Effect of grain shape and texture on equi-biaxial creep of stress relieved and recrystallized zircaloy-4

Murty, K. Linga; Tanikella, B. V.; Earthman, James C.

doi:10.1016/0956-7151(94)90431-6

Cited by 26 publications

(12 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Similar trend has also been noticed in Zirlo [6]. Murty et al [16,17] showed that a good correlation for the CWSR Zircaloy can be obtained by considering stress enhancement occurring in the hoop direction during grain boundary sliding. …”

Section: Effect Of Grain Shape On Creep Anisotropysupporting

confidence: 58%

Deformation Microstructures and Creep Mechanisms in Advanced ZR-Based Cladding Under Biazal Loading

Murty¹

2008

View full text Add to dashboard Cite

Section: Effect Of Grain Shape On Creep Anisotropysupporting

confidence: 58%

Deformation Microstructures and Creep Mechanisms in Advanced ZR-Based Cladding Under Biazal Loading

Murty¹

2008

View full text Add to dashboard Cite

“…At 673 K, the exponent of 5 was observed when the regime. If the stress exponent remains constant with temperature, i.e., n ϳ 4, from Figure 17(b), the activation energy strain rate was lower than about 3.6 ϫ 10 Ϫ5 h Ϫ1 , [22] whereas at 773 K, n Ϸ 4 when the rates were of the order of 1 ϫ Q is ϳ25 kcal/mol (ϳ1.1 eV), namely, not very different than the value found here for temperatures higher than 473 10 Ϫ7 h Ϫ1 . [38] Akhtar [39,40] obtained a value for the stress exponent of K. On the other hand, if the activation energy remains constant with temperature, then from Figure 17(b), n ϳ 7.5, 3.5 and 4.3 for basal and prismatic slip, respectively, in Zr single crystals tested at temperatures higher than 850 K. namely, higher than the value found here.…”

Section: Experimental Procedures and Materialsmentioning

confidence: 97%

“…Finally, it is worth noting that higher deviatoric component of the applied stress has the form strains in the axial direction were also observed in equibiaxial creep experiments of recrystallized ZIRCALOY-4* of the hoop stress. Namely, all three diagonal components are nonzero and the component in the axial direction is tubing tested at 673 K. [22] Figures 13 and 14 show the total shear strain vs time plots about 6 pct higher than that in the transverse direction of the specimen. from the torsion tests at 523 and 583 K. It is again evident …”

Section: Experimental Procedures and Materialsmentioning

confidence: 98%

See 1 more Smart Citation

Analysis of steady-state thermal creep of Zr-2.5Nb pressure tube material

Christodoulou

Chow

Turner

et al. 2002

Metall Mater Trans A

View full text Add to dashboard Cite

The steady-state thermal creep rate in the axial and transverse directions of Zr-2.5Nb of pressure tubes, used in CANDU nuclear reactors, was determined. The data were obtained both from tensile samples having their tensile axes cut along the axial and transverse directions of the pressure tubes and from small-sized, thin-walled tubes, i.e., "mini" tubes stressed either in torsion or by internally pressurizing capsules manufactured from the mini tubes, or by additionally applying an external, axial load on these internally pressurized capsules. The temperature range of the data was from 373 to 596 K (100 ЊC to 323 ЊC) and the duration of the tests was from about 1500 hours to over 12,000 hours.The tests were carried out over a sufficiently long time for the creep rate to be measurable in the steady-state creep regime. It was found that the steady-state creep rate depends on stress in a nonlinear fashion and the stress exponent over the entire temperature range was about four. This value is consistent with the values measured earlier on other zirconium alloys. The activation energy Q was found to be about 21 and 10 kcal/mol for temperatures above and below 475 K (ϳ200 ЊC), respectively. These values are lower than those measured by other investigators on the same material at higher temperatures but similar to values found on other Zr alloys at low temperatures. It appears that Q is dependent on temperature and its value is consistent with the presence of dynamic strain aging (DSA). The results of this study were analyzed with a polycrystalline, nonlinear self-consistent model that take into account the crystallographic texture of the material. This model was used to derive the values of critical resolved shear stress (CRSS), which are consistent with prismatic, basal, and pyramidal glide. By using these values and the apparent temperature dependence of Q, it was shown that this model predicts well the steady-state creep rate over the entire temperature range and under very different stress states.

show abstract

“…Incorporation of the stress enhancement factor along the hoop direction in conjunction with CODF-creep model with dominant prismatic slip yielded predictions of creep anisotropy in good agreement with the experimental data for CWSR ZircaIoy-4. 14 This article presents results of a recent study on the equibiaxial creep characteristics of Ti-3AI-2.SV13 tubing along with Zircaloy-4 in both CWSR and recrystallized conditions along with their crystallographic textures, COOFs, and the creep model predictions with the stress-enhancement factor included in the CWSR cases. We note that the consideration of the superimposed effects of grain-shape anisotropy and crystallographic texture adequately explained the observed creep anisotropy following cold-work and stress-relief anneal.…”

Section: Introductionmentioning

confidence: 99%

Effects of grain-shape anisotropy and texture on balanced-biaxial creep of Ti and Zr alloys

Earthman

Murty

Tanikella

et al. 1994

JOM

View full text Add to dashboard Cite

Biaxial creep behaviors of stress-relieved and recrystallized thin-walled tubing of Ti-3AI-2.SV and Zircaloy-4 are considered under equal hoop and axial stresses by internal pressurization superimposed with axial load. Both hoop and axial strains were monitored and the ratio of the strain rate along the hoop to that along the axial directions is considered to represent the degree of anisotropy.In both of these alloys, relatively weak hoop direction in cold-worked stress-relieved (CWSR) materials became slightly stronger following recrystallization. Crystallographic texture was considered in terms of x-ray pole figures from which the crystallite orientation distribution functions (CODFs) were derived and crystal plasticity model with slip dominant on prism planes was combined with the CODFs to predict the creep anisotropy. While good correlation was noted for recrystallized materials, distinct deviations are observed for CWSR that are believed to arise from grain shape anisotropy. The relatively small (equiaxed) grain size along the hoop and radial directions results in grain boundary sliding leading to stress enhancements along these directions. This anisotropy in grain boundary sliding is shown to explain the observed deviations.

show abstract

Effect of grain shape and texture on equi-biaxial creep of stress relieved and recrystallized zircaloy-4

Cited by 26 publications

References 13 publications

Deformation Microstructures and Creep Mechanisms in Advanced ZR-Based Cladding Under Biazal Loading

Deformation Microstructures and Creep Mechanisms in Advanced ZR-Based Cladding Under Biazal Loading

Analysis of steady-state thermal creep of Zr-2.5Nb pressure tube material

Effects of grain-shape anisotropy and texture on balanced-biaxial creep of Ti and Zr alloys

Contact Info

Product

Resources

About