Vesuvius Crucible Company

Quentin K Robinson

Lawrence John Heaslip

James Derek Dorricott

Eric Hanse

Gilbert Rancoule

Mark K Fishler

Paul M Benson

Dale B Hoggard

Han K Park

Duane L DeBastiani

Phillipe Dumas

David Stephenson

Roger W Brook

A pour tube for use in the continuous casting of a stream of molten metal has a bore comprising a plurality of fluidly connected sections that improve the flow of molten metal through the bore. The sections reduce asymmetric flow of the molten metal stream and the likelihood of precipitates clogging the bore. Each section comprises a converging portion and a diverging portion. The converging portion deflects the stream toward the center of the bore, while the diverging portion diffuses the stream. The sections may comprise a plurality of frusto-conical sections. The cross-sectional areas of the sections may increase, decrease, or remain the same size from an upstream to a downstream position.

Pour tube with improved flow characteristics

A refractory pouring member such as a tundish nozzle or tube and integral plate for use in a slide gate valve or stopper rod valve system in continuous steel casting has selected portions made from an erosion and abrasion resistant refractory composition. The composition comprises: up to 95 wt. % Al.sub.2 O.sub.3 ; up to 15 wt. % C; up to 10 wt. % SiO.sub.2 ; and up to 3 wt. % antioxidant. At least an upper surface of the slide plate is formed from the erosion and abrasion resistant refractory composition to prevent in-service wear of the slide plate and a selected portion of the tube bore is formed of the erosion and abrasion resistant material, preferably extending a distance of about 50 to 300 mm from the top of the slide plate to protect the tube bore from the erosive action within a turbulent flow zone of molten metal which exists when the slide gate valve is in a throttling mode of operation. Pouring members having selected portions made from the erosion and abrasion resistant refractory material are particularly suited for use with tube changers for slide gate valves and for use in stopper rod systems used in the continuous casting of steel.

Erosion and abrasion resistant refractory composition and article made

A dense carbon free surface is provided on a carbon bonded refractory shape which is particularly useful as a pouring tube liner to prevent the formation and build-up of alumina particles which may cause blockage of the tube. The carbon free, dense layer is also hard and erosion resistant making it ideal for use in other applications such as stopper rod noses. The material comprises a refractory mix having a major component of refractory oxides such as alumina and zirconia-mullite. Less than 10 wt. % carbon in the form of graphite and binder is in the mix plus about 2-5 wt. % of a metal such as silicon and an effective mount of sintering aids is also present. The pressed shape is preheated to a temperature of 1000.degree. -1400.degree. C. in air to oxidize the exposed surface of the shape and then to sinter the oxidized surface to form the desired dense, carbon free surface over the entire shape or on selected surface portions thereof.

Method and compositions for making refractory shapes having dense,

A refractory material possessing excellent erosion, thermal shock and oxidation resistance, as well as resistance to oxide build up useful in continuous casting of steel for use in such articles as tundish shrouds, particularly for slagline sleeves, bore liners and upper seating areas in such shrouds, as well as for stopper rod noses. The material consists of the following by weight: (a) carbon, from about 4% to about 50%; (b) one or more members selected from the group consisting of zirconium di-boride and titanium di-boride in an amount of from about 10% to about 90%; and (c) one or more members selected from the group consisting of zirconia, SiAlON, clay, alumina, magnesia, silica, silicon carbide, silicon nitride, boron nitride, mullite and chromia in an mount of from about 10% to about 80%.

Erosion, thermal shock and oxidation resistant refractory compositions

The invention concerns a material for covering the metal contacting surfaces of casting elements such as slide gate valves and casting nozzles and shrouds to resist steel erosion and alumina deposition during the continuous casting of aluminum killed steel. It is comprised of a fused mixture of calcium oxide and zirconia, with a calcium oxide content of between about 20% and about 60% by weight and preferably between about 20% and about 50% by weight, the composition may include a binder producing carbon/carbon bonds by sintering. The material may also include a ceramic bond or may be applied as a fused layer by plasma spraying.

Growing community of inventors

Allegheny County, PA, United States of America

Quentin K Robinson