STUDY OF EFFECT OF ZIRCONIA-GRAPHITE MATERIAL COMPOSITION
ON ITS PROPERTIES
A. V. Yagovtsev,
N. V. Obabkov,
and I. D. Kashcheev
Translated from Novye Ogneupory, No. 10, pp. 17 – 20, October, 2013.
Original article submitted June 3, 2013.
Contemporary oxide-graphite materials are analyzed. Density, ultimate strength in bending, and porosity of
zirconia-graphite materials are studied using experimental planning. The effect of various components on
properties of the materials obtained is evaluated.
Keywords: zirconia-graphite material, refractory for continuous steel casting, density, ultimate strength in
A main area for improvement of steel continuous casting
technology is an increase continuous billet casting machine
(CBCM) productivity and poured steel quality. Practice
shows that in order to accomplish this refractory objects with
increased life are required. The most critical assemblies of
the CBCM refractory channel are the protection pipes, stop-
per monoblocks, and submerged nozzles, providing transfer
of steel from a tundish into a crystallizer.
Previously submerged nozzles have been manufactured
predominantly from opaque quartz glass by technology in-
troduced in the Podolsk Refractory Component Plant and
Pervoural Dinas Plant . Since the end of the 1970s quartz
nozzles have been replaced by more effective corun
dum-graphite nozzles, which were produced in the Borovich
Refractory Combine and the Bogdanovich PO Refractories
by isostatic compaction [2, 3]. Corundum-graphite sub
merged nozzles may be manufactured with a slag belt and
without one. The nozzle slag belt material contains more
than 68 wt.% ZrO
and more than 15 wt.% C, it has an ap
parent density of not less than 3.45 g/cm
, and open porosity
not more than 18%. One corundum-graphite nozzle replaced
4 – 8 quartz nozzles during pouring of manganese steel types
22GYu and 09G2 .
Compared with corundum-graphite material a higher re
sistance is exhibited by zirconia-graphite material , and
therefore it provides the slag belt of a submerged nozzle. Zir
conia-graphite material is a composite material. Particles of
zirconium oxide and graphite are bonded with each other by
coke residue of phenol formaldehyde resin (glassy carbon).
Zirconia-graphite material is similar with respect to proper-
ties to corundum-graphite and periclase graphite refractories.
The mechanical strength of zirconia-graphite material is
an important characteristic, which affects its operational
properties, such as thermal shock resistance and slag resis-
tance. Primarily composition affects the ultimate strength in
bending, i.e., the ratio of zirconium dioxide and graphite, and
presence of additives. Data for the strength of zirco-
nia-graphite material is presented in different publications.
One of the first corundum-graphite submerged nozzles
with a zirconia-graphite insert was described by Japanese re
searchers . The graphite content in zirconia-graphite mate
rial reached 30 wt.%, and subsequently the graphite content
was reduced to 10 – 15 wt.%. The composition and proper
Refractories and Industrial Ceramics Vol. 54, No. 5, January, 2014
1083-4877/14/05405-0388 © 2014 Springer Science+Business Media New York
Pervoural’sk Dinas Plant, Pervoural’sk, Sverdlov Region, Russia.
GAOU VPO, Ural Federal University, Ekaterinburg, Russia.
TABLE 1. Vessel Material Composition and Properties
Chemical composition, wt.%:
CaO 4 2
Apparent density, g/cm
Open porosity, % 16.0 15.0
Ultimate strength in bending, MPa 10.0 6.0
Elasticity modulus, 10
MPa 0.5 – 0.7 0.2 – 0.3