Stress measurement Fastress

The Fastress instrument is not a diffractometer but rather a stress gauge that must be calibrated with specimens containing known stresses. It is specifically designed for measurements on ferritic and martensitic steels (BCC) by observation of the 211 reflection with CrKoc radiation at a 26 angle of about 156°. Counter movements are restricted to a range of 152° to 159°, and only materials that produce... 

Fig. 16-13 Fastress stress analyzer. Close-up of x-ray tubes and counters. The table supporting the specimen shown here is removable, so that stress may be measured in much larger objects. (Courtesy of American Analytical Corporation.)...

The small diameter of the incident beam from a stress camera or a Fastress unit is an advantage when one wishes to measure stress variations from point to point on a surface, as in the region near a weld. The stress distribution shown in Fig. 16-16, determined by a photographic method, simulates the residual stresses due to spot welding. The specimen was a steel strip 10 x 3 x inch (25 x 8 x 0.6 cm). A circular area of about I inch (1 cm) diameter, whose size is indicated on the graph, was heated locally to about 700°C for a few seconds by clamping the strip at its center between the two electrodes... 

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See also in sourсe #XX -- [ ]

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