SYMPOSIA PAPER Published: 01 January 1999

Anomalous Hardening in Model Alloys and Steels Thermally Aged at 290°C and 350°C: Implications to Low Flux Irradiation Embrittlement


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.

Author Information

Odette, GR
University of California, Santa Barbara, Santa Barbara, CA
Lucas, GE
University of California, Santa Barbara, Santa Barbara, CA
Klingensmith, D
University of California, Santa Barbara, Santa Barbara, CA
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E10
Pages: 88–101
DOI: 10.1520/STP13859S
ISBN-EB: 978-0-8031-5395-0
ISBN-13: 978-0-8031-2614-5