Properties of Metal
Material is selected for various applications in a reactor facility based on its
physical and chemical properties. This chapter discusses the physical properties
of material. Appendix A contains a discussion on the compatibility of tritium with
DEFINE the following terms:
IDENTIFY how slip effects the strength of a metal.
DESCRIBE the effects on ductility caused by:
IDENTIFY the reactor plant application for which high
ductility is desirable.
Strength is the ability of a material to resist deformation. The strength of a component is
usually considered based on the maximum load that can be borne before failure is apparent. If
under simple tension the permanent deformation (plastic strain) that takes place in a component
before failure, the load-carrying capacity, at the instant of final rupture, will probably be less
than the maximum load supported at a lower strain because the load is being applied over a
significantly smaller cross-sectional area. Under simple compression, the load at fracture will
be the maximum applicable over a significantly enlarged area compared with the cross-sectional
area under no load.
This obscurity can be overcome by utilizing a nominal stress figure for tension and shear. This
is found by dividing the relevant maximum load by the original area of cross section of the
component. Thus, the strength of a material is the maximum nominal stress it can sustain. The
nominal stress is referred to in quoting the "strength" of a material and is always qualified by
the type of stress, such as tensile strength, compressive strength, or shear strength.