Award Date

1-1-2004

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Mechanical Engineering

First Committee Member

Ajit K. Roy

Number of Pages

53

Abstract

This investigation is focused on the evaluation of residual stresses in target structural materials due to plastic deformation and welding by using both destructive ring-core (RC) method and nondestructive techniques including positron annihilation spectroscopy (PAS), neutron diffraction (ND) and x-ray diffraction (XRD) methods. Materials tested were austenitic Type 304L SS and martensitic Alloys EP-823 and HT-9. Types of specimen tested include cold-worked (CW), three-point-bent and welded specimens consisting of similar and dissimilar materials. The CW specimens showed increased residual stresses with an increase in cold reduction level. Measurements made on the welded specimens revealed higher residual stresses close to the fusion line (FL), which became reduced at distances away from the FL. Comparisons of RC data to those obtained on CW and welded specimens by the ND, PAS and XRD methods showed consistent stress patterns. Metallographic evaluations by optical microscopy revealed microstructures characteristic of austenitic and martensitic stainless steel showing the weld metal, heat-affected-zone and the base metal.

Keywords

Characterization; Materials; Measurements; Metallurgical; Residual; Stress; Structural; Target

Controlled Subject

Materials science; Materials science; Mechanical engineering

File Format

pdf

File Size

1679.36 KB

Degree Grantor

University of Nevada, Las Vegas

Language

English

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