ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The influence of grain-boundary hydride (MgH2) precipitation on the mechanical properties of Magnox AL80 has been investigated by carrying out slow tensile and fatigue tests. The presence of hydride precipitates at some grain boundaries was found to have a detrimental effect on the slow tensile ductilities at the lower end (20 to 40% h−1) of the range of strain rates used (20 to 2000% h−1) at 250° C and at 20% h−1 at 300° C. Grain-boundary cavities caused by the dissociation of the hydride precipitates were introduced either byin situ thermal treatment prior to testing at 250° C or by testing at higher temperatures and also resulted in lower tensile ductilities at slow strain rates. The fatigue lives of Magnox AL80 were not significantly influenced by the presence of grain-boundary hydride precipitates or cavities due to the dissociation of the precipitates. This is due to the majority of the boundaries being unsuitably oriented to experience high shear stresses. Long-term ageing at 450° C was found to reduce the subsequent fatigue strength at that temperature and this effect is associated with the boundaries becoming more prone to migration during fatigue cycling.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00551944
