IMPROVING THE MECHANICAL PROPERTIES OF THE IRON PARTS OF ICE BY THE METHOD OF COMPLEX DOPING

Abstract

The article presents the results of long-term studies on the preparation of ligatures for gray and high-strength cast iron, which are used for the casting of key parts of internal combustion engines (ICEs). The main purpose of the study is to extend the life of the components of the ICE by increasing the wear resistance of the main parts (cylinder liners and piston rings). The objectives of the study are to develop a ligature and technology for gray and high-strength pig-iron. The research methods included mathematical modeling by means of regression analysis of Gram matrices formed on the basis of the determined correlation coefficients between the wear resistance of cast iron and its chemical composition, which was checked by Fischer's criterion, as well as practical studies on the casting of pig iron of various brands and bench tests of engines with parts on their basis. The regression equation describing the optimal chemical composition of cast iron is given as I = 8.4 +0.9C- 0.6Si - 3.2Mn - 84.4P - 4.5Ti - 33.8S + 9.3Cr + 0.4Ni - 5 , 9Cu - 1,1V + 24,3Mo. The basis for the development was the analysis of a sufficient number of literary sources related to the dopant properties of different elements when applied in gray and high-strength pig-iron. The main results of the literary search are presented in the corresponding section, where doping with nickel, chromium, molybdenum, vanadium, copper, silicon, titanium and other elements is covered. It was developed and protected by patents of Ukraine No. 25099 and number 25100 highly effective ligatures for pig-iron parts of cylinder-piston group (CPG). The bench tests of hardness resistance of the received pig-iron showed that the formation of sorbitol perlite due to alloying of pig iron in the ladle is an optimal approach that in combination with other measures can significantly improve the quality of the obtained parts. Thus, studies have shown that for super-loaded parts of the cylinder-piston group, the inevitable transition to doped pig-iron is inevitable. For pig-iron for bushings of cylinders of diesel engines of type ЧН 25/34 it is connected with their transition to high-grade fuel, and the work of new forced engines 6CHN 26/34 without doped pig-iron was not possible.