Seven Years of Uranium Alloy Development at Weldon Spring, 1959/1966. Page: 33 of 47
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
within the data for individual cores which was not reflected by the Mallinckrodt
data. Further study of this lack of agreement revealed that the technique used
at SRP was more selective, whereas the Weldon Spring procedure had a greater
tendency to show an average value of the growth index.82
To avoid the averaging effect from the scanning technique used at the Weldon'
Spring Laboratory, x-ray intensities for specific reflections were measured at
a number of different positions around the circumference of the core, holding
the core stationary for each of these measurements instead- of using the rotating
technique which had yielded the deceiving averages. Comparison of the
intensities measured- at these locations did reveal a wide variance supporting
the fact that the grain clusters were a real orientation effect and not an
artifact in metallography.28,83
In an effort to eliminate this variance, a revised beta quenching procedure was
tried in which the core blank after soaking at 1350*F. was plunged into a
second salt bath controlled in the range of 850-900 F. to achieve an, isothermal
transformation. This quench was particularly successful with an Fe-Si-Al-Cr
alloy originated by the French (Sicral F-2). Macrographs prepared from the
isothermally transformed material showed no evidence of grain clusters, and
stationary measurements of X-ray intensities around the periphery of the core
O.D. revealed that the variance previously observed had been reduced to a
minimum. Somewhat similar behavior was detected with an iron-silicon alloy
although the degree of variance observed in the perimeter of this sample was
greater than that associated-with the Sicral'F-2 composition. 'In this case,
however, the grain size was larger and may have contributed to the spread in
values determined. The response to this type of heat treatment suggested that
the optimum choice of secondary bath temperature and of alloy level:should be
such that the beta-to-alpha transformation would occur at the temperature of
the nose of the upper C-curve of the TTT diagram.1,2
Induction Heating Versus Grain Size
Beta heat treatment using induction heating had been proposed by the National
Lead Co. of Ohio staff at Fernald to permit an oil quench without the problem
of salt accumulation in the quenching bath that is unavoidable when using a
salt bath for preheat. Studies of the structure in induction heated cores had
revealed a shallow zone of very fine grain size at the O.D. of the core blank.
The suggestion was made at Weldon Spring that this zone of fine-grained
material was perhaps related to the depth of penetration of the heating current
induced by the high frequency field.58 If this had been the case, it might. be
argued that greater penetration of this heating current could provide a deeper
zone of fine-grained material. - It therefore seemed worthwhile to determine
whether a decrease in the frequency of the alternating field might lead to
sufficient penetration of the heating effect to achieve this very fine grain
:. . . ... .....
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Fellows, J. A. Seven Years of Uranium Alloy Development at Weldon Spring, 1959/1966., report, January 1, 1966; Weldon Spring, Missouri. (https://digital.library.unt.edu/ark:/67531/metadc1033773/m1/33/: accessed March 23, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.