Ishikawajima-harima Heavy Industries Co., Ltd.

Bhp Steel (jla) Pty. Ltd.

Other

John Lysaght (australia) Limited

John Lysaght Limited

Bhp Steel Pty (jla) Ltd

John Lysaght (aus) Ltd.

Ishikawajima-harima Heavy Indistries Limited

William John Folder

Hisahiko Fukase

Walter Blejde

Paul Cassar

Joseph G Herbertson

John Freeman

Stephen Bruce Leabeater

Lloyd Walter Townsend

William J Sinclair

Keith F Pitchford

Twin roll casting method and apparatus in which molten metal is introduced between a pair of chilled rolls (,) via an elongate delivery nozzle (,) to form a casting pool (,) above the nip (,) between the rolls (,). Rolls (,) are rotated to cast a solidified strip (,) delivered downwardly from the nip (,). Delivery nozzle (,) comprises upwardly opening trough having side walls (,), a floor (,) and bottom outlet openings (,). A pair of upright flow barrier walls (,) stand up from floor (,) to define an internal trough channel (,) to receive the incoming flow of molten metal (,). Barrier walls (,) prevent direct flow of the incoming metal to the outlet openings (,).

Casting metal strip

A refractory nozzle 19 for delivery of molten metal to a casting pool 68 of a twin roll caster, and a method and apparatus for casting strip 20 is disclosed in which said nozzle 19 has an elongate open topped trough 61 to receive molten metal, a pair of elongate nozzle chambers 82 extending one along each side of a floor 60 of a trough, metal flow openings 86 for flow of molten metal from the interior of the trough into the nozzle side chambers 82, and nozzle side outlets 64 for flow of molten metal from the side chambers 82 outwardly from the bottom of the delivery nozzle. In a preferred form the nozzle side outlets 64 are elongate slots extending continuously substantially throughout the length of the nozzle and the nozzle side chambers 82 are formed by partition walls 83, 84 disposed within the nozzle to divide off bottom side corner parts of the nozzle from the trough interior whereby the form said side chambers 82 extending along the bottom side corner parts of the nozzle.

Strip casting

Twin roll casting method and apparatus in which molten metal is introduced between a pair of chilled rolls (16) via an elongate delivery nozzle (19) to form a casting pool (68) above the nip (69) between the rolls (16). Rolls (16) are rotated to cast a solidified strip (20) delivered downwardly from the nip (69). Delivery nozzle (19) comprises upwardly opening trough having side walls (62), a floor (63) and bottom outlet openings (64). A pair of upright flow barrier walls (84) stand up from floor (63) to define an internal trough channel (85) to receive the incoming flow of molten metal (65). Barrier walls (84) prevent direct flow of the incoming metal to the outlet openings (64).

Metal strip (20) is cast from casting pool (68) of molten metal supported above nip (69) between chilled casting rolls (16). Molten metal is introduced into the casting pool by nozzle (19) having a trough (61) closed by a bottom floor (63). Metal is supplied to trough (61) in free-falling streams (65) which impinge on floor (63) and fan outwardly across the floor and through nozzle side openings (64) into the casting pool. Streams (65) are staggered longitudinally of the trough with respect to the side openings (64).

A nozzle for delivering molten metal to a casting pool of a twin roll strip caster is formed in two halves and comprises an upwardly opening trough (61) to receive falling supply streams of molten metal and outlet openings (64) at the bottom of the trough. Nozzle end formations (87) define reservoirs (88) to receive separate supply streams of molten metal and flow passages (95) to direct metal from the reservoirs across pool confining end closures of the caster. Each reservoir (88) is separated from trough (61) by an upstanding wall (70) which functions as a weir for metal in the reservoir such that metal can flow over it into the trough when the reservoir is full.

