# US 5,701,948 A · Casting steel strip > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,701,948 A - Document ID: US5701948A - Status: Granted - Kind: A - Application number: 08/633,949 - Filed: 1996-04-17 - Granted: 1997-12-30 - Earliest claimed: 1995-05-05 - Assignees: Iskikawajima-Harima Heavy Industries Company Limited; BHP Steel (JLA) Pty Ltd. - Inventors: Lazar Strezov; Rama Ballav Mahapatra; Fred de Sylva; Kannappar Mukunthan - Web page: https://patentgrep.com/patent/US5701948A ## CPC - B22D 11/0651: {Casting wheels (B22D11/0682 takes precedence)} - 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 In continuous casting of steel strip, a casting pool of molten metal is supported on moving casting surfaces which are chilled to cause solidification of steel on the casting surfaces. The casting surfaces are textured by provision of parallel groove and ridge formations (11) defining V-shaped grooves (12) and ridges (13) with sharp edges (14). The depth (d) of the texture from ridge peak to groove root is in the range 5 to 50 microns and the pitch (p) between the grooves is in the range 100 to 250 microns. The casting surfaces may be peripheral surfaces of casting rolls of a twin roll caster. ## Claims ### Claim 1 A method of continuously casting steel strip comprising supporting a casting pool of molten steel on one or more chilled casting surfaces and moving the chilled casting surface or surfaces to produce a solidified strip moving away from the casting pool, wherein the or each casting surface is textured by the provision of parallel groove and ridge formations of essentially constant depth and pitch, the depth of the texture from ridge peak to groove root being in the range 5 microns to less than 50 microns, and said pitch being in the range 100 to 250 microns. ### Claim 2 (depends on 1) A method as claimed in claim 1, wherein the casting pool is supported on peripheral casting surfaces of a pair of chilled casting rolls forming a nip between them and rotated in mutually opposite directions to produce the solidified strip such that it moves downwardly from the nip. ### Claim 3 (depends on 2) A method as claimed in claim 2, wherein the groove and ridge formations in each casting surface are defined by a series of parallel annular grooves extending circumferentially around the casting surface and regularly spaced longitudinally of the casting surface at said pitch. ### Claim 4 (depends on 3) A method as claimed in claim 3, wherein the groove and ridge formations in each casting surface are defined by one or more grooves extending helically of the casting surface. ### Claim 5 (depends on 1) A method as claimed in claim 1, wherein the groove formations are of substantially V-shaped cross-section and the ridge formations have sharp circumferential edges. ### Claim 6 (depends on 1) A method as claimed in claim 1, in which the depth of the texture is in the range 15 to 25 microns and said pitch is between 150 and 200 microns. ### Claim 7 (depends on 6) A method as claimed in claim 6, wherein the depth of the texture is about 20 microns and said pitch is about 180 microns. ### Claim 8 (depends on 1) A method as claimed in claim 1, wherein the casting surfaces are chromium surfaces. ### Claim 9 (depends on 1) A method as claimed in claim 1, wherein the molten steel has a sulphur content of at least 0.02%. ### Claim 10 (depends on 9) A method as claimed in claim 9, wherein the molten steel is a silicon/manganese killed steel having a manganese content of not less than 0.20% and a silicon content of not less than 0.10% by weight. ### Claim 11 (depends on 9) A method as claimed in claim 9, wherein the sulphur content of the steel is no less than 0.03% by weight. ### Claim 12 (depends on 11) A method as claimed in claim 11, wherein the sulphur content of the steel is in the range 0.03 to 0.07% by weight. ### Claim 13 (depends on 1) A method as claimed in claim 1, wherein the casting pool is supported on peripheral casting surfaces of a pair of chilled casting rolls forming a nip between them and rotated in mutually opposite directions to produce the solidified strip such that it moves downwardly from the nip. The groove and ridge formations extend circumferentially of the casting surfaces of the rolls, the groove formations are of substantially V-shaped cross-sections and the ridge formations have sharp circumferential edges. ### Claim 14 (depends on 13) A method as claimed in claim 13, wherein the depth of the texture is in the range 15 to 25 microns and said pitch is between 150 and 200 microns. ### Claim 15 (depends on 14) A method as claimed in claim 14, wherein the depth of the texture is about 20 microns and said pitch is about 180 microns. ### Claim 16 (depends on 13) A method as claimed in claim 13, wherein the casting surfaces are chromium surfaces. ### Claim 17 (depends on 13) A method as claimed in claim 13, wherein the molten steel has a sulphur content of at least 0.02%. ### Claim 18 (depends on 16) A method as claimed in claim 16, wherein the molten steel is a silicon/manganese killed steel having a manganese content of not less than 0.02% and a silicon content of not less than 0.10% by weight. ### Claim 19 Apparatus for continuously casting steel strip comprising a pair of casting rolls forming a nip between them, a metal delivery nozzle for delivery of molten steel into the nip between the casting rolls to form a casting pool of molten metal supported on casting roll surfaces immediately above the nip, and roll drive means to drive the casting rolls in counter-rotational directions to produce a solidified steel strip delivered downwardly from the nip, wherein the casting surfaces of the rolls are textured by the provision of circumferentially extending groove and ridge formations of constant depth and pitch, the depth of the texture from ridge peak to groove root being in the range 5 microns to less than 50 microns, and said pitch being in the range 100 to 250 microns. ### Claim 20 (depends on 19) Apparatus as claimed in claim 19, wherein the groove and ridge formations in each casting surface are defined by a series of parallel annular grooves extending circumferentially around the casting surface and regularly spaced longitudinally of the casting surface at said pitch. ### Claim 21 (depends on 19) Apparatus as claimed in claim 19, wherein the groove and ridge formations in each casting surface are defined by one or more grooves extending helically of the casting surface. ### Claim 22 (depends on 19) Apparatus as claimed in claim 19, wherein the grooves of the casting surfaces are of substantially V-shaped cross-section and the ridge formations have sharp circumferential edges. ### Claim 23 (depends on 19) Apparatus as claimed in claim 19, wherein the depth of the texture of the casting surfaces is in the range 15 to 25 microns and said pitch is between 150 and 200 microns. ### Claim 24 (depends on 23) Apparatus as claimed in claim 23, wherein the depth of the texture in the casting surfaces is about 20 microns and said pitch is about 180 microns.