کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1581346 | 1514868 | 2008 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Crack tip stress effect on delayed hydride cracking velocity of Zr–2.5Nb tubes Crack tip stress effect on delayed hydride cracking velocity of Zr–2.5Nb tubes](/preview/png/1581346.png)
Using our new delayed hydride cracking (DHC) model, we scrutinized Pan's DHC test results of a cold-worked Zr–2.5Nb tube after neutron irradiation. DHC velocity at 240 °C of the Zr–2.5Nb tube increased gradually at neutron fluences below 5 × 1025 n/m2 (E > 1 MeV) and leveled off to a constant value at higher neutron fluences over it. This neutron fluence dependence of the DHC velocity was found to be similar to that of the Nb concentration in the β-Zr, not that of its tensile stress, which is hard to understand in view of the old DHC models. Normalization of the DHC velocity by hydrogen diffusivity or DH is found to lessen the apparent yield stress effect on the DHC velocity of Zr–2.5Nb tubes. Consequently, it is demonstrated that the DHC velocity of the Zr–2.5Nb tubes is governed not by the crack tip stresses but by hydrogen diffusion, corroborating the validity of the new DHC model.
Journal: Materials Science and Engineering: A - Volume 490, Issues 1–2, 25 August 2008, Pages 146–150