Author: Arnaldo Homobono Paes de AndradePublisher:
ISBN:
Category : Nuclear fuel claddings
Languages : en
Pages : 310
Book Description
Subcritical Crack Growth in Zirconium Alloys
Author: Arnaldo Homobono Paes de AndradePublisher:
ISBN:
Category : Nuclear fuel claddings
Languages : en
Pages : 310
Book Description
Factors Controlling Hydrogen Assisted Subcritical Crack Growth in Zr-2.5Nb Alloys
Author: LA. SimpsonPublisher:
ISBN:
Category : Cracks
Languages : en
Pages : 22
Book Description
The delayed failure of cold-worked Zr-2.5Nb pressure tube. material has been studied using static load tests on compact-tension specimens containing hydrogen within the range ~ 10 to 400 ?g/g. The experimental approach was to measure crack velocity (V) as a function of crack tip stress intensity factor (K), temperature and hydrogen content, relate these data to fractographic and metallographic observations, and compare the results with recent models of hydrogen embrittlement. Slow crack growth was observed at all temperatures between 25 and 325 °C and at K values between ~ 10 and 50 MPam. Below 250°C, the V-K relationships exhibited two-stage behavior; at K > 15 to 20 MPam, the crack velocity was only weekly dependent on stress intensity, whereas at smaller K values, the crack velocity decreased rapidly with K, an indication of a threshold value of K ~ 5 to 10 MPam. The crack velocity increased with increase in temperature, although because of scatter in the data, this could not be expressed quantitatively. At 250°C and above, slow crack growth was not reproducible except after a thermal cycle. The thermal cycle produced a region of reoriented hydrides concentrated at the crack tip which significantly reduced the incubation period for crack growth and confirmed the important role of the hydride phase in the fracture process. Fractography showed that the features of the slow growth fracture were similar at all temperatures studied. The main observations were of ductile striations, or stretch zones, parallel to the crack front, with brittle, plate-like regions, some of which contained cleavage features, between the striations. A fracture mechanism is suggested which involves the repeated precipitation of hydride at the crack tip, followed by crack advance through this embrittled region, and crack arrest in the more ductile matrix, leading to discontinuous crack growth. This general mode of crack growth has been considered in a recent model for embrittlement in hydride-forming materials, the predictions of which show good agreement with the results from this study.
Hydride-induced crack growth in zirconium alloys
Author: R. DuttonHigh Cycle Fatigue Crack Growth of Two Zirconium Alloys
Author: Vegelapudi Subba RaoZirconium in the Nuclear Industry
Author: ASTM Committee B-10 on Reactive and Refractory Metals and AlloysPublisher: ASTM International
ISBN:
Category : Nuclear reactors
Languages : en
Pages : 694
Book Description
High Cycle Fatigue Crack Growth of Two Zirconium Alloys
Author: V. S. RaoZirconium in the Nuclear Industry
Author: George P. SabolPublisher: ASTM International
ISBN: 0803124996
Category : Microstructure
Languages : en
Pages : 953
Book Description
The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components
Author: Manfred P. PulsPublisher: Springer Science & Business Media
ISBN: 1447141954
Category : Science
Languages : en
Pages : 475
Book Description
By drawing together the current theoretical and experimental understanding of the phenomena of delayed hydride cracking (DHC) in zirconium alloys, The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Components: Delayed Hydride Cracking provides a detailed explanation focusing on the properties of hydrogen and hydrides in these alloys. Whilst the emphasis lies on zirconium alloys, the combination of both the empirical and mechanistic approaches creates a solid understanding that can also be applied to other hydride forming metals. This up-to-date reference focuses on documented research surrounding DHC, including current methodologies for design and assessment of the results of periodic in-service inspections of pressure tubes in nuclear reactors. Emphasis is placed on showing how our understanding of DHC is supported by progress in general understanding of such broad fields as the study of hysteresis associated with first order phase transformations, phase relationships in coherent crystalline metallic solids, the physics of point and line defects, diffusion of substitutional and interstitial atoms in crystalline solids, and continuum fracture and solid mechanics. Furthermore, an account of current methodologies is given illustrating how such understanding of hydrogen, hydrides and DHC in zirconium alloys underpins these methodologies for assessments of real life cases in the Canadian nuclear industry. The all-encompassing approach makes The Effect of Hydrogen and Hydrides on the Integrity of Zirconium Alloy Component: Delayed Hydride Cracking an ideal reference source for students, researchers and industry professionals alike.
Zirconium in the Nuclear Industry: Tenth International Symposium
Author: A. M. GardePublisher: ASTM International
ISBN: 0803120117
Category : Nuclear fuel claddings
Languages : en
Pages : 805
Book Description
Author: