Static strain-aging in nickel 200 between 373 and 473 K

Journal Article · Sat Jan 01 04:00:00 EST 1977 · Metall. Trans., A; (United States)

DOI:https://doi.org/10.1007/BF02677266· OSTI ID:6168249

Cribb, W R ^[1]; Reed-Hill, R E

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1. Republic Steel Corp. Research Center, Cleveland, OH

Static strain aging was investigated in Nickel 200 using tensile specimens aged between 373 and 473 K. The kinetics of the lower yield stress return may be described in terms of either a t/sup 1/7/ or a log t relationship. The activation energy for the process was about 25,000 cal/mole. It is believed, as proposed by Rose and Glover and by Jenkins and Smith for austentic stainless steels, that the aging phenomena are associated th carbon atom vacancy pairs which undergo Snoek ordering in the stress fields of dislocations. Macroscopic hardening probably results from the growth of atmospheres of pairs around the dislocations as a result of the drift of vacancies toward the dislocations. However, the growth of these atmospheres should be a slow process because the trapping of vacancies by the much less mobile carbon atoms seriously limits the number of free or mobile vacancies. Finally, since the number of vacancies which were formed by the prestrain deformation greatly exceeds the thermal equilibrium concentration of vacancies, there should be a slow loss of vacancies to sinks. This can explain the fact that at long times pronounced overaging is exhibited.

• OSTI ID: 6168249
• Journal Information: Metall. Trans., A; (United States), Journal Name: Metall. Trans., A; (United States) Vol. 8:1; ISSN MTTAB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ACTIVATION ENERGY
AGING
ANNEALING
ELEMENTS
ENERGY
HEAT TREATMENTS
HIGH TEMPERATURE
MECHANICAL PROPERTIES
METALS
NICKEL
STRAIN AGING
TENSILE PROPERTIES
TRANSITION ELEMENTS