Upper nose temper embrittlement of a Ni-Cr steelJaffe, L. D.;Buffum, D. C.
doi: 10.1007/BF03398437pmid: N/A
Abstract Temper embrittlement of a Ni-Cr steel was investigated both isothermally and with temperature changes. Embrittlement was most rapid in two temperature ranges: 490° to 550°C and just below the Ae1, near 675°C. Embrittlement in the lower range was accompanied by rapid grain boundary attack by ethereal picric acid and fracture along austenite grain boundaries. Embrittlement in the upper range was accompanied by slow attack by ethereal picric acid and fracture mostly along ferrite grain boundaries. No increase in ferrite grain size was observed, but carbide particles grew during treatments in the upper temperature range. Embrittlement during slow cooling from 675°C appeared to be associated with the lower range.
On the nature of embrittlement occurring while tempering a Ni-Cr alloy steelBhat, G.;Libsch, J. F.
doi: 10.1007/BF03398439pmid: N/A
Abstract Data are presented to show that embrittlement in a Ni-Cr alloy steel proceeds by one mechanism at 925°F and by a different mechanism at 1250°F. The embrittlement occurring at 925°F may be removed completely by reheating to higher temperatures for very short times and has no influence upon further embrittlement at 1250°F. The embrittlement occurring at 1250°F appears related to a permanent structural change which has a significant retarding influence upon subsequent development of embrittlement at 925°F. It is suggested that retrogression phenomena are not necessary to explain embrittlement; on the other hand, segregation of solute atoms to prior austenite and ferrite grain boundaries may provide a better explanation of the occurrence of the two modes of embrittlement.
Uranium-silicon alloysKaufmann, A.;Cullity, B.;Bitsianes, G.
doi: 10.1007/BF03398440pmid: N/A
Abstract A tentative U-Si phase diagram was determined by the present authors about 10 years ago. A description of the experimental work has not been published in the open literature, although the resulting phase diagram did appear in the National Nuclear Energy Series.1 In 1949 Zachariasen2 published crystal structure determinations for the U-Si intermetallic compounds and came to the conclusion that several of the formulas assigned to the compounds by Kaufmann et al. were in error. The purpose of the present paper is to describe the original work done in 1944 and, in particular, to discuss some of the properties of one of the intermediate phases, known as ϵ, whose formula is approximately U3Si.
Investigation of the effects of solutes on the grain boundary stress relaxation phenomenonWeinig, S.;Machlin, E. S.
doi: 10.1007/BF03398443pmid: N/A
Abstract An experimental investigation of grain boundary stress relaxation in copper binary alloys with nickel, silicon, aluminum, and silver comprising the range 0.03 to 1 atomic pct solute has been carried out. Two stress relaxation peaks of grain boundary origin have been ascertained and studied. The energy of activation and peak temperature for both peaks have been determined as functions of solute content and type of solute. It is suggested that this technique can be used as a measure of adsorbability of solute at grain boundaries as a consequence of the saturation effects observed in the measured properties in the vicinity of 0.1 atomic pct solute.