[go: up one dir, main page]

WO2025040017A1 - Qualité de bord de bande - Google Patents

Qualité de bord de bande Download PDF

Info

Publication number
WO2025040017A1
WO2025040017A1 PCT/CN2024/112743 CN2024112743W WO2025040017A1 WO 2025040017 A1 WO2025040017 A1 WO 2025040017A1 CN 2024112743 W CN2024112743 W CN 2024112743W WO 2025040017 A1 WO2025040017 A1 WO 2025040017A1
Authority
WO
WIPO (PCT)
Prior art keywords
strip
steel strip
side edges
cooling
steel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
PCT/CN2024/112743
Other languages
English (en)
Inventor
Hualong LI
Aihua Chen
Xinyuan Liu
Yujun Liu
Yixin Shi
Ting Zhang
Xianliang Wu
Weigang Chen
Tingting Li
Xia Li
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhangjiagang Zhongmei Ucs Technology Co Ltd
Jiangsu Shagang Group Co Ltd
Jiangsu Shagang Iron and Steel Research Institute Co Ltd
Original Assignee
Zhangjiagang Zhongmei Ucs Technology Co Ltd
Jiangsu Shagang Group Co Ltd
Jiangsu Shagang Iron and Steel Research Institute Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhangjiagang Zhongmei Ucs Technology Co Ltd, Jiangsu Shagang Group Co Ltd, Jiangsu Shagang Iron and Steel Research Institute Co Ltd filed Critical Zhangjiagang Zhongmei Ucs Technology Co Ltd
Publication of WO2025040017A1 publication Critical patent/WO2025040017A1/fr
Pending legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
    • B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/001—Continuous casting of metals, i.e. casting in indefinite lengths of specific alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/1206—Accessories for subsequent treating or working cast stock in situ for plastic shaping of strands
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/12—Accessories for subsequent treating or working cast stock in situ
    • B22D11/124—Accessories for subsequent treating or working cast stock in situ for cooling
    • B22D11/1243—Accessories for subsequent treating or working cast stock in situ for cooling by using cooling grids or cooling plates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/16—Controlling or regulating processes or operations
    • B22D11/22—Controlling or regulating processes or operations for cooling cast stock or mould
    • B22D11/225—Controlling or regulating processes or operations for cooling cast stock or mould for secondary cooling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/02—Hardening articles or materials formed by forging or rolling, with no further heating beyond that required for the formation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/60—Aqueous agents
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/62—Quenching devices
    • C21D1/667—Quenching devices for spray quenching
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/46—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting
    • B21B1/463—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling metal immediately subsequent to continuous casting in a continuous process, i.e. the cast not being cut before rolling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B2261/00—Product parameters
    • B21B2261/20—Temperature
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
    • B21B45/0203—Cooling
    • B21B45/0209—Cooling devices, e.g. using gaseous coolants
    • B21B45/0215—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes
    • B21B45/0218—Cooling devices, e.g. using gaseous coolants using liquid coolants, e.g. for sections, for tubes for strips, sheets, or plates
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2221/00—Treating localised areas of an article
    • C21D2221/02—Edge parts

Definitions

  • the invention relates to making thin steel strip in a twin roll caster and in downstream processing steps that is suitable for end use applications.
  • molten metal typically steel
  • a delivery system to deliver a casting pool supported on casting surfaces of a pair of counter-rotated horizontal casting rolls, which are internally water cooled so that solidified metal shells form on the moving casting roll surfaces.
  • the metal shells are brought together at a nip between them to produce a solidified strip product delivered downwardly from the nip between the casting rolls.
  • nip is used herein to refer to the general region at which the casting rolls are closest together.
  • the molten metal may be poured from a ladle into a smaller vessel or series of smaller vessels from which it flows through a metal delivery nozzle or nozzles located above the nip to form the casting pool of molten metal supported on the casting surfaces of the casting rolls above the nip and extending the length of the nip.
  • the casting pool is usually confined between side plates or side dams held in sliding engagement with end portions of the casting rolls to restrict the casting pool against outflow.
  • the upper surface of the casting pool (generally referred to as the “meniscus” level) is usually above the lower end of the delivery nozzle so that the lower end of the delivery nozzle is immersed within the casting pool.
