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The solidification and weldability of nickel base alloys that simulate the base compositionrange of Alloy 52i with systematic variations of C, N, Nb, Ti, Si, and Mg were studiedusing solidification modeling, differential thermal analysis (DTA), microstructuralcharacterization techniques, and Varestraint weldability testing. The solidification path forthese systems generally follows a primary L → γ reaction, followed by a eutectic-type L→ (γ + NbC) reaction which results in a smaller solidification temperature range and/or aeutectic-type L → (γ + Laves) reaction which results in a larger solidification temperaturerange. Depending on the C and N concentrations, other carbo-nitride phases can also form.Increased carbon, lowered niobium, and moderate nitrogen were found to promote Nb-richphase formation, prohibit Laves phase formation, and minimize the solidificationtemperature range. Increasing niobium, titanium, and nitrogen resulted in large blocky TiNphases that formed in the dendrite cores and Laves phase formation at the crack tip,increased solidification temperature ranges, and reduced weldability. Silicon was found topromote Laves phase formation, increase the solidification cracking range, and increasesolidification cracking susceptibility. In this work, the relation between alloy composition,solidification behavior, and weldability is described to aid in alloy development of solidification cracking resistant alloys for naval nuclear applications.
Full Title
Effect of Alloying Elements on the Solidification Behavior and Weldability of Nickel Base Alloy 52
Member of
Contributor(s)
Creator: Fraser, Allison
Thesis advisor: DuPont, John N.
Publisher
Lehigh University
Date Issued
2020-01-01
Date Valid
2021-01-29
Language
English
Type
Genre
Form
electronic documents
Department name
Materials Science and Engineering
Digital Format
electronic documents
Media type
Creator role
Graduate Student
Subject (LCSH)
Embargo Date
2021-01-29
Citation
@mastersthesis{frasernd,
title = {Effect of Alloying Elements on the Solidification Behavior and Weldability of Nickel Base Alloy 52},
author = {Fraser, Allison},
publisher = {Lehigh University},
keywords = {Alloy Development, Modeling, Nickel Base, Solidification, weldability, Welding},
abstract = {The solidification and weldability of nickel base alloys that simulate the base compositionrange of Alloy 52i with systematic variations of C, N, Nb, Ti, Si, and Mg were studiedusing solidification modeling, differential thermal analysis (DTA), microstructuralcharacterization techniques, and Varestraint weldability testing. The solidification path forthese systems generally follows a primary L → γ reaction, followed by a eutectic-type L→ (γ + NbC) reaction which results in a smaller solidification temperature range and/or aeutectic-type L → (γ + Laves) reaction which results in a larger solidification temperaturerange. Depending on the C and N concentrations, other carbo-nitride phases can also form.Increased carbon, lowered niobium, and moderate nitrogen were found to promote Nb-richphase formation, prohibit Laves phase formation, and minimize the solidificationtemperature range. Increasing niobium, titanium, and nitrogen resulted in large blocky TiNphases that formed in the dendrite cores and Laves phase formation at the crack tip,increased solidification temperature ranges, and reduced weldability. Silicon was found topromote Laves phase formation, increase the solidification cracking range, and increasesolidification cracking susceptibility. In this work, the relation between alloy composition,solidification behavior, and weldability is described to aid in alloy development of solidification cracking resistant alloys for naval nuclear applications.},
language = {English},
}