Anomalous hardening in model alloys and steels thermally aged at 290 C and 350 C: Implications to low flux irradiation embrittlement

Conference · Fri Oct 01 04:00:00 EDT 1999

OSTI ID:679481

Odette, G R; Lucas, G E; Klingensmith, D ^[1]

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1. Univ. of California, Santa Barbara, CA (United States). Dept. of Mechanical and Environmental Engineering

Age hardening at 290 C and 350 C in five simple ferritic alloys with systematic variations in Cu and Mn and four A533B-type split melt steels with systematic variations in Cu and Ni was evaluated for times up to 7200h. Significant yield stress increases were found in alloys containing high copper and nickel. The hardening is consistent with formation of copper-rich precipitates. However, the precipitation kinetics are accelerated relative to estimates based on extrapolations of the high temperature copper diffusion coefficient. Further the observed high sensitivity to both copper and nickel content is not understood. The rapid thermal kinetics suggest that embrittlement due to age hardening could occur in sensitive pressure vessel steels during extended service. Further, high thermal diffusion rates must be considered in models of the effect of flux on hardening and embrittlement. Anomalously high diffusion would also introduce a new rate-dependent regime at very low fluxes. Hence, the peak irradiation hardening from copper-rich precipitates may occur at much lower fluences than predicted by current data correlations.

• OSTI ID: 679481
• Report Number(s): CONF-960643--
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
36 MATERIALS SCIENCE
AGE HARDENING
CHEMICAL COMPOSITION
EMBRITTLEMENT
FERRITIC STEELS
MICROSTRUCTURE
PHYSICAL RADIATION EFFECTS
PRESSURE VESSELS
REACTOR MATERIALS
STEEL-ASTM-A533-B