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Conference Article: The effect of volume on the tensile strength of several nuclear-grade graphites

Strizak, J.P. (Oak Ridge National Lab., TN (United States))

Abstract

This report presents the results of a study on the effects of stress volume on the tensile strength of two nuclear-grade graphites. The materials selected were H-451, an extruded near-isotropic graphite manufactured by Great Lakes Carbon Corporation, and IG-110, a fine-grained isotropic molded graphite manufactured by Toyo Tanso Company, Ltd. The tensile properties of H-451 were examined extensively in the past in order to characterize the variability of strength within billets, between billets, and between lots. But, the variability within a billet was, for the most part, studied only casually. The problem was the strong influence of a limited sampling plan in describing the mean strength and the variability. Therefore, an extensive, statistically sound sampling plan has been devised to fully characterize the spatial variability within a single billet. The effects of stress volume are being reexamined by comparing the strengths of four specimen sizes covering a broad range in stress volume. Test results for four specimen sizes having gage diameters of 6.35, 9.53, 15.88, and 25.40 mm are reported for H-451 graphite. Likewise, tensile test results for the isotropic, high strength IG-110 graphite are reported.

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key words: failures; fracture mechanics; graphite; materials testing; mathematical models; microstructure; probabilistic estimation; reactor components; stresses; tensile properties; carbon
Reference:
Specialists' meeting on the status of graphite development for gas cooled reactors. Tokai, Ibaraki (Japan). 9-12 Sep 1991
International Atomic Energy Agency, Vienna (Austria)
IAEA-TECDOC--690, pp:233-241