Bush, S. H.
Consulting metallurigst, Hanford Laboratories, Hanford Atomic Products Operation, Richland, Wash.
Tobin, J. C.
Manager, Reactor Metals Research, Hanford Laboratories, Hanford Atomic Products Operation, Richland, Wash.
Pages: 15 Published: Jan 1965
Stainless steels represent one of the major groups of structural and fuel cladding materials used in nuclear reactors. These steels have been used extensively in civilian power reactors. This paper reviews the performance of ferritic, martensitic, austenitic, and precipitation hardening stainless steels when exposed to neutrons, and the effects of reactor environment, whether water, gas, or liquid metal.
The effects of neutron irradiation on the mechanical properties of stainless steels are examined. Generally, exposure to neutron flux increases the yield strength substantially more than it does the ultimate tensile strength. This is accompanied by marked decreases in ductility. Uniform elongation becomes extremely small after exposures in the range 1020 to 1021 nvt.
The dynamic properties of the stainless steels such as creep, stress rupture, and low cycle fatigue are reviewed, based on the limited data available. The effects of stress application to stainless steels while exposed to neutrons are also discussed.
Specific consideration is given to surface corrosion, oxidation, and stress corrosion where the neutron induced heat flux plays a major role. Potential limitations to the use of these steels by such reactions are considered, as are possible solutions to the problems.
Certain indirect effects of a neutron environment such as thermal cycling due to varying gamma flux during reactor startup and shutdown and the deleterious effects of such cycling are considered in structural components and in fuel cladding. Other indirect effects unique to nuclear reactors such as the interaction of fuel with stainless cladding are discussed briefly.
Paper ID: STP43737S