Nucor Corporation

David John Sosinsky

Rama Ballav Mahapatra

Mark Schlichting

Walter N Blejde

Eugene B Pretorius

Marcie M Hinker

Hiroyuki Otsuka

Peter Andrew Woodberry

Mike Schueren

Gary McQuillis

W Kent Cooper

David W McGaughey

Neal Ross

James Leacock McIntosh

Dhiren Panda

Malcolm McDonald

Jerome Jenkins

Koshiro Yamane

Satoshi Terasaki

Dustin E Smith

Brian D White

Rama Ballay Mahapatra

Jacobus Marthinus Andreas Geldenhuis

Daniel Gene Murray

David Wayne Mcgaughey

Methods of billet casting are provided herein. The methods may include the steps of assembling a billet caster with a shroud extending from a tundish to above a mold such that the shroud does not reach molten metal in the mold, delivering molten metal from a ladle into the tundish, delivering molten metal from the tundish through the shroud to the mold, the shroud inhibiting contact between the molten metal and air, casting the molten metal into billets in the mold and cooling the billets below the mold with a coolant spray, and delivering the cooled billet to a runout table to be cut to length.

Shroud for billet casting

Embodiments include a method of making steel with low carbon content which includes preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature ranging from 2912 to 3060 degrees F. and tapping into a ladle the molten steel composition having an oxygen level is about 700 to 1000 ppm. The molten steel composition is then transported to a ladle metallurgy furnace, where the molten steel composition is further heated and one or more elements are added to the molten steel composition. The molten steel composition is then transported from the ladle metallurgy furnace to a vacuum tank degasser. The molten steel composition is then decarburized and one or more elements are added to the molten steel composition at the vacuum tank degasser for deoxidization and desulphurization. The molten steel composition is then transported to a ladle metallurgy furnace to further adjust chemistry and temperature.

Manufacture of low carbon steel

Methods of billet casting

A method of making a steel with low carbon less than 0.035% by weight including steps of preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature as desired for desulfurization at a VTD, tapping open into a ladle the molten steel composition with an oxygen level between about 600 and 1120 ppm, providing slag forming compound to the ladle to form a slag cover over the molten steel composition in the ladle, transporting the molten steel composition in the ladle to a VTD, decarburizing the molten steel composition at the VTD by drawing a vacuum of less than 650 millibars, after decarburizing, adding one or more deoxidizers to the molten steel composition and deoxidizing the molten steel composition, after deoxidizing, adding one or more flux compounds to desulfurize the molten steel composition, and casting the molten steel composition to form a steel with low carbon less than 0.035% by weight.

Low cost making of a low carbon, low sulfur, and low nitrogen steel using conventional steelmaking equipment

A method of making a steel with low carbon less than 0.035% by weight including steps of preparing a heat of molten steel composition in a steelmaking furnace to a tapping temperature as desired for desulfurization at a VTD, tapping open into a ladle the molten steel composition with an oxygen level between about 600 and 1120 ppm, providing slag forming compound to the ladle to form a slag cover over the molten steel composition in the ladle, transporting the molten steel to a VTD, decarburizing the molten steel composition at the VTD by drawing a vacuum of less than 650 millibars, after decarburizing, transporting the molten steel to an LMF and deoxidizing the molten steel composition, after deoxidizing, returning to the VTD to desulfurize and degas the molten steel composition, and casting the molten steel composition to form a steel with low carbon less than 0.035% by weight.

A thin cast steel strip and method of making thereof with improved resistance to microcracking, where the steel strip is produced by continuous casting and contains a carbon content between about 0.010% and about 0.065% by weight, less than 5.0% by weight chromium, at least 70 ppm of total oxygen and between 20 and 70 ppm of free oxygen, and manganese to sulfur ratio greater than about 250. The carbon content in the cast strip may be below about 0.035%, less than 0.005% by weight titanium, and the average manganese to silicon ratio in the strip produced may be greater than 3.5. The carbon content may be less than 0.035%, the casting speed less than 76.68 meters per minute, and the tundish temperature of the molten metal is maintained below 1612&#xb0; C. (2933.7&#xb0; F.).

Thin cast steel strip with reduced microcracking

A metal strip casting apparatus and a method of casting continuous metal strip includes assembling a pair of counter-rotatable casting rolls having casting surfaces positioned laterally forming a nip between for casting, and delivering molten metal through a delivery nozzle disposed above the nip capable to form a casting pool supported on the casting rolls. The delivery nozzle comprises segments each having elongate nozzle body with longitudinally extending side walls, end walls and a bottom part to form an inner trough, a nozzle insert disposed above bottom portions of the inner trough of each segment and supported relative to the nozzle body through which incoming molten metal may be delivered to the inner trough of each segment of the delivery nozzle, and the elongate nozzle body of each segment having passageways in fluid communication with the inner trough and outlet openings capable of discharging molten metal from the nozzle body outwardly into the casting pool.

Casting delivery nozzle with insert

A method for making a thin cast strip with reduced meniscus marks includes assembling a pair of casting rolls laterally positioned to form a nip therebetween, preparing molten steel having a carbon content in the range of 0.01 to 0.3% by weight, a manganese content between 0.1 and 0.8% by weight, a silicon content between 0.05 and 0.5% by weight, a calcium content between 0.0008 and 0.004% by weight, an aluminum content between 2 and 500 ppm by weight, having a free oxygen content below about 50 ppm at 1600&#xb0; C., forming a casting pool of the molten steel supported on casting surfaces of the casting rolls above the nip, and counter-rotating the casting rolls cause thin strip to be casted downwardly from the nip.

Thin cast strip with controlled manganese and low oxygen levels and method for making same

A method of controlling heat flux between the casting pool and the surfaces of the casting roll in a strip steel casting process includes controlling the concentration of nitrogen in the steel melt. The concentration of nitrogen may be controlled to achieve an operational heat transfer to the casting roll. The beat flux to the casting rolls may be controlled by maintaining the sum of partial pressures calculated from the nitrogen and hydrogen concentrations in the casting pool below 1.15 atmospheres. Decreasing the concentration of nitrogen can increase heat flux at the casting rolls.

Casting steel strip

A method of casting steel strip by introducing molten plain carbon steel on casting surfaces at least one casting roll with the molten steel having a free nitrogen content below 120 ppm and a free hydrogen content below about 6.5 ppm measured at atmospheric pressure. The free nitrogen content maybe below about 100 ppm or below about 85 ppm. The free hydrogen content maybe between 1.0 and 6.5 ppm at atmospheric pressure. Novel cast strip of plain carbon steel is produced having a strip thickness less than 5 mm or less than 2 mm by use of the method.

Growing community of inventors

Carmel, IN, United States of America

David John Sosinsky