| 摘要 |
PURPOSE: To produce an inexpensive roll for hot rolling, excellent in resistance to wear and fracture loss, for use in the intermediate and the finishing stand at the time of rolling for steel bar, such as round bar and flat bar, and wire rod rolling. CONSTITUTION: This roll is constituted of an outer layer, having a composition consisting of, by weight, 1.7-2.5% C, 0.3-2.0% Si, 0.3-1.5% Mn, 0.2-1.5% Ni, 3-6% Cr, 3-10% Mo, 3-10% W, 3-7% V, 0.5-10% Co, <=0.020% P, <=0.020% S, other inevitable impurities, and the balance Fe and in which the value of M=C%-0.24×V% satisfies 0.3<=M<1.0, and an inner layer made of cast steel or forged steel is metallically joined to the outer layer. This roll is produced by a continuous tinkering padding method. Subsequently, this roll is cooled from a hardening temp. of 1000-1130 deg.C down to 100 deg.C at (300 to 600) deg.C/hr cooling rate and then tempered at 500-550 deg.C several times, by which the hardness of the outer layer is regulated to 85-95HsC.
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