where expertise comes together - since 1996

Web's Largest Portal of Nondestructive Testing (NDT)
Open Access Database (Conference Proceedings, Articles, News), Exhibition, Forum, Network

All Forum Boards
Technical Discussions >
sound attenuation
Career Discussions
Job Offers
Job Seeks
Classified Ads
About NDT.net
Articles & News

VOGT Ultrasonics GmbH
non-destructive testing, services, training, ultrasonic systems, immersion and squirter inspection systems, PROline, digital radiology

402 views
01:49 Sep-16-2002
BÜLENT DOÐAN
sound attenuation

we cast a cylindrical shaped steel piece.inner redius is 20 ,outer redius is 60 cm. and height is 70 cm.when ý test the piece ultrasonically , ý realize a band in the middle zone of the test piece, where the sound attenuation occurs.why?


 
03:04 Sep-16-2002

Tom Nelligan

Engineering,
retired,
USA,
Joined Nov 1998
390
Re: sound attenuation : we cast a cylindrical shaped steel piece.inner redius is 20 ,outer redius is 60 cm. and height is 70 cm.when ý test the piece ultrasonically , ý realize a band in the middle zone of the test piece, where the sound attenuation occurs.why?


One likely explanation would be a significant change in grain structure or a concentration of microporosity in that region. Strictly speaking, both of these conditions affect ultrasonic scattering rather than attenuation, but I imagine that what you are seeing is a loss of backwall signal, and that could definitely be due to coarser grain or microporosity. You should try testing the part at a lower frequency.

--Tom Nelligan
GE Panametrics



 


© NDT.net - The Web's Largest Portal of Nondestructive Testing (NDT) ISSN 1435-4934

Open Access Database, |Conference Proceedings| |Articles| |News| |Exhibition| |Forum| |Professional Network|