Award Date

1-1-2008

Degree Type

Thesis

Degree Name

Master of Science in Mechanical Engineering (MSME)

First Committee Member

Ajit K. Roy

Second Committee Member

Brendan O'Toole

Number of Pages

84

Abstract

Martensitic P91 grade steels containing 0.48, 0.96, 1.28 and 1.77 weight percent (wt%) silicon (Si) have been tested for evaluation of their tensile properties at temperatures ranging from ambient to 550°C. The effect of activation using accelerator-driven electron beams on the room-temperature tensile properties of steels containing 0.48 and 1.28 wt% Si has also been investigated. The results indicate that all four heats of steel exhibited dynamic strain ageing at temperatures up to 400°C. The activated specimens showed enhanced tensile strength but reduced ductility with increasing activation time, indicating radiation hardening of the tested materials. The electrochemically-polarized specimens showed more noble critical pitting potentials with increasing Si content due to the formation of more protective oxide films. While the tensile specimens tested at 550°C exhibited ductile failures, brittle failures were seen at ambient temperature. However, all activated specimens revealed cleavage facets, indicating predominantly brittle failures.

Keywords

Behaviors; Chronium; Corrosion; Effects; Molybdenum; Silicon; Steel; Temperature; Tensile

Controlled Subject

Mechanical engineering

File Format

pdf

File Size

2.05 MB

Degree Grantor

University of Nevada, Las Vegas

Language

English

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