Influence of Ingot Design on the Homogeneity and Soundness in Large Flat Ingots

Abstract

Influence of shape, dimensions, and hot-topping conditions of 23 to 90 ton large flat ingots on the occurrence of heterogeneities such as channel-type and centerline segregations and centerline loose structure has been made clear to optimize the design of HSLA steel ingots for extra-heavy plates.
Critical values of local solidification rate and local cooling rate for the formation of the channel-type segregation have been evaluated with the aid of heat-transfer calculation on these ingots. A speculative model for the later stage of solidification has also been presented which gives reasonable interpretation of the formation of the centerline heterogeneities characteristic in these large flat ingots.