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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), the Idaho State University (ISU), and the Los Alamos National Laboratory (LANL) is to evaluate the feasibility of determining residual stresses in cold-worked, plastically-deformed (bent), and welded materials using a nondestructive method based on positron annihilation spectroscopy (PAS). This technique uses γ-rays from a small MeV electron Linac to generate positrons inside the sample via pair production. This method is known to have capabilities of characterizing defects in thick specimens that could not be accomplished by conventional positron technique or other nondestructive methods. The generated data will be compared to those obtained by other methods such as neutron diffraction and X-ray diffraction (for thin specimens), and ring-core (destructive-for thick specimens) methods. During the initial phase, residual stresses induced in experimental heats of austenitic Type 304L stainless steel, and martensitic Alloy EP-823 have been determined by X-ray diffraction (XRD), PAS and ring-core techniques. More recently, efforts are ongoing to include Alloy HT-9, another martensitic stainless steel to perform similar measurements on this alloy using all four techniques. Later, irradiated materials may be evaluated. Low-level radiation will be induced in the test specimens at the ISU, followed by residual stress measurements using the PAS method.


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

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


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

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62 KB




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