2010 Volume 51 Issue 4 Pages 652-658
Crystallographic texture and corrosion of zirconium alloy tube with pilgering were studied. Average grain size of the cross-sectional surface of the tube was changed from 28 μm to 11 μm by 1st pilgering, and to 8 μm by 2nd pilgering. Aspect ratios of the elongated grains on longitudinal surface of as-received, 1st and 2nd pilgered tubes are 1, 6 and 12, respectively. Micro-hardnesses of the tubes are 172, 218 and 246 Hv for their cross sectional surfaces and 180, 233 and 252 Hv for their longitudinal surfaces, respectively. Pilgering results in increasing the (0001) basal and {10\\bar10} prismatic pole densities to TD (tangential direction) split type and AD (axial direction) concentration type, respectively. A preferred orientation is mainly formed by 1st pilgering. Further pilgering produces a texture of (\\bar12\\bar14)[10\\bar10] with a significant spread around [10\\bar10] parallel to AD. Corrosion potential and corrosion rate of the zirconium alloy tubes in dearated aqueous 5% NaCl solution (pH=6.3) at 20°C are in the range of −0.552∼−0.767 VSHE and 1.88×10−7∼12.02×10−7 A/cm2, respectively. Crystallographic anisotropy influences corrosion behavior of the zirconium alloy tubes. Pilgering results in reducing corrosion potential and increasing corrosion rate due to grain size refinement and increased dislocation density rather than crystallographic texture.
