# US 5,348,203 A · Molten steel pouring nozzle

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- Number: US 5,348,203 A
- Document ID: US5348203A
- Status: Granted
- Kind: A
- Application number: 08/110,088
- Filed: 1993-08-20
- Granted: 1994-09-20
- Earliest claimed: 1992-09-18
- Assignees: Akechi Ceramics Kabushiki Kaisha
- Inventors: Mitsuru Andoh; Noriaki Yamauchi
- Web page: https://patentgrep.com/patent/US5348203A

## CPC

- C04B 35/6303: {Inorganic additives}
- B22D 41/54: characterised by the materials used therefor
- C04B 35/66: Monolithic refractories or refractory mortars, including those whether or not containing clay {(making or repairing of linings F27D1/16)}
- C04B 2111/00887: {Ferrous metallurgy}
- C04B 2235/3217: Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
- C04B 2235/3418: Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
- C04B 2235/3826: Silicon carbides
- C04B 2235/422: Carbon
- C04B 2235/9676: against molten metals such as steel or aluminium
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22)

## Abstract

A molten steel pouring nozzle which comprises: a nozzle body comprising an alumina-graphite refractory, having, along the axis thereof, a bore through which molten steel flows; and an outer refractory layer arranged on an outside portion of the nozzle body so as to be integral with the nozzle body and to be flush with an outer surface thereof, the outer refractory layer being arranged on a portion of the outside portion of the nozzle body, which portion is in contact, when a lower portion of the molten steel pouring nozzle is immersed into molten steel, with the open air without being immersed into the molten steel, and the outer refractory layer consisting essentially of: ______________________________________ alumina (Al.sub.2 O.sub.3) from 40 to 75 wt. %, carbon (C) from 10 to 30 wt. %, silica (SiO.sub.2) from 1 to 30 wt. %, silicon carbide (SiC) from 1 to 20 wt. %, and low-melting glass from 1 to 10 wt. %. ______________________________________

## Claims

### Claim 1

A molten steel pouring nozzle which comprises:
a nozzle body comprising an alumina-graphite refractory, having, along the axis thereof, a bore through which molten steel flows; and
an outer refractory layer arranged on an outside portion of said nozzle body so as to be integral with said nozzle body and to be flush with an outer surface thereof, said outer refractory layer being arranged on a portion of said outside portion of said nozzle body, which portion is in contact, when a lower portion of said molten steel pouring nozzle is immersed into molten steel, with the open air without being immersed into said molten steel, and said outer refractory layer consisting essentially of:
______________________________________ alumina (Al.sub.2 O.sub.3) from 40 to 75 wt. % carbon (C) from 10 to 30 wt. %, silica (SiO.sub.2) from 1 to 30 wt. %, silicon carbide (SiC) from 1 to 20 wt. %, and low-melting glass from 1 to 10 wt. %; and said low-melting glass consisting essentially of: alumina (Al.sub.2 O.sub.3) from 1.5 to wt. %, silica (SiO.sub.2) from 20.0 to 56.0 wt. %, calcium oxide (CaO) from 2.5 to 14.4 wt. %, magnesia (MgO) from 0.05 to 1.60 wt. %, potassium oxide (K.sub.2 O) from 0.25 to 6.40 wt. %, sodium oxide (Na.sub.2 O) from 0.5 to wt. %, boric acid (B.sub.2 O.sub.3) from 2.5 to 24.0 wt. %, and boron carbide (B.sub.4 C) from 20.0 to 50.0 wt. %. ______________________________________

### Claim 2 (depends on 1)

A molten steel pouring nozzle as claimed in claim 1, wherein:
said outer refractory layer of said molten steel pouring nozzle has a thickness within a range of from 1 to 15 mm.

### Claim 3 (depends on 2)

A molten steel pouring nozzle as claimed in claim 2, wherein the outer refractory layer consists essentially of 49.2 wt. % alumina, 19.4 wt. % carbon, 19.8 wt. % silica, 9.8 wt. % silicon carbide and 1.8 wt. % low-melting glass.

### Claim 4 (depends on 2)

A molten steel pouring nozzle as claimed in claim 2, wherein the outer refractory layer consists essentially of 49.2 wt. % alumina, 19.4 wt. % carbon, 18.8 wt. % silica, 8.1 wt. % silicon carbide and 3.7 wt. % low-melting glass.

### Claim 5 (depends on 2)

A molten steel pouring nozzle as claimed in claim 2, wherein the outer refractory layer consists essentially of 49.2 wt. % alumina, 19.4 wt. % carbon, 17.4 wt. % silica, 7.5 wt. % silicon carbide and 6.5 wt. % low-melting glass.

### Claim 6 (depends on 2)

A molten steel pouring nozzle as claimed in claim 2, wherein the outer refractory layer consists essentially of 49.2 wt. % alumina, 19.4 wt. % carbon, 16.0 wt. % silica, 6.1 wt. % silicon carbide and 9.3 wt. % low-melting glass.

### Claim 7 (depends on 2)

A molten steel pouring nozzle as claimed in claim 2, wherein the low-melting glass consists essentially of 3.1 wt. % alumina, 37.1 wt. % silica, 5.5 wt. % calcium oxide, 0.7 wt. % magnesia, 1.3 wt. % potassium oxide, 4.6 wt. % sodium oxide, 14.4 wt. % boric acid and 33.3 wt. % boron carbide.

### Claim 8 (depends on 3)

A molten steel pouring nozzle as claimed in claim 3, wherein the low-melting glass consists essentially of 3.1 wt. % alumina, 37.1 wt. % silica, 5.5 wt. % calcium oxide, 0.7 wt. % magnesia, 1.3 wt. % potassium oxide, 4.6 wt. % sodium oxide, 14.4 wt. % boric acid and 33.3 wt. % boron carbide.

### Claim 9 (depends on 4)

A molten steel pouring nozzle as claimed in claim 4, wherein the low-melting glass consists essentially of 3.1 wt. % alumina, 37.1 wt. % silica, 5.5 wt. % calcium oxide, 0.7 wt. % magnesia, 1.3 wt. % potassium oxide, 4.6 wt. % sodium oxide, 14.4 wt. % boric acid and 33.3 wt. % boron carbide.

### Claim 10 (depends on 5)

A molten steel pouring nozzle as claimed in claim 5, wherein the low-melting glass consists essentially of 3.1 wt. % alumina, 37.1 wt. % silica, 5.5 wt. % calcium oxide, 0.7 wt. % magnesia, 1.3 wt. % potassium oxide, 4.6 wt. % sodium oxide, 14.4 wt. % boric acid and 33.3 wt. % boron carbide.

### Claim 11 (depends on 6)

A molten steel pouring nozzle as claimed in claim 6, wherein the low-melting glass consists essentially of 3.1 wt. % alumina, 37.1 wt. % silica, 5.5 wt. % calcium oxide, 0.7 wt. % magnesia, 1.3 wt. % potassium oxide, 4.6 wt. % sodium oxide, 14.4 wt. % boric acid and 33.3 wt. % boron carbide.