JPS5689368A - Production of centrifugally cast roll of high chromium cast iron - Google Patents

Abstract

PURPOSE: To manufacture a double layer centrifugally cast roll free from any shrinkage cavity and cracking occuring in this by performing pouring of molten metal for inside layer part dividedly in plural times.

CONSTITUTION: Molten metal of high choromium cast iron that becomes an outside layer 3 is poured into a metal mold body 11, and molten metal of general cast iron that becomes an inside layer 4 is divided to primary pouring ang secondary pouring, of which the part to become the primary pouring layer 5 out of the inside layer 4 is poured at a high temp. next to the pouring temp. of the outside layer 3. As a result, the primary pouring layer 5 assumes mixed phases of the high chrominum cast iron and the general cast iron. The part to become the secondary pouring layer 6 is poured at about the same temp. as that of the case of a conventional method. In this way, the primary pouring layer 5 is of the mixed phases of the high chromium cast iron and the general cast iron and therefore it becomes low alloy cast iron. When the molten metal of the secondary pouring layer 6 is supplied, this acts as head, and prevents shrinkage cavity from occuring in the primary pouring layer 5. Since the primary pouring layer 5 and the secondary pouring layer 6 which are of mixed phases do not differ so much in components than conventional inside and outside layers, the diffusion phenomenon of Cr and C occurs only slightly between both and this obviates the occurrence of shrinkage cavity defects within the secondary pouring layer 6 as well.

COPYRIGHT: (C)1981,JPO&Japio