  • the thin strip exits the nip, passes across a guide table, through a pinch roll stand and then through a hot rolling mill, where the thin strip is reduced to a desired thickness.
  • the hot rolled strip is then cooled to form strip with a required microstructure for end use applications.
  • the cooled strip is then coiled, with a shear cutting the strip periodically upstream of the coiler to form required lengths of strip in each coil.
  • twin roll cast, hot rolled and cooled strip can be used in a range of end use applications.
  • twin roll strip casting steel strip One technical issue for twin roll strip casting steel strip is that the edges of cast and hot rolled strip can be rough and it is necessary to trim these rough edges to be suitable for customers.
  • the edge-trimming step is an additional step in a manufacturing process and adds cost as a consequence.
  • the need to trim rough edges can have a significant impact on product yield. In some instances, the impact on yield is up to 5%.
  • the invention is concerned with addressing the above technical issue.
  • the invention is based on a realization of the applicant that the quality of side edges of steel strip can be improved significantly by controlling the temperatures of side edges, which are typically a much higher temperature than other sections of the steel strip, by cooling, typically quenching, the side edges before entry into a hot rolling mill.
  • the invention includes a twin roll casting method of producing a steel strip that includes:
  • strip is understood herein to comprise (a) opposed surfaces extending along a length and across a width of the strip and (b) opposed side edges on opposite sides of the surfaces extending along the length of the strip.
  • the method may include cooling one or both side edges of the steel strip as close as possible to the hot rolling mill.
  • the method may include cooling one or both side edges of the steel strip between a pinch roll assembly and the hot rolling mill.
  • the method may include cooling one or both side edges of the steel strip at a cooling rate of less than 100 °C /sec.
  • the cooling rate for one or both side edges may be less than 90 °C /sec.
  • the cooling rate for one or both side edges may be at least 20 °C /sec.
  • the cooling rate for one or both side edges may be at least 30 °C /sec.
  • the method may include cooling one or both side edges of the steel strip to a target temperature.
  • the method may include cooling one or both side edges of the steel strip to a target temperature that is at least 150 °C higher than the austenitic transformation temperature of the steel in the strip.
  • the 150 °C is to allow temperature loss through the hot rolling mill.
  • the target temperature is at least 1000 °C.
  • the method may include cooling one or both side edges of the steel strip by at least 40°C.
  • the method may include cooling one or both side edges of the steel strip by at least 50°C.
  • the method may include cooling one or both side edges of the steel strip by at least 80°C.
  • the method may include cooling one or both side edges of the steel strip by at least 40°C and less than 150°C.
  • the method may include cooling one or both side edges of the steel strip by at least 40°C and less than 220°C.
  • the method may include cooling one or both side edges of the steel strip by less than 150°C.
  • the method may include cooling one or both side edges of the steel strip by less than 220°C.
  • the method may include cooling one or both side edges of the steel strip by cooling the side edge or edges with a coolant that contacts the side edge or edges.
  • the coolant is water.
  • the coolant may be any suitable fluid.
  • the method may include cooling one or both side edges of the steel strip with water that contacts the side edge or edges.
  • the method may include cooling one or both side edges with water directed at one or both side edges from water spray nozzles.
  • the steel melt may be any steel composition that can be processed in a twin roll strip casting apparatus.
  • the steel may comprise, by weight, C ⁇ 0.6%, Si ⁇ 0.3%, Mn ⁇ 2.5%, Nb ⁇ 0.1%, P ⁇ 0.03%, S ⁇ 0.0025%, soluble Al ⁇ 0.01%, N ⁇ 0.005%, Cu ⁇ 0.4%, and the remainder iron, impurities and inclusions.
  • impurities means elements in the melt as an inevitable result of steelmaking practices or as a consequence of the feed materials for steelmaking. These tend to be non-metallic elements. Examples of impurities are N, P, S, and H.
  • inclusions means compounds that form during steelmaking. Examples of “inclusions” include AlN and MnS.
  • the method may include superheating the steel melt to a superheat temperature before transferring the melt to the twin roll caster.
  • the method may include hot rolling the steel strip with the steel in the strip in the austenitic region during hot rolling.
  • the austenitic region is steel composition dependent but typically > 820°C.
  • the method may include hot rolling the steel strip with the cast strip entering the hot rolling mill at an average mill entry temperature of 1020-1150°C.
