Magnitogorsk State Technical University named after G. I. Nosov (Magnitogorsk, Russia):

Selivanov V. N., Cand. Eng., Prof., Chair of Metallurgy and Casting Processes
Filippov A. V., Cand. Eng., Scientific Researcher, Chair of Metallurgy and Casting Processes
Dyuldina E. V., Cand. Eng., Associate Prof., Chair of Physical Chemistry and Chemical Technologies
Chernov V. P., Dr. Eng., Prof., Chair of Metallurgy and Casting Processes
E-mail (common): mcm@magtu.ru

The experimental investigation of assimilation of oxide nonmetallic inclusions by mould slag was conducted. These inclusions were floating in the process of continuous casting of 17 melts of low and medium carbon steel from a ladle with a capacity of 365 tons. Four kinds of granulated mould flux powder with different chemical composition have been used to obtained this slag. Chemical composition of slag is practically stable during casting, but it differs significantly from chemical composition of a mould flux. This difference is caused by assimilation by slag of non-metallic inclusions floating from cast steel. Processing of the experimental data on slag chemical composition with use of mathematical model of slag formation provides information on the amount and chemical composition of non-metallic inclusions assimilated by slag. Non-metallic inclusions assimilated by slag contain aluminum, manganese and iron oxides. Content of manganese oxide in these inclusions rises with increase of manganese content in cast steel. It is shown that these non-metallic inclusions were formed in the mould itself as a result of cooling of cast metal down to the liquidus temperature and violation of the equilibrium between the steel deoxidation reactions. The mass of non-metallic inclusions assimilated by slag varies from 0.001 to 0.006% of cast steel mass, increasing with consumption of the mould flux. Transition of floating non-metallic inclusions from metal to slag is limited by the interfacial tension on the boundary between these phases and depends on chemical composition of this mould flux.

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