STUDIES OF THE PHYSICO-MECHANICAL PROPERTIES
OF MODIFIERS USED TO TREAT IRON-CARBON ALLOYS
S. M. Voloshchenko,
T. V. Mosina,
K. A. Gogaev,
V. V. Nepomnyashchii,
and M. G. Askerov
Translated from Novye Ogneupory, No. 7, pp. 45 – 48, July, 2012.
Original article submitted February 27, 2012.
Results are presented from the rolling of complex composite modifiers (CCMs) from powdered materials, in
cluding fluxing additives. The main mechanical properties of rolled products made of the CCMs are deter
mined along with the technological parameters that characterize their production and use.
Keywords: complex composite modifiers (CCMs), method of powder-rolling, relative bulk density (RBD).
The goal of the study being discussed here was to ex-
plore the feasibility of obtaining complex composite modifi-
ers (CCMs) by rolling powder-based modifying mixtures
that include up to 60 wt.% hard-to-deform components. The
first task was to obtain sufficiently strong semifinished prod-
ucts (compacts) of the modifier.
The rolling technology that was used made it possible to
introduce fluxing elements into the composition of the modi-
fiers. We rolled 5-mm-high, 30-mm-wide strips with a flux
(fluorite) content of up to 12 wt.%. The volume content of
the ductile components of the modifier was increased and a
metal-matrix composite having sufficient processing strength
without additional heat treatment (sintering) was obtained by
augmenting the modifier with additions of ductile powders
of aluminum, magnesium, and iron and non-ductile powders
of barium silicon, calcium silicon, ferrosilicon, rare-earth
metals (REMs), and fluorspar [1, 2]. The relative bulk den
sity (RBD) of the ductile powders ranged from 0.1 to 0.4,
while the RBD of the non-ductile powders was within the
range 0.45 – 0.65. The quantities of ductile powders added
were equivalent to 30 – 50 vol.% of the modifier.
The compacts were made parallel with the rolling opera
tion. The experiments which were performed showed that the
use of compacts is not always justified because it makes it
necessary to correct the volume of the briquette being
formed in connection with the volume of the liquid metal
which is added. Compacts of square (50 ´ 50 mm
) and cir
cular (20 mm in diameter) cross section were obtained at
pressures of at least 3 ton-f/cm
. The strips of the modifier
were rolled on a mill with horizontal 500-mm-diam. rolls.
Rolling speed was 1.5 m/min. Crushing tests of the compacts
and the strip in double shear were performed on a ‘CERAM
test system” testing machine. Shaft speed was 2 mm/min.
The most important processing characteristic of the modifier
is its strength, since it is not subjected to sintering and must
retain its original form while being transported and intro-
duced into the ladle with liquid metal.
The experiments showed that the forming pressure has
little effect on the strength of the compacts, which is evi
dence of the low degree of compactibility of the CCM pow
ders. The addition of a binder increases the density of the
compacts: the introduction of 7 wt.% of the adhesive KMTs
makes it possible to reduce the pressing pressure by almost
With gravity feed of the powder and the use of a vertical
rolling scheme, the thickness of the strip h
(mm) is related
to the diameter of the rolls by the formula 
where a is the nip angle for capture of the powder by the
rolls, rad; m is the elongation factor, which is equal to the ra
tio of the exit speed of the strip to the rate of feed of the pow
der; z is the degree of compaction, which is equal to the ratio
of the density of the strip to the bulk density of the powder.
The rolling angle can range from 8° to 12° (0.140 – 0.157 rad)
for different powders. Since the material of the modifier is
not ductile for the most part, we take 1 as the value of the
Refractories and Industrial Ceramics Vol. 53, No. 4, November, 2012
1083-4877/12/05304-0229 © 2012 Springer Science+Business Media New York
Institute of Problems of Materials Science of the Ukrainian Na
tional Academy of Sciences (Kiev, Ukraine).