  • the method may include hot rolling the steel strip with the cast strip entering the hot rolling mill at an average mill entry temperature of 1050-1120°C.
  • the method may include hot rolling the steel strip with the cast strip entering the hot rolling mill at an average mill entry temperature of 1050-1080°C.
  • the average mill entry temperature may be no more than 350°C lower than the temperature of the steel strip exiting the twin roll caster.
  • the method may include hot rolling the cast strip with the cast strip entering the hot rolling mill at an average mill entry temperature of 140-160°C higher than an average mill exit temperature.
  • the method may include casting the continuous thin steel strip with a thickness of less than 2.5 mm in the twin roll caster.
  • the method may include casting the continuous thin steel strip with a thickness of less than 2.0 mm in the twin roll caster.
  • the invention also provides an apparatus for producing a steel strip, including:
  • -a twin roll strip caster for forming a continuous thin steel strip of less than 3 mm in thickness from a molten steel melt
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip at a cooling rate of less than 100 °C /sec.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip at a cooling rate of less than 90 °C /sec.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip at a cooling rate of at least 20 °C /sec.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip at a cooling rate of at least 30 °C /sec.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip to a target temperature.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by at least 40°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by at least 50°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by at least 80°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by at least 40°C and less than 220°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by less than 150°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip by less than 220°C.
  • the strip edge cooling station may be configured to cool one or both side edges of the steel strip with a coolant that contacts the strip edge or edges.
  • the coolant is water.
  • the coolant may be any suitable fluid.
  • the strip edge cooling station may be configured to supply water that contacts one or both side edges of the steel strip to cool one or both side edges.
  • the water may be in an atomized form when it contacts the side edge or edges.
  • the strip edge cooling station may comprise water spray nozzles for supplying water to contact one or both side edges of the steel strip to cool one or both side edges.
  • the strip edge cooling station may include a water spray assembly extending across the strip, above and/or below the strip, with the assembly including water spray nozzles for supplying water that contacts one or both side edges of the steel strip to quench the side edge or edges.
  • the apparatus may include a pinch roll stand upstream of the hot rolling mill in the direction of travel of the steel strip.
  • the strip edge cooling station may be located at any suitable location between the pinch roll stand and the hot rolling mill.
  • the strip edge cooling station is located as close as possible to the hot rolling mill.
  • the invention also provides a twin roll strip cast and hot rolled steel strip of less than 3 mm in thickness that does not require side trimming produced by the above-described method.
  • the twin roll strip cast and hot rolled steel strip produced by the method may comprise an at least substantially uniform microstructure across a width and along a length of the as-cast and as-hot rolled strip.
  • substantially uniform in the context of microstructure is understood herein to mean that at least 80%, typically at least 90%, of the strip has the same microstructure.
  • the twin roll strip cast and hot rolled steel strip produced by the method may comprise an at least substantially uniform yield stress across the width and along the length of the as-cast and as-hot rolled strip.
  • the invention also provides a twin roll strip cast and hot rolled steel strip of less than 3 mm in thickness that does not require side trimming produced by the above-described apparatus.
  • the invention also provides a twin roll strip cast and hot rolled steel strip comprising at least one side edge that, in the cast and hot rolled form, does not require side trimming.
  • the strip comprises (a) opposed surfaces extending along a length and across a width of the strip and (b) opposed side edges on opposite sides of the surfaces of the strip extending along the length of the strip.
  • the invention also comprises a twin roll strip cast and hot rolled steel strip comprising an at least substantially uniform microstructure across a width and along a length of the as-cast and as-hot rolled strip.
  • substantially uniform in the context of microstructure is understood herein to mean that at least 80%, typically at least 90%, of the strip has the same microstructure.
  • the invention also provides a twin roll strip cast and hot rolled steel strip comprising an at least substantially uniform yield stress across the width and along the length of the as-cast and as-hot rolled strip.
  • the thickness of the twin roll strip cast and hot rolled steel strip may be less than 3 mm.
  • the thickness of the twin roll strip cast and hot rolled steel strip may be less than 2.5 mm.
  • the steel strip may have any suitable microstructure.
