Study of the high strenght steel- nodular iron interphase developed in bimetallic rolls produced by centrifugal casting

摘要

The interphase of bimetallic rolling rolls produced by centrifugal casting using a high speed steel to make the shell and a ductile gray iron for the core was studied. During the manufacturing method and especilly in the course of the slow cooling before demoulding and also during the characteristic long heat treatments always necessary, diffusion phenomena of both, carbon from the core to the shell, and of the shell alloying elements in the oposite direction, take place, giving different micostructures which can reduce the strength of the interphase. A metallographic analisys, using optical and electronic microscopies, was performed and, as a result of it, a highly decarburized region in the vicinity of the core and a very hard and brittle adyacent zone with an important accumulation of different carbides are the most relevant microstructural results.