FIFTH CANADIAN CONFERENCE ON NONDESTRUCTIVE ... - IAEA

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It incorporates many of the features of the commercial prototype
although it lacks the w-rotation. Relative accuracies of ±18-20 MPa
(standard deviation) have been obtained on annealed ferritic steel and
cold worked Inconel 600 calibration beams, for example Fig. 9. The
counting times used to obtain this accuracy are ~150s with another 90s
in executing the o-motion of the X-ray tube. With streamlining of the
software and improvements in data reduction measurement, times for fine
grained ferritic steels will be further reduced (possibly by a factor of
2).
In actual applications, the engineering version of the diffractometer
gives results comparable with those obtained using a standard
Phillips X-ray diffractometer modified for stress measurement (8), for
example Fig. 10.
SUMMARY
The CANMET Protable Stress Diffractometer is designed for field
and laboratory use. The design takes advantage of the error compensating
feature of the single exposure technique, but still allows the investigation
of stress distributions requiring multiple exposures. New detector
and solid state electronics technologies have been applied to make
it transportable for field use under clement conditions. It will be as
accurate as standard laboratory equipment and have sufficient versatility
for dedicated laboratory applications. A unique feature (the a-drive)
allows the elimination of texture gradient and coarse grain size effects.
A commercial prototype incorporating these features is currently under
construction.
ACKNOWLEDGEMENTS
The CANMET Portable X-Ray Stress Diffractometer was conceived,
and until his retirement January 198 1 !, developed, by CM. Mitchell of the
Physical Metallurgy Research Laboratories (PMRL), CANMET, Department of
Energy, Mines and Resources Canada. The engineering model of the instrument
was designed and made by Proto Manufacturing Ltd., Oldcastle,
Ontario, in 1983 with funding from CANMET. The commercial prototype of
the diffractometer will be made by the same company within the framework
of the Program for Industry Laboratory Projects (PILP). We wish to thank
J.A. Hunter of NRC for his enthusiastic support in the role of PILP
Project Manager and D.W.G. White of PMRL for useful discussions and help
in other ways.