METHOD OF MANUFACTURE OF BANDAGES FROM HYPEREUTECTOID STEELS Russian patent published in 2003 - IPC

FIELD: heat treatment of ferrous metals; manufacture of bandages for horizontal and vertical rolls of rolling mills. SUBSTANCE: proposed method includes heating of blanks for deformation performed in continuous furnace for at least 8 hours followed by temperature limitations in furnace zones: at charge window not higher than 600 C for 2 hours; continuous zone 700-800 C for at least 2 hours; welding zone 1180-1200 C for at least 3 hours and soaking zone or discharge zone 1180-1200 C for at least an hour; after primary deformation in press, blanks are placed in chamber furnace where they are heated to temperature of 1100-1150 C at rate of 2-10 deg/s and are held at this temperature for at least 3 hours; after repeated deformation in press and rolling in stands, bandages thus obtained are subjected to isothermal holding in half-muffle furnaces at temperature of 630-650 C for at least 5 hours, after which bandages are subjected to additional heating in the same furnaces to temperature of 805-835 C at rate of 2-10 deg/s for quenching; then, bandages are held at this temperature for 3.5-4.5 hours and then they are cooled in quenching medium for 60 s and are held in the air for 60 s, after which they are finally cooled in quenching medium for 50-70 s and self-tempering is performed. Used as quenching medium is water heated to temperature of 40-55 C. Self-tempering of bandages is started from temperature of 460- 480 C and bandages are held to ambient temperature. EFFECT: enhanced strength and operational characteristics. 3 cl, 1 tbl, 1 ex