Tolyatti State University, Tolyatti, Russia

D. A. Boldyrev, Dr. Eng., Prof., Dept. of Nanotechnology, Materials Science and Mechanics, e-mail: denis.boldyrev@vaz.ru

Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia
A. A. Nikolaev, Cand. Eng., Head of the Dept. of Automated Electric Drive and Mechatronics, e-mail: aa.nikolaev@magtu.ru

Nosov Magnitogorsk State Technical University, Magnitogorsk, Russia¹ ; Novotroitsk branch of NUST MISIS, Novotroitsk, Russia²
M. V. Kharchenko, Cand. Eng., Associate Prof., Dept. of Mechanics¹, Associate Prof., Dept. of Metallurgical Technologies and Equipment², e-mail: kharchenko.mv@bk.ru
S. P. Nefediev, Cand. Eng., Senior Researcher of the Scientific Innovation Sector¹, Associate Prof., Dept. of Metallurgical Technologies and Equipment², e-mail: sergeynefedyeff@gmail.com

Improving the frictional properties of gray cast iron as a material for brake discs is an urgent task in mechanical engineering. One way to improve the properties of products in this direction is to add various elements to their composition. In this paper, tests were carried out for wear resistance of the manufactured experimental melts of brake discs and samples from them in order to confirm the assumption about the positive effect of sulfur and carbide-forming elements (Mn, Cr, Mo, Ti) on friction properties. Laboratory tests were carried out on the friction machine SMC-2 of samples obtained from manufactured brake discs with different sulfur content. It was determined that with an increase in the sulfur content in cast iron Gh190 from 0.02 % to 0.12 %, the weight wear of the samples decreases by 2 times, and with a sulfur content in cast iron of more than 0.12 %, the wear increases. Bench tests were carried out, in which the friction properties of gray cast irons Gh190 were compared with a standard sulfur value of 0.03 % and with an increased value of 0.12 %. The linear wear of disks with a high sulfur content over the entire series of tests was 30 % than the wear of a disk with a standard sulfur content. At the same time, the linear wear of brake pads paired with discs made of cast iron with a high sulfur content was 12 % less. Also, tests were carried out on the friction machine of samples of brake discs with different contents of sulfur and carbide-forming elements (Mn, Cr, Mo, Ti). It was determined that cast iron with a sulfur content of 0.07 %, molybdenum 0.6 % and titanium 0.2 % suffered 1.8 times less wear than cast iron with a sulfur content of 0.03 %. Varying the content of sulfur and such carbide-forming elements as Mn, Cr made it possible to increase the wear resistance of the samples by a factor of 2. As a result of the research, recommendations were developed for optimizing the material and manufacturing technology of brake discs: for castings of front brake discs VAZ from cast iron Gh190, a change in sulfur content was introduced (0.11-0.13 % instead of 0.01-0, 03 %), which led to a decrease in the intensity of wear of brake discs by 30%, brake pads - by 12 %.
The work was carried out under financial support from the Ministry of Science and Higher Education of the Russian Federation (project No. FZRU-2023-0008).

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