  • Figure 1 is a diagrammatical side view of an embodiment of a twin roll casting apparatus of the invention for producing thin steel strip
  • Figure 3 is a partial diagrammatical side view of the exit end of the twin roll casting apparatus of Figure 1;
  • Figures 5 (a) and (b) are two drawings of one surface of sections of steel strip produced in a twin roll strip casting apparatus in accordance with the invention, with the Figures being top views showing side edges of the sections; and
  • an embodiment of a twin roll strip casting method is not the only embodiment of the method of the invention for producing an embodiment of a thin steel strip of the invention, with the strip comprising (a) opposed surfaces extending along a length and across a width of the strip and (b) opposed side edges on opposite sides of the surfaces of the strip extending along the length of the strip.
  • twin roll casting apparatus is not the only embodiment of the twin roll caster of the invention for producing an embodiment of a thin steel strip of the invention.
  • a twin roll caster of a twin roll casting apparatus comprises a main machine frame 10 that stands up from the factory floor and supports a pair of counter-rotatable casting rolls 12 mounted in a module in a roll cassette 11.
  • the casting rolls 12 are mounted in the roll cassette 11 for ease of operation and movement as described below.
  • the roll cassette 11 facilitates rapid movement of the casting rolls 12 ready for casting from a setup position into an operative casting position as a unit in the caster, and ready removal of the casting rolls 12 from the casting position when the casting rolls 12 are to be replaced.
  • the twin roll caster includes the pair of counter-rotatable casting rolls 12 having casting surfaces 12A laterally positioned to form a nip 18 there between.
  • Molten metal more particularly molten steel described further below, is supplied from a ladle 13 through a metal delivery system to a metal delivery nozzle 17 (core nozzle) positioned between the casting rolls 12 above the nip 18.
  • Molten steel thus delivered forms a casting pool 19 of molten steel above the nip 18 supported on the casting surfaces 12A of the casting rolls 12. This casting pool 19 is confined in the casting area at the ends of the casting rolls 12 by a pair of side closure plates, or side dams 20.
  • the upper surface of the casting pool 19 (generally referred to as the "meniscus" level) may rise above the lower end of the delivery nozzle 17 so that the lower end of the delivery nozzle 17 is immersed within the casting pool 19.
  • the casting area includes the addition of a protective atmosphere above the casting pool 19 to inhibit oxidation of the molten steel in the casting area.
  • the ladle 13 typically is of a conventional construction supported on a rotating turret 42. For steel delivery, the ladle 13 is positioned over a movable tundish 14 in the casting position to fill the tundish 14 with molten steel.
  • the movable tundish 14 may be positioned on a tundish car 66 capable of transferring the tundish 14 from a heating station (not shown) , where the tundish 14 is heated to near a casting temperature, to the casting position.
  • the movable tundish 14 may be fitted with a slide gate 25, actuable by a servo mechanism, to allow molten steel to flow from the tundish 14 through the slide gate 25, and then through a refractory outlet shroud 15 to a transition piece or distributor 16 in the casting position. From the distributor 16, the molten steel flows to the delivery nozzle 17 positioned between the casting rolls 12 above the nip 18.
  • the side dams 20 may be made from a refractory material such as zirconia graphite, graphite alumina, boron nitride, boron nitride-zirconia, or other suitable composites.
  • the side dams 20 have a face surface capable of physical contact with the casting rolls 12 and molten steel in the casting pool 19.
  • the side dams 20 are mounted in side dam holders (not shown) , which are movable by side dam actuators (not shown) , such as a hydraulic or pneumatic cylinder, servo mechanism, or other actuator to bring the side dams 20 into engagement with the ends of the casting rolls 12. Additionally, the side dam actuators are capable of positioning the side dams 20 during casting.
  • the side dams 20 form end closures for the molten pool of molten steel on the casting rolls 12 during the casting operation.
  • Figure 1 shows the twin roll caster producing the cast thin strip 21, with the cast strip moving initially downwardly and then looping upwardly to a guide table 30 through a hot box that contains a controlled, protective atmosphere, for example containing nitrogen, to minimize strop oxidation, and move across a guide table 30 to a pinch roll stand 31, comprising pinch rolls 31A.
  • the guide table 30, the hot box, and the pinch roll stand 31 form part of the apparatus.
  • the casting rolls 12 are internally water cooled as described below so that as the casting rolls 12 are counter-rotated, shells solidify on the casting surfaces 12A, as the casting surfaces 12A move into contact with and through the casting pool 19 with each revolution of the casting rolls 12.
