Deformation of Zr-2.5 percent Nb Pressure Tubes with Orientation

摘要

The objective of this paper is to understand the anisotropy of the deformation behavior along the three major directions of the Zr-2.5 percent Nb pressure tube materials. Because the deformation behavior in the radial direction has never been established although the anisotropy of the DHC behavior might be attributed to the anisotropy of the deformation. The small tensile specimens with a gage length of about 2 mm were machined and tested from room temperature to 560 deg C. The validity of the results from the small tensile specimens were checked by comparison with those from the larger specimens, an were found to be comparable. The stress-strain curves in both the transverse and radial directions showed similar trends except the level of stress, however, those in the longitudinal direction appeared to be different. The yield and the tensile strengths were low in the transverse, longitudinal, and radial directions in the range of 100 to 500 deg C. These behaviors could be explained using the deformation mechanisms and the texture of the material. The mechanical properties in the radial direction were successfully obtained using the small tensile specimens.