| 摘要 |
PURPOSE:To produce the titled roll having more improved hardness and wear resistance by subjecting the outer shell part of the roll for hot rolling contg. hard metallic carbide to a heat treatment under specific conditions, thereby depositing the NC type metallic carbide having higher hardness on said part. CONSTITUTION:The outer shell part of the composite roll for hot rolling is produced by a low alloy steel contg., by weight, 2.1-2.8% C, <1% Si, <1% Mn, <0.03% P, <0.03% S, <0.8% Ni, 0.9-1.7% Cr, >0.3% Mo, 1-2% V, <1.7% Co, 4.0-5.4% W and <6.4% Nb. Cr depositer Cr7C3 of the hard carbide and the titled roll contg. the outer shell part which has high hardness and excellent wear resistance is thereby produced. Said outer shell part is furthermore quenched at 900-1,100 deg.C to deposite the high hard MC type carbide such as VC, WC, NbC, etc., into a matrix and is successively tempered at 500-800 deg.C to improve the thermal shock resistance of said part. By this method, the titled roll suitable for severe rolling such as the rolling of high alloy steel, etc., and having excellent hardness, strength and wear resistance can be obtd. |
