METHOD FOR PRODUCING MILLING BALLS FROM WHITE ALLOYED CAST IRON Russian patent published in 2001 - IPC

FIELD: metallurgy. SUBSTANCE: method involves performing additional alloying and modifying of cast iron, with alloying for providing predetermined composition being effected in electric furnace during melting. Cast iron is modified with ferrotitanium during pouring into ladle of melt heated to temperature of 1,450-1,470 C. Method further involves forming round cast billet in continuous casting machine; heating it to temperature of 950-1,050 C and rolling to form balls in cross-screw ball-rolling mill; immediately subjecting produced balls having rolling temperature to air quenching by blowing them with air, with following high tempering by heating to temperature of 680-700 C; holding at mentioned temperature for 4-5 hours, with following cooling in air. Cast iron produced contains, wt %: carbon 2.2-3.5; silicon 0.3-0.6; chromium 6.0-12.0; manganese 4.0-6.0; molybdenum 0.5-0.8; boron 0.1-0.3; titanium 0.1-0.3; nickel 0.3-0.6; phosphor 0.02-0.1; sulfur 0.02-0.07; iron the balance. Balls produced may be used as rapidly wearing out parts, for instance milling bodies for ball-type mills. EFFECT: improved strength of balls providing increased wear-resistance, high toughness and plasticity ensuring improved shock-resistance during operation. 1 ex