skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Effect of niobium, molybdenum, and titanium on the solidification structures of Fe-C-Cr alloys

Abstract

The solidification processes and structures of Fe-15% Cr alloys with 2.4% to 3.4% C and 0% to 2.15% Nb were investigated metallographically. In addition, the effects of molybdenum and titanium on the solidification structures were also studied. The solidification of a Fe-2.42% C-15% Cr-1.45% Nb alloy started by the precipitation of primary austenite dendrites and then followed by the eutectic reactions of (..gamma.. + NbC) and (..gamma.. + M/sub 7/C/sub 3/). With an increase in the niobium content of the alloys more NbC and fewer M/sub 7/C/sub 3/ were precipitated, and there was a tendency toward preferential crystallization of compact shape niobium carbide. The addition of molybdenum changed only the end of solidification, and Mo-rich carbide was precipitated from the remaining enriched liquid due to the segregation of molybdenum and solidified lastly. Mo-rich carbide appeared to be discontinuous and fine-dot structure on the polished plane; in three dimensions the morphology of Mo-rich carbide appeared to be continuous and helical-like structure. The as-cast structure consisted of pearlitic structure with the Cr/C ratio was 4.68 and the Cr/C ratio assuring an austenitic structure decreased when molybdenum was present. But the addition of niobium did not appear to affect the transformation of themore » matrix structure.« less

Authors:
Publication Date:
Research Org.:
Wisconsin Univ., Madison (USA)
OSTI Identifier:
6154358
Resource Type:
Thesis/Dissertation
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARBIDES; PRECIPITATION; CARBON ADDITIONS; METALLURGICAL EFFECTS; CHROMIUM ALLOYS; SOLIDIFICATION; IRON ALLOYS; MOLYBDENUM ALLOYS; TITANIUM ADDITIONS; ALLOYS; CARBON COMPOUNDS; PHASE TRANSFORMATIONS; SEPARATION PROCESSES; TITANIUM ALLOYS; 360102* - Metals & Alloys- Structure & Phase Studies; 360202 - Ceramics, Cermets, & Refractories- Structure & Phase Studies

Citation Formats

Baik, H. Effect of niobium, molybdenum, and titanium on the solidification structures of Fe-C-Cr alloys. United States: N. p., 1987. Web.
Baik, H. Effect of niobium, molybdenum, and titanium on the solidification structures of Fe-C-Cr alloys. United States.
Baik, H. Thu . "Effect of niobium, molybdenum, and titanium on the solidification structures of Fe-C-Cr alloys". United States.
@article{osti_6154358,
title = {Effect of niobium, molybdenum, and titanium on the solidification structures of Fe-C-Cr alloys},
author = {Baik, H},
abstractNote = {The solidification processes and structures of Fe-15% Cr alloys with 2.4% to 3.4% C and 0% to 2.15% Nb were investigated metallographically. In addition, the effects of molybdenum and titanium on the solidification structures were also studied. The solidification of a Fe-2.42% C-15% Cr-1.45% Nb alloy started by the precipitation of primary austenite dendrites and then followed by the eutectic reactions of (..gamma.. + NbC) and (..gamma.. + M/sub 7/C/sub 3/). With an increase in the niobium content of the alloys more NbC and fewer M/sub 7/C/sub 3/ were precipitated, and there was a tendency toward preferential crystallization of compact shape niobium carbide. The addition of molybdenum changed only the end of solidification, and Mo-rich carbide was precipitated from the remaining enriched liquid due to the segregation of molybdenum and solidified lastly. Mo-rich carbide appeared to be discontinuous and fine-dot structure on the polished plane; in three dimensions the morphology of Mo-rich carbide appeared to be continuous and helical-like structure. The as-cast structure consisted of pearlitic structure with the Cr/C ratio was 4.68 and the Cr/C ratio assuring an austenitic structure decreased when molybdenum was present. But the addition of niobium did not appear to affect the transformation of the matrix structure.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {1}
}

Thesis/Dissertation:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this thesis or dissertation.

Save / Share: