SEDL / STP / STP1366-EB / STP12447S

Neutron-Induced Evolution of Mechanical Properties of 20% Cold-Worked 316 Stainless Steel as Observed in Both Miniature Tensile and TEM Shear Punch Specimens

Hamilton, ML
Senior Scientist, Senior Staff Scientist, Pacific Northwest National Laboratory, Richland, WA

Garner, FA
Senior Scientist, Senior Staff Scientist, Pacific Northwest National Laboratory, Richland, WA

Hankin, GL
Graduate Student, Professor, I.P.T.M.E., Loughborough University, Leicestershire,

Faulkner, RG
Graduate Student, Professor, I.P.T.M.E., Loughborough University, Leicestershire,

Toloczko, MB
Washington State University, Pullman, WA

Pages: 15    Published: Jan 2000

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Abstract

Three heats of 20% cold worked 316 stainless steel were irradiated in the Materials Open Test Assembly of the Fast Flux Test Facility producing data at three or four irradiation increments to doses ranging from 12 to 88 dpa. There were five irradiation temperatures ranging from 400 to 730°C. The specimens were in two forms, standard TEM microscopy disks and miniature tensile specimens, irradiated side by side. The tensile specimens were tested at room temperature, and the TEM disks were subjected to a shear punch test, also at room temperature. Both methods yielded very similar results, showing that the mechanical properties of these steels quickly approached and then maintained saturation levels of yield strength. The saturation levels were only slightly dependent on heat identity, but were strongly dependent on irradiation temperature. Ductility decreased with increasing exposure, however.

It was shown that the tensile and shear punch data can be well-correlated with simple expressions that reflect the differences in stress state and physical constraints of the two techniques. This allows the application of the shear punch technique to situations where steep neutron flux or gamma heating gradients, insufficient irradiated material or insufficient reactor volume prevent the use of even small tensile specimens.