INTRA-MOLD MODIFICATION OF CAST IRON. THE STUDY OF THE INFLUENCE OF MODIFIERS PRODUCED BY PLASMA CHEMICAL AND SHS METHODS ON SERVICE CHARACTERISTICS OF GREY CAST IRON. REPORT 2

Abstract

Abstract. The studies are devoted to the infl uence of nanopowders produced by plasma chemical method and self-propagating hightemperature synthesis (SHS) on service characteristics of grey cast iron SCh20 at intra-mold modifi cation. Modifi ers (I) in iron matrix of the composition (ά-Fe, TiCxNy , SiC) from natural raw material (titano-magnetite) have been produced by plasma chemical method at the interaction of titano-magnetite powder and methane in the fl ow of hydrogen-nitrogen plasma. Modifi ers of the composition II on conversion to carbides (70 ‒ 80 % WC ÷ 20 ‒ 30 % TiC) with zirconium as metal-protector have been produced by SHS method combined with mechanochemical method. The usage of modifi er I in the amount of 0,002 % increases Brinell hardness by 9,8 %, ultimate tensile strength – by 11,9 %, relative wear resistance – by 21 %, corrosion resistance in hydro-chloric acid – by 12,3 % as compared with check (unmodifi ed) sample of cast iron. The usage of modifi er II in the amount of 0,038 % increases Brinell hardness by 13,1 %, ultimate tensile strength – by 19,8 %, relative wear resistance – by 69 %, corrosion resistance in hydrochloric acid – by 28 %.