Quentin K Robinson

US Patent:

59549890, Sep 21, 1999

Filed:

Mar 20, 1997

Appl. No.:

8/821158

Inventors:

Roger W. Brook - Argyll, GB
Quentin K. Robinson - Pittsburgh PA

Assignee:

Vesuvius Crucible Company - Wilmington DE

International Classification:

B22D 4108

US Classification:

222600

Abstract:

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.

US Patent:

56814992, Oct 28, 1997

Filed:

Oct 26, 1995

Appl. No.:

8/548764

Inventors:

Paul M. Benson - McDonald PA
Duane L. DeBastiani - Pittsburgh PA
Quentin K. Robinson - Pittsburgh PA
David Stephenson - Troon, GB6
Phillipe Dumas - Feignies, FR
Eric Hanse - Dour-Elouges, BE

Assignee:

Vesuvius Crucible Company - Wilmington DE

International Classification:

B22D 4154

US Classification:

222606

Abstract:

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.