摘要:
In a zirconium-alloy fuel element cladding, a method for generating regions of coarse and fine intermetallic precipitates across the cladding wall is provided. The method includes steps of specific heat treatments and anneals that coarsen precipitates in the bulk of the cladding. The method also includes at least one step in which an outer region (exterior) of the cladding is heated to the beta or alpha plus beta phase, while an inner region (interior) is maintained at a temperature at which little or no metallurgical change occurs. This method produces a composite cladding in which the outer region comprises fine precipitates and the inner region comprises coarse precipitates.
摘要:
A method for controlling hydrogen charging of hydride forming metals through a window of a superimposed layer of a non-hydriding metal overlying the portion of the hydride forming metals to be charged.
摘要:
A method for fabricating a composite cladding comprised of a moderate-purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube which improves corrosion resistance. The improved corrosion resistance of the liner is accomplished by suitable heat treatment of the Zircaloy-zirconium composite cladding to allow diffusion of alloying elements, notably Fe and Ni, from the Zircaloy into the zirconium, in particular, to the inner surface of the zirconium liner. This diffusion anneal reduces the undesirable tendency of zirconium liner to oxidize rapidly.
摘要:
A method of manufacturing components made of zirconium-based alloy by combining heat treatment with thermal sizing. The heat treatment includes heating the component to a temperature which initiates the transformation from a hexagonal close-packed crystallographic phase of uniform texture to a body-centered cubic crystallographic phase and then quenching to a quench temperature at a rate which initiates transformation to a hexagonal close-packed crystallographic phase having a texture factor f.sub.L =0.28-0.38. The thermal sizing includes heating the component to a temperature less than the quench temperature, but sufficient to anneal the component, and then cooling. Preferably, the thermal sizing is performed twice: before and after the heat treatment.
摘要:
An alloy having improved resistance to hydriding as well as good corrosion resistance, adequate strength, fabricability and irradiation growth. These properties make the new alloy exceptionally suited for use in boiling water reactor components such as fuel channels, fuel cladding and fuel rod spacers. The class of alloys includes zirconium-based alloys having about 0.3-1.2% tin, about 0.8-1.4% chromium, about 0.05-0.7% iron, and the remainder substantially zirconium.
摘要:
A cladding tube having a cross-section and including (1) a zirconium alloy outer circumferential substrate having an inner surface and having one or more alloying elements, (2) a zirconium barrier layer bonded to the inner surface of the outer circumferential substrate and being alloyed with the one or more alloying elements, and (3) a zirconium alloy inner circumferential liner bonded to the inner surface of the zirconium barrier layer. The barrier layer will have a concentration profile including a diffusion layer extending from the barrier layer's inner surface (facing nuclear fuel) to the barrier layer's interior (between the barrier layer's inner and outer surfaces). At the interior edge of the diffusion layer, there will be substantially no alloying elements. At the outer edge of the diffusion layer (the barrier layer's inner surface), the maximum concentration of alloying elements will occur.
摘要:
A method for fabricating a composite cladding comprised of a moderate-purity metal barrier of zirconium metallurgically bonded on the inside surface of a zirconium alloy tube which improves corrosion resistance. The improved corrosion resistance of the liner is accomplished by suitable heat treatment of the Zircaloy-zirconium composite cladding to allow diffusion of alloying elements, notably Fe and Ni, from the Zircaloy into the zirconium, in particular, to the inner surface of the zirconium liner. This diffusion anneal reduces the undesirable tendency of zirconium liner to oxidize rapidly.
摘要:
A composite zirconium alloy component that exhibits a reduced propensity for irradiation growth and enhanced corrosion resistance when in a radiation field. The component is formed to have an inner core and two oppositely-disposed outer layers that are metallurgically bonded to the inner core. The inner core and the outer layers are formed from two different zirconium alloys, with the inner core alloy contributing to the ability of the component to resist dimensional distortions as a result of irradiation growth, while the outer layer alloy contributes to the ability of the component to resist corrosion. As such, the alloys are combined within the component in a manner that exploits the different corrosion and irradiation-resistance properties of the alloys.
摘要:
A Zircaloy cladding having an outer region comprising fine precipitates and inner region comprising coarse precipitates is provided. The outer region comprises about 10% and the inner region comprises about 90% of the cladding wall thickness. Such Zircaloy tubing is resistant to propagation of cracks and at the same time resistant to corrosion in boiling water reactors (BWR). Resistance to damage caused by the pellet-cladding-interaction can be achieved by standard application of a zirconium or zirconium-alloy liner on the tubing inside surface.
摘要:
In a zirconium-alloy fuel element cladding, a method for generating regions of coarse and fine intermetallic precipitates across the cladding wall is provided. The method includes steps of specific heat treatments and anneals that coarsen precipitates in the bulk of the cladding. The method also includes at least one step in which an outer region (exterior) of the cladding is heated to the beta or alpha plus beta phase, while an inner region (interior) is maintained at a temperature at which little or no metallurgical change occurs. This method produces a composite cladding in which the outer region comprises fine precipitates and the inner region comprises coarse precipitates.