Upgraded Technology of Unkilled and Semikilled Steel Deoxidation
Technology of unkilled and semikilled steel deoxidation with granulated aluminum through the riser was implemented at the open-hearth plant of CJSC "Makeevka Metallurgical Works" in 2007.
The technology ensures reduction of metal consumption for castings production due to reduction of rejects of the first process stage and of additional crops.
Ratio of mass velocity of granulated aluminum to its consumption depending on the steel rimming intensity during ingot body filling was determined for uphill casting at the open-hearth plant.
The technology importance consists in development and realization of processing methods for unkilled and semikilled steel production (carbon content 0.07-0.40%). The ingot, obtained by these methods, has the surface band typical for rimming metal and the internal band typical for semikilled steel. Besides, we determined the rule and standards of changing the aluminum consumption for steel deoxidation to ensure formation of a balanced ingot head.
The obtained data were confirmed by positive results of processing the significant data sets of industrial melts and by metallographic studies.
The technology application for unkilled steel production gives reduction of additional crops on the blooming mill by at least 7 kg/t; for semikilled steel production – about 37 kg/t.
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