Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 4, pp. 596−600.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
V.N. Esenin, L.I. Denisovich, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 4, pp. 603−607.
AND CORROSION PROTECTION OF METALS
Contact Corrosion of Metals in Aqueous-Glycolic Solutions
with High Content of Water
V. N. Esenin and L. I. Denisovich
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
Received July 2, 2008
Abstract—Corrosion behavior of aluminum, steel, and cast iron in aqueous-glycolic solutions containing 5 to
50 vol % was studied both in the absence of contact and in aluminum–steel, aluminum–cast iron, steel–cast iron,
and aluminum–steel–cast iron contact systems.
This study continues systematic analysis of the contact
corrosion of aluminum, steel, and iron alloys in aqueous
and aqueous-glycolic media in order to determine the in-
ﬂ uence exerted by the composition of an aqueous-organic
solution on the corrosion process. Previously, a study of
the corrosion of these metals in an aqueous medium and
in solutions with content of ethylene glycol (EG) has been
reported . The present communication reports the re-
sults of a study of the corrosion behavior of separate met-
als and aluminum–steel, aluminum–cast iron, steel–cast
iron, and aluminum–steel–cast iron contact systems in
ethylene glycol solutions containing 5–50 vol % water.
The metals and the composition of the aqueous–organic
solution were chosen because these metals are the main
construction materials in modern liquid-cooling systems
and, in particular, internal combustion engines, as well
as in various heat-exchange apparatus, and formulations
based on solutions with high content of water in ethylene
glycol are used as heat-carriers in regions with moderate
and warm climate.
It should be noted that reports devoted to the behavior
of electrochemically dissimilar metals in aqueous-organic
media of various compositions are scarce [2–4], which
makes the present study topical.
Planar 50 × 25 × 3 mm samples of steel 3 [GOST (State
Standard) 380], GH 190 cast iron [VAZ (Volga Automo-
tive Plant) industry standard 52205], and AK6M2 alumi-
num alloy (GOST 1583) were preliminarily polished and
degreased. The electrical contact between metal plates
was provided by an external low-resistance conductor.
The electrode potentials were measured relative to a sil-
ver chloride reference electrode. Ethylene glycol (GOST
19710, extra quality) was used without preliminary pu-
riﬁ cation. The procedures employed in the experiments
were described in .
In the absence of contact between the metallic samples
in 5–50% aqueous-glycolic, the potential of aluminum
remains nearly unchanged in the course of time (–0.48 to
–0.51 V), whereas the potentials of steel and cast iron shift
to more negative values (Fig. 1), which is apparently due
to the gradual dissolution of these metals. In this case,
the higher the water content of a solution, the faster the
shift of the potentials. According to results of gravimet-
ric measurements, the corrosion loss by steel and cast
Fig. 1. Potentials E of the metals in the absence of contact vs.
the testing time τ in aqueous solutions of ethylene glycol. Metal:
) aluminum, (2
) steel, and (3
) cast iron. EG content
) 50, (1
) 30, (1
) 15, and (1