PHYSICAL PROPERTIES

PHYSICAL PROPERTIES DOE-HDBK-1017/1-93 Properties of Metal PHYSICAL PROPERTIES 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 various materials. EO 1.14 DEFINE the following terms: a. Strength b. Ultimate tensile strength c. Yield strength d. Ductility e. Malleability f. Toughness g. Hardness EO 1.15 IDENTIFY how slip effects the strength of a metal. EO 1.16 DESCRIBE the effects on ductility caused by: a. Temperature changes b. Irradiation c. Cold working EO 1.17 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. MS-02 Page 20 Rev. 0