NEW VERTICAL CENTRIFUGAL CASTING PROCESS FOR ROLLING MILLS FOR PROVIDING A HEALTHY, POROSELESS CONNECTION BETWEEN THE FAST STEEL OUTER LAYER AND THE NODULAR CAST IRON

摘要

The present invention relates to a centrifugal casting process with a vertical axis, used in particular for the manufacture of bimetallic or composite rolling mill cylinders, the outer layer of which has multiple eutectics. In general, the traditional casting method is used for cylinders using an external layer with a single eutectic. In the case of an external layer with multiple eutectics, the application of the traditional method, seeking not to pollute the core of carburetor elements, leads to the formation of porosities just before the interface. These porosities frequently lead to serious flaking in service. The new casting process on the contrary makes it possible to eliminate the microporosities by prolonging the cooling of the envelope until the solidification of all the eutectics, but by using a layer of secondary metal whose thickness and temperature of casting allow everything to both provide the necessary and sufficient thermal energy to ensure a good connection of the two layers while avoiding recasting a part of the envelope which would then pollute the heart with carburogenic elements.