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Eisengusswerkstoffe
Dokumenten-Nummer: 57861
Tagungsbeitrag
Fras, Edward; Gorny, M.
Publikationssprache: Englisch
Mechanism of Dissolved Sulfur Influence on the Transition from Graphite to Cementite Eutectic in
Cast Iron
Mechanismus des Einflusses von gelöstem Schwefel auf den Übergang vom Graphit- zum Zementiteutektikum beim
Gusseisen
In this work an analytical solution is used to explain the mechanism of dissolved sulfur influence on the transition from
graphite to cementite eutectic in cast iron. It is found that this transition can be related to (1) the nucleation potential of
graphite (characterized by nucleation coefficients, N(ind s) and b (2) the growth rate coefficient of graphite eutectic cell,
mu (3) the temperature range, Delta T(ind sc) = T(ind s) - T(ind c) (where T(ind s) and T(ind c) is the equilibrium
temperature of the graphite eutectic and the formation temperature of the cementite eutectic respectively) and (4) the
liquid volume fraction, fl after solidification of the pre-eutectic austenite. It has been shown that the main impact of
dissolved sulfur on the transition from graphite to cementite eutectic consists in reducing the growth rate of graphite
eutectic cell. Analytical equations were presented to describe the absolute chilling tendency, CT, and the chill, w of cast
iron. Finally, it has been shown that as dissolved sulfur content in cast iron increases, the eutectic cell count, N, the
maximum degree of undercooling at the onset of graphite eutectic solidification, Delta T(ind m), and the chilling
tendency index, CT and chill, w increase as well.
AGH University of Science and Technology, Krakow, PL
Key Engineering Materials
Erscheinungsjahr 2010
S. S.137-142
Seiten/Bilder/Tabellen/Quellen: 6S
Eisengusswerkstoffe
Dokumenten-Nummer: 57801
Zeitschriftenaufsatz
Fras, Edward; Gorny, Marcin
Publikationssprache: Englisch
Mechanism of phosphorous influence on the chilling tendency and chill of cast iron
Einfluss von Phosphor auf den Abschreckverlauf und Abschreckkokille bei Gusseisen
In this work an analytical solution is used to explain the mechanism of phosphorous influence on the transition from
graphite to cementite eutectic in cast iron. It is found that this transition can be related to (1) the nucleation potential of
graphite, characterized directly by the nucleation coefficients N(ind s) and b, (2) the growth rate coefficient of graphite
eutectic cell, micro, (3) the temperature range, Delta T(ind sc) = T(ind s) - T(ind c) (where T(ind s) and T(ind c) are the
equilibrium temperature of the graphite eutectic and formation temperature of the cementite eutectic respectively) and
(4) the liquid volume fraction, f(ind l), after solidification of the pre-eutectic austenite. Analytical equations were used to
describe the absolute chilling tendency, CT and in consequence the chill, w of cast iron. This theory is experimentally
verified using phosphorous as an example. Influence of phosphorous on estimation of N(ind s) , b and micro values is
presented. It has been shown that increasing phosphorous leads to increasing the critical cooling rate, C(ind cr). In
consequence as content of phosphorous decreases the chilling tendency, CT and the width of chill, w increase. The
main impact of phosphorous on the chilling tendency and chill is related with increasing the graphite nucleation
potential of cast iron.
AGH University of Science and Technology, Krakow, PL
Giessereiforschung
Erscheinungsjahr 2013
Heftnummer 1
S. S.2-10 (9 Seiten, 10 Bilder, 2 Tabellen, 19 Quellen)
Giesserei Literaturschau