Chuvash State University (Cheboksary, Russia):

I. E. Illarionov, Dr. Eng., Prof, Head of the Chair “Metal science and metallurgical processes, e-mail: tmilp@rambler.ru

State Research Center «CNIITMASH» (Moscow, Russia):
A. S. Kaftannikov, Dr. Eng, Leading Researcher
F. A. Nuraliev, Cand. Eng.

Siberian Federal University (Krasnoyarsk, Germany):
T. R. Gilmanshina, Cand. Eng., Assocoate Prof., e-mail: gtr1977@mail.ru

Currently, more than 40 % of castings are obtained from cast iron by casting into single molds, in which a large proportion of surface defects are in the form of a burn. The aim of the work was the development of a technological sample for determining the value of the coke, which allows reproducing real conditions for the interaction of the surface of the mold with the melt with the use of several non-stick coatings simul taneously. The technological sample is a mold, consisting of a lower and an upper mold. The diameter of the riser installed in the upper half-shape varies depending on the required rate of metal pouring into the mold. The shape of the mold, located in the lower half-mold, is four connected in the center of the beam, with a variable cross-section (25, 50 and 75 mm). Each of the beams is painted with its coating, which allows comparative testing of up to four coatings simultaneously. The work investigated the amount of coke on the surface of the casting obtained without coating and using self-drying coatings, the fillers in which are natural graphite and a mixture of natural and mechanically activated graphites. The mold is made of a coldhardening mixture, the resin is an alphabond. Cast iron SC20 was poured at a temperature of 1 400 °C. The results of the studies showed that on the surface of the casting obtained without the use of coatings, with an increase in the wall thickness from 25 to 75 mm, the amount of fume increases on the vertical and horizontal walls, respectively, mm: from 68.76-128.18 and 76.83-199.23 to 116.66-251.08 and 131.84-408.79. On the surface of castings, there is a defect in the midst. The use of coatings based on graphite GLS-2 (K) and GLS-2A (K) makes it possible to create the most favorable structure. The presence of a defect «heat» on the surface of the castings was not observed. The amount of decay decreased 1.5-2.5 times, depending on the thickness of the casting wall and the quality of the filler.

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