Forming pelletising die - and centrifugally casting thin wear resistant alloy inner layer onto thick steel outer annulus

摘要

A die with radial holes through an annular member for outward extrusion is made by centrifugally casting a thin wear-resistant alloy layer onto the inside of a thick outer annulus of low- or medium-alloy steel, and subsequently machining to final dimensions. The outer annulus is pref. itself centrifugally cast, the inner layer is 10 mm thick and the overall thickness is 100 mm. The method eliminates the need to use an inner layer which is thicker than functionally necessary, e.g. by heat-shrinking or dowelling.