Research on In-Line Reduction Process

Abstract

In-Line reduction process is classified into two methods, one is reducing billet with liquid core and the other is reducing billet after complete solidification. For these two methods, the reduction mechanism and material quality have been investigated. An examination has also been made of shaped reduction with similar size to final shape by later method, and the characteristics of products have been made clear.Main results are as follows:
(1) In reducing process with liquid core, as the liquid in mushy zone which is enriched in some solute atom elements is squeezed by reduction, the center of billets after reduction has the tendency of reverse segregation and this tendency changes with the time after start of reduction. It is cleared that the inner cracks with rolling is prevented by enough reduction.
(2) It is shown that the center line shrinkage completely diminishes and cast structure is refined by the reduction after complete solidification, and the similar quality of reduced billet is obtained to that of the bloomed products. Surface cracks are completely prevented by the application of heating furnace and the choice of casting condition in the continuous casting process.
From the results of the shaped reduction test to reduce square billet to round, dog bone and twin bars by 1 or 2 pass, it is shown that the pass schedule of blooming will be simplified and the mill capacity will be compact.