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EDX investigation of evaporative losses during the EB melting of SS316 Ritchie, Mark Thomas
Abstract
Changes in chemical composition due to evaporative losses during the EB (electron beam) melting of SS316 have been studied via x-ray analysis. A technique based on EDX has been developed to acquire, process, and interpret x-ray spectra in the UBC EB melting furnace. The present work consists of a series of experiments which correlate evaporative losses, and liquid surface composition to x-ray spectra for a number of different processing conditions. The parameters studied were beam voltage, beam power, and beam focus for two different mould types each with different fluid flow characteristics. An empirical relationship between measured x-ray intensities and surface composition is presented for the four major alloying elements in SS316( Mo, Cr, Fe, and Ni) and is considered to be accurate within ±1.5 at.%. The liquid surface.composition was found to be equal to the bulk liquid composition at the centreline, and to be depleted in Cr toward the edges. This relationship, however, does not hold for highly focussed, high power beams in the ceramic mould. In addition to the experiments, a numerical model was developed to predict the heat transfer and fluid flow within the molten pool for the experimental conditions. It was found that variations in beam power, and surfactant levels can have a significant effect on the evaporation and mixing characteristics in the pool when the electron beam is highly focussed.
Item Metadata
Title |
EDX investigation of evaporative losses during the EB melting of SS316
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1997
|
Description |
Changes in chemical composition due to evaporative losses during the EB
(electron beam) melting of SS316 have been studied via x-ray analysis. A technique
based on EDX has been developed to acquire, process, and interpret x-ray spectra in the
UBC EB melting furnace.
The present work consists of a series of experiments which correlate evaporative
losses, and liquid surface composition to x-ray spectra for a number of different
processing conditions. The parameters studied were beam voltage, beam power, and
beam focus for two different mould types each with different fluid flow characteristics.
An empirical relationship between measured x-ray intensities and surface composition is
presented for the four major alloying elements in SS316( Mo, Cr, Fe, and Ni) and is
considered to be accurate within ±1.5 at.%. The liquid surface.composition was found to
be equal to the bulk liquid composition at the centreline, and to be depleted in Cr toward
the edges. This relationship, however, does not hold for highly focussed, high power
beams in the ceramic mould.
In addition to the experiments, a numerical model was developed to predict the
heat transfer and fluid flow within the molten pool for the experimental conditions. It
was found that variations in beam power, and surfactant levels can have a significant
effect on the evaporation and mixing characteristics in the pool when the electron beam is
highly focussed.
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Extent |
13045611 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-04-20
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0078605
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1997-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.