Strip casting apparatus

Method and apparatus for casting metal strip in which molten metal is introduced between a pair of parallel casting rollers (16) via a tundish (18) and metal delivery nozzle (19b). Casting rollers (16) are cooled so that shells solidify on the moving roller surfaces and are brought together at the nip between them to produce a solidified strip product (20) at the roller outlet. A casting pool is established by pouring a first batch of molten metal at a relatively high temperature above the liquidus temperature of molten metal through the delivery nozzle (19b) and is thereafter maintained by pouring through the delivery nozzle (19b) a second batch of molten metal at a relatively lower temperature. The bottom of the tundish (18) is formed with a well (26) to hold the first batch of molten metal and there is heating means (8) to heat the metal in the well (26).

Method and apparatus for casting metal strip in which molten metal is introduced between a pair of parallel casting rollers (16) via a tundish (18) and metal delivery nozzle (19). Casting rollers (16) are cooled so that shells solidify on the moving roller surfaces and are brought together at the nip between them to produce a solidified strip product (20) at the roller outlet. A clean head end of the strip (20) is formed by adjusting the nip of the casting rollers to form a transverse bulge (103) across the width of the strip. The two separate solidified metal shells (105) and defines a line of weakness across the width of the strip. The strip separates at the line of weakness to form a clean head end for the following strip.

Method and apparatus for casting metal strip in which molten metal is introduced between a pair of parallel casting rollers (16) via a tundish (18) and delivery nozzle (19). Casting rollers (16) are cooled so that shells solidify on the moving roller surfaces and are brought together at the nip between them to produce a solidified strip product (20) at the roller outlet. The tundish (18), delivery nozzle (19) and a pair of side closure plates (56) to confine the pool of metal on the casting rollers are separately preheated to working temperature and then rapidly brought into an operative assembly and casting is started before detrimental uneven or localized cooling of the preheated components can develop. To avoid material deterioration and metal flow irregularities due to oxidation on preheating, the delivery nozzle (19) and side closure plates (56) are provided with oxidation retarding coatings, for example in the form of ceramic glazing, or are preheated in an inert atmosphere.

With reference to FIG. 4 , a metal delivery nozzle (19) for delivering molten metal to a nip between a pair of strip casting rollers comprises an upwardly opening inlet trough (61) to receive a series of free falling vertical stream (65) of molten metal and a metal flow passage (62) extending downwardly from the bottom of the inlet trough (61) to a metal flow outlet slot (69). Trough (61) has a side wall surface (64) which slopes downwardly and across the trough to the upper end of the metal flow passage (62). The free falling streams (65) impinge on side wall surface (64) at an acute angle of impingement such that the molten metal tends to adhere to that wall surface and to spread into the form of a sheet (70) flowing down the side wall surface.

A method and apparatus for casting metal strip in which molten metal is introduced between a pair of parallel casting rollers via a metal delivery nozzle disposed above the nip between the rollers, wherein the delivery nozzle comprises an elongate trough to receive molten metal, a nozzle outlet slot extending longitudinally along the bottom of the trough, a baffle structure extending above the slot, and a pair of flow passage means spaced apart laterally of the trough, one to each side of the outlet slot and each providing for flow of molten metal from the trough interior above the baffle structure into the trough interior below the baffle structure.

Method and apparatus for casting molten metal by passing molten metal form a casting pool above the nip of the pair of chilled rollers and thence through the pair of counter rotating chilled rollers, to thus form a thin sheet of solid metal. The molten metal is delivered to the casting pool from a metal delivery nozzle which contains an outlet flow passage at the bottom thereof, below the surface of the casting pool, through which the molten metal passes into the casting pool, which further contains a diffuser therein just above the outward flow passage, and which contains a pool of molten metal sufficiently deep that its surface is above the diffuser. The diffuser had a multiplicity of flow passages (holes) therein through which the molten metal, which is fed to the delivery nozzle, passes and is diffused into the outlet flow passage. An energy absorbing baffle means may be provided above the diffuser.

Growing community of inventors

Kiama Downs, Australia

William John Folder