INTRAFORM MODIFICATION OF CAST IRON. INFLUENCE OF THE COMPOSITION AND CONCENTRATION OF NANOSIZED MODIFIERS ON THE SERVICE CHARACTERISTICS OF GRAY CAST IRON. REPORT 3

Abstract

The paper presents the research of the infl uence of the concentration and composition of nanoscale modifi ers, obtained when using different methods (thermal, plasma-chemical, self-spreading hightemperature synthesis – SHS, mechanochemical and combined with mechano-chemical), on the microstructure and mechanical properties of synthetic grey cast iron in the intraform modifi cation. In addition, in the capacity of nanosized modifi ers dust-like metallurgical waste have been investigated. Classic modifi ers of the Russian production have been used to compare modifying properties. The increase in the Brinell hardness in the range of 13 % has been shown by the samples of cast iron, modifi ed by tungsten and titanium carbides (the SHS method + the mechanochemical one), 10 % – modifi ed by yttrium with zirconium or chromium (the mechanochemical method) and [ά-Fe, TiCx Ny , SiC] (the plasma-chemical method). The increase in the limit of tensile strength by approximately 20 % has been recorded on the samples of cast iron, modifi ed by tungsten and titanium carbides with zirconium (the mechanochemical method). On the samples modifi ed by yttrium with zirconium or chromium (the mechanochemical method) and [α-Fe, TiCx Ny , SiC] (the plasma-chemical method), tensile strength has increased by 8 – 12 %. The concentration of modifi ers, in which the greatest modifying effect has been revealed, has made approximately 0.002 – 0.050 %.