld defects of SS 316L materials and it is found that, the parameter “counts
vs. amplitude” has given the widest distinction with respect to the type of
defects.