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University of Nevada, Las Vegas

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Las Vegas (Nev.)

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The purpose of this collaborative research project involving the University of Nevada, Las Vegas (UNLV) and the Idaho State University (ISU) is to evaluate the feasibility of determining residual stresses of welded, bent (three-point-bend), and cold-worked engineering materials using a new nondestructive technique based on positron annihilation spectroscopy. The proposed technique is to use x-rays from a small MeV electron Linac to generate positrons inside the sample via pair production. This method can be used for materials characterization and investigation of defects in thick samples that could not be accomplished by conventional positron technique or other nondestructive methods. The data generated will be compared to those obtained by other nondestructive methods such as neutron diffraction and x-ray diffraction, and a destructive method known as ring-core technique. Materials to be tested in the initial phase will be unirradiated austenitic (Type 304L) and martensitic (EP-823) stainless steels that will be welded, bent and cold-worked prior to the evaluation of their residual stresses. Metallurgical microstructures will also be evaluated. In addition, deformation characteristics in terms of dislocations and their movements resulting from welding and plastic deformation will be analyzed by transmission electron microscope (TEM). Later, irradiated Alloy EP-823, HT-9, and austenitic materials (Type 316L stainless steel and Alloy 718) will be included in this program.


Austenitic stainless steel; Deformations (Mechanics); Martensitic stainless steel; Nuclear reactors — Materials — Testing; Plasticity; Strains and stresses; Welded joints — Fatigue

Controlled Subject

Austenitic stainless steel; Martensitic stainless steel; Nuclear reactors--Materials--Testing


Materials Science and Engineering | Mechanical Engineering | Metallurgy | Oil, Gas, and Energy

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298 KB




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