The Effect of Heat Treatment on the Stability of Centerline Segregation

The paper deals with the stability of centerline inhomogenity of the continuously cast slabs. The pattern of the centerline segregation was modeled physically by preparing a sandwich structure of steel plates with different levels of carbon and alloying elements. The eligibility of sandwich structured samples for diffusional experiments, i.e. the permeability of the metal-metal boundaries in the samples from diffusional point of view was checked by the comparison of measured and theoretically calculated hardness value for plain carbon steels. Diffusional homogenization experiments were performed and the samples were examined metallographically. Great microstructural difference remains between the core and cover layers alter a long time diffusional homogenization if there is a difference also in the manganese content in the thickness direction of the sandwich structured sample. Manganese has a double role in this process: it reduces the possibility of homogenization of carbon and exaggerates the effect of this slight difference in carbon content during austenite decomposition. (C)2010 Journal of Mechanical Engineering. All rights reserved.