| Popis: |
``Lower-bound`` initiation toughness of A 533 B reactor-grade steel was determined over the temperature range from 0 to 57{degrees}C by using a modified-Charpy specimen. The lower-bound measurements were attained by utilizing the following procedures: (1) dynamic loading, (2) modification of the geometry of the specimen, and (3) axial precompression of the notch. The report describes in detail the key features of the modified geometry, the method of precompressing the specimens, and the straingage procedure. The dynamic initiation toughness K{sub Id}, which correlates with the lower-bound toughness, was determined by analyzing strain-time records from the specimen. The results from a fractographic analysis were correlated with those from the strain-time analysis. An empirical correlation was developed relating K{sub I} to the energy absorbed (E{sub CV}) during the fracture of the specimen. Finally, the lower-bound toughness from the same material established in other programs. 31 refs., 11 figs. |
