Acoustic emission (AE) signals from weld defects, incomplete penetration (IP), slag inclusion (SI), and porosity (PR), in longitudinal seam welding of UOE steel pipes were evaluated by using an envelope analysis system and waveform analysis system. In test results, the location accuracy of the envelope and the waveform systems during the loading tests were a few 10 mm and a few mm, respectively. AE activity and intensity and waveform type could identify the welding defect types. Three types of AE spherical radiation patterns (AERPs), a monopole mode, a tensile fracture of dipole mode, and a tensile and shear mixed of dipole mode, were observed during the test. Information from cross section observation of the IP by SEM and AERP suggested that activity and intensity of AE signals from welding defects could depend on both stress concentration of the defect and brittleness of the microstructure around the defect.

Issue Section:
Research Papers
Topics:
Acoustic emissions, Steel, Waveform analysis, Welding, Dipoles (Electromagnetism), Signals, Brittleness, Fracture (Materials), Pipes, Porosity, Radiation (Physics), Shear (Mechanics), Slags, Stress concentration
1.
Fowler, T. J., 1984, “Acoustic Emission Testing of Chemical Process Industry Vessels,” Progress in Acoustic Emission II, M. Onoe et al., eds., JSNID, Tokyo, Japan, pp. 421–449.
2.
Kishi
T.
, and
Ohira
T.
,
1984
, “
Evaluation of Fracture Mode by Radiation Pattern in Acoustic Emission Signals
,”
Journal of Japan Institute of Metals
, Vol.
48
, No.
9
, pp.
911
–
917
.
3.
Scruby
C. B.
, and
Stacey
K. A.
,
1988
, “
Acoustic Emission Measurements on PWR Weld Material with Inserted Defects
,”
Journal of Acoustic Emission
, Vol.
7
, No.
2
, pp.
81
–
93
.
4.
Shiwa, M., Kishi, T., Mitsuno, S., and Ichikawa, H., 1993, “Fracture Analysis of SiC/SiC Composite by Using In-plane Spherical Radiation Pattern,” Proceedings, 3rd Japan International SAMPE Symposium, T. Kishi, et al., eds., SAMPE, Chiba, Japan, pp. 2377–2382.
5.
You, T., Lee, M., Shiwa, T., Kishi, T., et al., 1995, “Fracture Mechanism Analysis of SiC/SiC Composites in ILSS Test by AE Spherical Radiation Pattern Method,” Proceedings, AECM-5, ASNT, Sundsvall, pp. 233–239.
6.
Aki, K., and Richards, P. G., 1980, Quantitative Seismology: Theory and Methods, Vol. I. W. H. Freeman and Company, San Francisco, CA.
7.
Kuribayashi, K., and Kishi, T., 1982, “Application of Radiation Pattern of Acoustic Mission in Determination of Elastic-Plastic Fracture Toughness,” Progress in Acoustic Emission, M. Onoe et al., eds., JSNDI, Susono, pp. 295–302.
8.
Shiwa
M.
,
Inaba
H.
,
Carpenter
S. H.
, and
Kishi
T.
,
1992
, “
Development of High-Sensitivity and Low-Noise Integrated Acoustic Emission Sensor
,”
Materials Evaluation
, Vol.
50
, No.
7
, pp.
868
–
874
.
9.
Mashino, S., Shiwa, M., and Kishi, T., 1990, “Development of Dynamic Crack Microscope—Multi-Channel AE Signal Processing System,” Progress in Acoustic Emission, V. K. Yamaguchi et al., eds., JSNDI, Sendai, Japan, pp. 387–393.
10.
Fleischmann, P., and Rouby, D., 1984, “Burst Type and Continuous Acoustic Emission Signal Analysis in A Broadband Frequency Range Leading to Source Characterization,” Progress in Acoustic Emission II, M. Onoe et al., eds., JSNID, Zao, pp. 114–124.
11.
Enoki
M.
, and
Kishi
T.
,
1988
, “
Theory and Analysis of Deformation Moment Tensor due to Microcracking
,”
International Journal of Fracture
, Vol.
38
, pp.
295
–
310
.
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