Table of Contents - PACNDT 98
By Rolf Diederichs
Rolf Diederichs attended some lectures during this conference; see summaries below. (Obviously, he couldn't attend all 50 conference presentations). These lecture summaries do not constitute endorsement of products or services mentioned, and opinions and views expressed in the lectures are those of the presenters.
Making NDT Part of the Process|
Dr. Jean F. Bussiere (email@example.com), Director Industrial Materials Institute National Research Council of Canada.
NDT, as applied to manufacturing, is mostly used to inspect the quality of
parts at the end of the process. This can often result in high costs.
Instead of focusing on the quality of parts, it is better to focus on the
process, to prevent rejection of parts, thus increasing savings.
Typical applications are found in the Aluminum and Glass industries, for
both use thickness measurement applied with NDT sensors. The steel
industry concentrates on controlling the temperature, chemistry,
and material behavior, as well as mechanical properties. The sensors
effective, non invasive, robust, reliable and must be inexpensive.
Ultrasonics are applied to measure the grain size profile of steel by sound
attenuation; this was applied as real time monitoring of grain size growth
during heat treatment. Laser ultrasonics can be used for flaw detection in
a very early stage on the hot product. Thermal spray coating process control
was another application that Dr. Bussiere introduced.
Application of Ultrasonic Testing Methods for Volumetric and Surface lnspection of CANDU Pressure Tubes.
Mr. Trelinski introduced an Ultrasonic system "CIGAR", a pressure tube
inspection system which has been used successfully over the last twelve
years. It has
proven to be a reliable, accurate tool for detection,
characterization and sizing. The sizing technique is based on a crack
depth measurement by evaluation of the pulse arrival time of crack tip and
bottom. The results of a 0.6 mm notch were demonstrated.
In the discussion he made clear that in 95% of cases only the impulse echo
signal is used as opposed to the diffracted signals which are to mostly too
weak. Mr. Trelinski showed some impressive colorful B-scan images, which
are nice but not very useful.
Mechanized Ultrasonic Inspection of Large Diameter Gas Pipeline Girth Welds
There has been a great deal of discussion on the pros and cons of TOFD in
This presentation offered some background on the application of mechanized
pipeline construction and went on to demonstrate how TOFD is not an
effective stand-alone UT technique for this application but acts as an
effective safety net for some critical defects. During the discussion Mr
Moles explained that today ultrasonics are better than X-ray.
The Engine Titanium Consortium Goals, Achievements and Future Plans
K. Smith - Pratt and Whitney Florida ; L. Bruscha - IOWA State University Contact: L.Brasche email: firstname.lastname@example.org
Lisa Bransche, Associate Director of the CNDE at Iowa State University, is
the program manager of the FAA Center for Aviation System Reliability, and
facilitator for the Engine Titanium Consortium whose work has been
received a grant. The program was initialized due to the disaster of
United Flight 232 in 1989 which resulted in the loss of 111 lives. The
National Transportation Safety board concluded that a titanium defect, known
as "hard alpha" was involved in the accident. Efforts are underway to
provide implications for detectability. POD estimates for billet and
forgings will be provided at the close of the program.
NDTnet provided more information about this in the ASNT Pittsburgh Fall
1997 Report. During the
conference we invited Lisa Bransche to submit an e-file of the proceedings
and/or permission to use for NDTnet. Her answer was "Not Possible due our
Question: Is this the best way for publicly funded work to make their
results available? Especially if the information contained could save
lives? It was noted that conference publishers got the material so perhaps
this "no use" policy applies only to
Remote Visual Testing (Rvt) For Internal Pressure Vessel Inspection
Bruce A. Pellegrino, R.Linder, Visual Inspection Technologies, Inc., email: email@example.com
Bruce A. Pellegrino presented a paper which has already been published in
No. 8. AUGUST 1998.
The article details a video inspection camera system which has been
successfully used to inspect several hundred vessels to date. Users report
savings between U.S. $5,000 - $50,000 per deployment by not having to shut
down or send personnel into these vessels. Additionally, a faster, safer,
more thorough and better documented inspection is achieved. The video
been digitized and transmitted over the INTERNET to corporate engineering
headquarters for analysis, archiving and trending.
Review of IAR NDI Research in Support of Aging Aircraft
A.Fahr, D.S. Forsyth, D.W. Schindel, ; C.E. Chapman - Institute for Aerospace Research, National Research Council Canada Contact: A.Fahr email: ABBAS.FAHR@NRC.CA
Fatigue cracks and corrosion are the main aging aircraft concerns,
said David Forsyth from IAR.
Developments of ultrasonic guided waves have been carried out in close
collaboration with Tektrend.
Air-coupled ultrasonic testing also showed encouraging results. Surface
waves have been used for detection of cracks under fasteners. He introduced
the Edge of Light method which has been recently developed and patented at
NRC. Digital X-Ray is applied for the inspection of thickness losses at IAR.
An official approval of the guided wave method will be take a while, but
until then it might be applied as an informal inspection method, Forsyth
Laser Ultrasonics for Inspection and Characterization of Aeronautic Materials.
This presentation was made by Jean-Pierre Monchalin, the so-called father of laser ultrasonics. He also presented this paper at the ECNDT'1998 in Copenhagen. Laser-Ultrasonics in brief: Advantages: Non-contact and at a distance (application to high temperature) Complex shapes Small spot or large spot probing Efficient generation of surface waves and plate waves No water Drawbacks: The emitting transducer is the material Sensitivity less than piezoelectric (at detection), but solved to the point it is usually adequate Cost (depends on application)
- Jean-Pierre Monchalin also made another presentation on behalf of C.K.
"Novel Clad Ultrasonic Buffer Rods for the Monitoring of Industrial
Rolf Diederichs started a spirited discussion; (earlier we mentioned
Rolf's experience in the area of process control, back in his pre-Internet
days). Measurement with probes in dies is possible, years ago Rolf did the
together with manufacturer and machine makers. But
what was the result? Again the main problems we mentioned above.
No machine maker like Krupp Kautex or Battenfeld Fisher has followed such
idealistic ideas for years; selling machines is their main business, not
causing price increases by adding NDT elements, whether such additions are
needed or not.
An Enhanced Florescent Liquid Penetrant Inspection Technique for Measurement of Surface Cracks
M. Yanishevsky - Department of National Defense Contact: M. Yanishevsky email: firstname.lastname@example.org
In his presentation, Marko Yanishevsky made effective use of the unusually long 45 min allotted to each speaker. Videos showed attendees the visibility of enhanced LPI. With the tensile test load it is possible to overcome the compressive residual stresses to open up these cracks. Cracks with surface length of 0.3 mm could be reliably measured using this technique.