PROCEDURE FOR FABRICATION OF HIGH STRENGTH BANDED FORMING ROLL Russian patent published in 2011 - IPC C21D9/38 

FIELD: metallurgy.

SUBSTANCE: band is set on axle with preliminary heat tightness and thermo-cycled; band surface layer is repeatedly subjected to induction heating. Further, the band is cooled by spraying. Also, high strength Ni-Co-Mo steel of martensite class with carbide-inter-metallic hardening is used as band material. Thermo-cycling is carried out by induction heating a surface layer of the band in each cycle to temperature exceeding temperature of austenite transformation Ac₁ of steel and corresponding to its quenching temperature with successive cooling. Upon the last cycle of heating and cooling the surface layer of band is aged facilitating release of carbide Mo₂C and inter-metallic Fe₂Mo phases in form of high disperse particles of nano metric range from 5 to 10 nm. Also, the band possesses ultimate strength σ_B=2400 MPa and fracture strength K_Ic=120 MPa·m^1/2. Steel of type 25N12M6K10 or 30N12M6K10BV is used as material of a band. Thermo-cycling is performed not less, than five times by heating the surface layer of the band to 1100°C and cooling to room temperature. Upon the last thermo-cycle a band is aged at 500°C.

EFFECT: increased operation resource of roll.

3 cl, 1 ex