Formation of the structure of sheet blanks during roll casting of metals

Abstract

The physical modeling method was used to study the processes of formation of the structure of sheet blanks during ingotless casting-rolling of metals. At the same time, on the basis of theoretical analysis, the main parameters are determined, with the help of which it is possible to effectively control the processes of crystallization and the formation of the structure of sheet blanks. The studies carried out made it possible to establish the regularities of the influence of hydrodynamic and thermophysical conditions of pouring metal (the speed and nature of metal movement in the inter-roll space, the overheating temperature of the melt and the intensity of heat removal from it) on the processes of its crystallization and structure formation. A transparent organic alloy camphene (C10H16) was used as a modeling medium, which makes it possible to visually study these processes during the ingotless rolling of metals. Due to the transparency of camphene, the transformation of the sheet blank structure at different stages of its formation was clearly studied: the rough primary structure of the crusts solidifying on the rolls, due to their partial deformation in the rolling zone, passes into a fine-grained structure upon exiting it. The dependence of the linear rate of metal pouring on the overheating temperature of the melt and the intensity of heat exchange processes in the roller mold is shown. At the same time, the optimal ranges of values of these parameters are determined, which ensure the stability of the process of roll casting of metals. The results obtained were the basis for the development of practical recommendations for roll casting of real metals, in particular aluminum alloys of various grades. Keywords: roll casting-rolling of metals, roll mold, melt hydrodynamics, overheating temperature, intensity of heat exchange processes, sheet blank, casting speed, structure transformation.