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U.S. Department of Energy
Office of Scientific and Technical Information

Subgrain refinement strengthening. Annual report, October 1, 1975--September 30, 1976

Technical Report ·
OSTI ID:7311504

A study of subgrain refinement strengthening in ferritic alloys was performed. The alloys were selected from two groups: model alloys and alloys from the LMFBR advanced alloy development program. E-Brite 26-1 was selected as the model ferritic alloy. HT-9 and EM-12 were the advanced alloys selected for evaluation; however, the investigation of EM-12 was terminated since it was dropped from the advanced alloy development program. Torsion and compression tests were employed to study the influence of the subgrain structure on the mechanical properties of these alloys. These two forms of deformation are used to achieve the large strains necessary to study the development of subgrains. The E-Brite 26-1 was tested in torsion to very large strains to study the changes occurring in the subgrain size, dislocation density, and subgrain boundary perfection. Compression testing was employed to establish the relationship between strain rate and flow stress. In addition, strain rate change tests were performed in compression to evaluate the stress-strain rate relationship under constant structure conditions. Transmission electron microscopy studies have revealed that a well developed substructure is present in the HT-9 alloy following heat treatment. Subsequent torsion tests at a temperature of 700/sup 0/C and a strain rate of 6 x 10/sup -3/s/sup -1/ have shown that the refined substructure can have a significant influence on the flow stress of the alloy.

Research Organization:
Stanford Univ., CA (USA). Dept. of Materials Science and Engineering
DOE Contract Number:
EY-76-S-03-0326-038
OSTI ID:
7311504
Report Number(s):
SAN-326-38-X6
Country of Publication:
United States
Language:
English