On the assessment of macro inclusions in stainless steels using ultrasonic technique.
2004 (English)Conference paper (Other academic)
Determination of the inclusion size distribution in clean steels is a difficult task since the inclusion content is very low. This is even more pronounced for inclusions in the size range between 20-100 microns. Depending on the steel application the inclusions might cause fatigue failure or rupture. The use of light optical methods for the assessment of macro or semi macro inclusions in such steel grades is not beneficial since finding sufficient number of inclusions for statistical calculations, is a very time consuming process. The application of ultrasonics with immersed scanning high frequency transducers has proven to be an excellent tool for this purpose. This technique is now used as a standard tool by a producer of ball bearing steels. However, for stainless steels there are limitations of the ultrasonic technique. In this study examination of different stainless steel grades has been done and it clearly shows that the austenitic crystal structure attenuates the sound wave to such an extent that the inclusions detected are hidden behind the background noise. This is more or less independent of the grain size. The overall result is that Ultrasonic examination for the assessment of macro and semi macro inclusions is a reasonable method for stainless steel grades with other structure than austenitic.
Place, publisher, year, edition, pages
Other Engineering and Technologies not elsewhere specified
IdentifiersURN: urn:nbn:se:kth:diva-26951OAI: oai:DiVA.org:kth-26951DiVA: diva2:373135
The 16th World Conference on Nondestructive Testing, Montreal, Canada, August 30-September 3, 2004
QC 201011302010-11-302010-11-302010-11-30Bibliographically approved