NOZZLES CONTAINING LIME AS ANTI-CLOGGING AGENT FOR CASTING ALUMINIUM KILLED STEELS
During continuous casting of aluminium-killed steel it often happens that the nozzle becomes clogged owing to alumina build-up on the inside of the casting hole. The problem is even worse in the case of small moulds when metering nozzles are used. It was decided to alter the chemical composition of the nozzle in an attempt to find a solution to this difficulty. The research has been based on the hypothesis that the formation of low-melting calcium aluminates would favour breakaway of the inclusions from the wall of the casting hole and that these would then be carried away by the stream of steel, thus preventing any clogging. Steels with a sulphur content of over 0.02%, especially if treated with calcium silicide, cannot be cast with these nozzles because clogging is caused by the calcium sulphide, which adheres even to the CaO. A two-layer nozzle was designed with the aim of obtaining a product that associates the wear-resistance properties of the lower ZrO(2) part with the anticlogging characteristics of the upper CaO part.
Bibliographic Reference: EUR 12169 IT (1990) 44 PP., MF, ECU 4 THE OFFICE FOR OFFICIAL PUBLICATIONS OF THE EUROPEAN COMMUNITIES, L-2985 LUXEMBOURG
Record Number: 1989128035800 / Last updated on: 1992-08-10
Original language: IT