Solidification of cast irons

Abstract

Publisher Summary This chapter discusses the solidification of cast irons. Cast irons solidify by two consecutive processes, primary and eutectic phase solidification. Primary phase and eutectic cell nucleation are both heterogeneous nucleation events. Each of these processes occurs by a nucleation and growth process that can be monitored on a cooling curve. The liquid cools at a rate determined primarily by the component design and casting method selected. The structural features of the iron are determined by various particles present in the liquid that act as nucleants for primary and eutectic solidification. The structural features are also determined by the influence of primary phase formation on eutectic formation and the influence of various solute elements on the nucleation as well as growth process together with their interactions with cooling rate and their joint effect on nucleation and growth. The important structural features that result from the solidification events are the primary phase network that forms the matrix, the eutectic cell and the eutectic morphology. The iron properties are determined by the interaction of structural units and any structure modifications resulting from solid state transformations during cooling or heat treatment.