PURPOSE: To manufacture a supeior high hardness roll at a low cost by forming a composite roll by centrifugal casting using Adamite material as a material for the outer shell part and specified spheroidal graphite cast iron as a material for the core part and by subjecting the composite roll to special heat treatments.
CONSTITUTION: A composite roll is manufactured using Adamite material as a material for the outer shell part and cast iron consisting of, by wt., 2.8W3.6% C, 1.6W2.5% Si, 0.1W0.5% Mn, ≤0.1% P, ≤0.02% S, 0.5W1.5% Ni, 0.1W0.3% Cr, ≤0.5% Mo, 0.02W0.1% Mg and the balance essentially Fe and having 45W55kg/ mm2 tensile strength and 1.0W2.0% elongation as cast as a material for the core part. The outer shell part is subjected to diffusion annealing, spheroidizing annealing and hardening, and the whole roll is tempered. Thus, a high hardness Adamit roll with Hs 60W75 outer shell hardness is obtd.
HASHIMOTO TAKASHI
FUNAKOSHI ATSUSHI
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