Masters Theses

Vintee Singh

Abstract

"The objective of this research is to study the effects of changing the melt and ladle practices (deoxidation, slag, refractory types, etc.) in steel foundries on the cleanliness and toughness of steel castings. This study used an automated inclusion analyzer ASPEX PICA-1020, which provides a rapid and accurate method for determining the composition, size, number, and spacing of the inclusions present in steel samples. The first step in this research was to complete a series of industrial tests to benchmark the current foundry ladle practices with respect to cleanliness of the cast steel. Trials were conducted at steel foundries using induction and arc furnaces of capacity 1 to 20 tons. Samples collected from the furnace, ladle, and cast products were analyzed for inclusions, using ASPEX, and for their oxygen content, using a Leco analyzer. The next step was to conduct industrial trials to study the effects of ladle metallurgy (Ca-treatment through wire injection, gas stirring, etc.) on inclusions and mechanical properties of the casting. Several 1000 lb ladles of steel were treated with different amounts and speeds of Ca and CaSi wire injection and argon stirring. The inclusions and the oxygen content were analyzed in the samples collected. Charpy impact tests were conducted on the cast products to observe the relationship between inclusions and the toughness of the cast steel. FLUENT modeling was done to understand the effects of various parameters of the ladle-practice on flotation of inclusions. In all the heats conducted with Ca-additions in the ladle, the fraction of area covered by inclusions and the total oxygen was found to decrease after the Ca-treatment. The toughness of the castings were found to be indirectly proportional to the inclusions and increased with an increase in the amount of Ca-added in the ladle"--Abstract, page iii.

Advisor(s)

Peaslee, Kent D., 1956-2013

Committee Member(s)

Richards, Von
Lekakh, S. N. (Semen Naumovich)

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering

Sponsor(s)

Benét Laboratories
United States. Department of the Army

Publisher

Missouri University of Science and Technology

Publication Date

2009

Pagination

xi, 80 pages

Note about bibliography

Includes bibliographical references (pages 103-112).

Rights

© 2009 Vintee Singh, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Steel -- Inclusions
Steel castings -- Testing
Steel foundries -- Equipment and supplies -- Testing
Calcium -- Thermal properties

Thesis Number

T 10218

Print OCLC #

862120696

Electronic OCLC #

862120843

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