Patent ID: 8313553
Filing Date: 2012-11-20
Classification: C21C,Y02P

Abstract:
1. A method of making a steel with low carbon less than 0.035% by weight comprising the steps of: (a) preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature as desired for desulfurization at a vacuum tank degasser, (b) tapping open into a ladle the molten steel composition with an oxygen level between about 600 and 1120 ppm, (c) providing slag forming compound to the ladle to form a slag cover over the molten steel composition in the ladle, (d) transporting the molten steel composition in the ladle to a vacuum tank degasser, (e) decarburizing the molten steel composition at the vacuum tank degasser by drawing a vacuum of less than 650 millibars with an oxygen level in the molten steel composition correlated with an amount of carbon desired in the steel composition without adding external oxygen to the molten steel composition, (f) after decarburizing, adding one or more deoxidizers to the molten steel composition and deoxidizing the molten steel composition, (g) after deoxidizing, adding one or more flux compounds to desulfurize the molten steel composition, and (h) casting the molten steel composition to form a steel with low carbon less than 0.035% by weight.