PURPOSE: To obtain a composite roll having exceptionally strong and tough necks, by casting centrifugally a body shell then casting a molten core metal into a casting mold wherein a bar- or wire-like inoculant coated with an iron sheath is beforehand disposed.
CONSTITUTION: The melt of high alloy grain cast iron or the like is cast into a metallic casting mold 1 coated with prescribed refractories on the inside surface and a body shell (a) of a prescribed thickness is formed by centrifugal casting. When the shell (a) solidifies thoroughly, the mold 1 is perpendicularly erected and a vertical casting mold 4 is constituted together with sand type casting molds 2, 3 for upper and lower necks (c), (c) which are separately prepared. A wire-like inoculant 5 which is coated with an iron sheath and is wound in a coil is beforehand disposed in the molds 2, 3 for the necks (c), (c) along the inside part of the mold. A molten core metal 6 forming a body core (b) and both necks (c), (c) is cast into the mold 4 from the upper part thereof by stationary casting and is charged up into the riser. The three of the shell (a), the core (b) and the necks (c), (c) are thus metallurgically melt-stuck and united to one body, and the composite roll having the high effect of inoculation in the optional core material part and having strength and toughness is formed by casting.
HASHIMOTO TAKASHI
MORIKAWA TAKERU
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