  • the shells are brought close together at the nip 18 between the casting rolls 12 to produce a cast thin strip product 21 delivered downwardly from the nip 18.
  • the cast thin strip 21 is formed from the shells at the nip 18 between the casting rolls 12 and delivered downwardly and moved downstream.
  • the cast thin strip 21 Upon exiting the pinch roll stand 31, the cast thin strip 21 passes through a strip edge cooling station 40 of the apparatus that cools the side edges of the strip by at least 40°Cand less than 220°C, as described further below.
  • the cast thin strip 21 passes through a hot rolling mill 32 of the apparatus.
  • the hot rolling mill 32 comprises a pair of work rolls 32A, and backup rolls 32B, forming a gap capable of hot rolling the cast thin strip 21 delivered from the casting rolls 12, where the cast thin strip 21 is hot rolled to reduce the strip to a desired thickness, improve the strip surface, and improve the strip flatness.
  • the work rolls 32A have work surfaces relating to the desired strip profile across the work rolls 32A.
  • the steel strip enters the hot rolling mill 32 at an average mill entry temperature of 1020-1150°Cand leaves the hot rolling mill at an average mill exit temperature of 140-160°C lower than the average mill entry temperature.
  • the strip edge cooling station 40 may be located at any suitable location between the pinch rolls 31A and the hot rolling mill 32.
  • the strip edge cooling station 40 is located as close as possible to the hot rolling mill 32.
  • the strip edge cooling station 40 may be any suitable construction.
  • strip edge cooling station 40 for any given plant.
  • the strip edge cooling station 40 may be configured to cool the side edges, typically quench the side edges, with water.
  • the strip edge cooling station 40 comprises an assembly of (a) an elongate water pipe 46, with a water inlet 52 at one end and a closed end at the other end, and (b) a plurality of water spray nozzles 48 along the length of the pipe 46.
  • the assembly is positioned so that the water pipe 46 extends across and beyond the width of the cast thin strip 21, with the spray nozzles 48 being oriented to direct water sprays 50 (i.e. in the form of atomized water) towards the side edges of the strip 21 to cool the side edges to a target temperature.
  • water sprays 50 i.e. in the form of atomized water
  • the spray nozzles 48 include flow rate control valves (not shown) that can be selectively opened and closed to direct water sprays 50 selectively to accommodate different width strips.
  • the only valves that are open are the valves of spray nozzles 48 that face the side edges of the cast thin strip 21.
  • the valves of the remaining spray nozzles 48 are closed.
  • the valves of spray nozzles 48 that face the side edges of the cast thin strip 21 may be selectively opened and closed as required so that a predetermined flow rate of water (in a spray) contacts the side edges of the cast thin strip 21. Therefore, the assembly provides flexibility in terms of (a) the sections of the cast strip 21 that are cooled so that the side edges of different width strips can be cooled and (b) the extent to which the side edges are cooled.
  • the strip edge cooling station 40 also comprises a water delivery system 54 for delivering a required flow rate of water to the spray nozzles 48 to achieve a target side edge cooling rate to cool the side edges of the cast thin strip 21 to a target temperature.
  • the invention is not confined to the use of water as a coolant to be delivered via the spray nozzles 48.
  • the invention extends to the use of any suitable coolant.
  • water is delivered by the selected spray nozzles 48 directed to the side edges of the cast thin strip 21 as the strip moves from the pinch roll stand 31 to the hot rolling mill 32.
  • the spray nozzles atomize water to generate a spray that contacts and cools the strip edges.
  • spray nozzles 48 atomize coolant to generate a spray
  • any other coolant discharge port may be employed in any embodiment in lieu of spray nozzles.
  • coolant discharge ports may discharge a non-atomized flow of coolant.
  • the strip leaves the nip at temperatures of the order of 1400°C and greater.
  • the steel strip is cast downwardly into the enclosure 27 supporting a protective atmosphere immediately beneath the casting rolls in the casting position.
  • the first pinch roll stand 31, the strip edge cooling station 40, and the hot rolling mill 32 are also within the enclosure 27, and the protective atmosphere reduces oxidation and scaling of the strip as the strip moves through these unit operations.
  • the hot rolled thin strip passes into a cooling station 97 of the apparatus where the strip is cooled by water that is delivered by spray nozzles 90 of a plurality of rows of water spray assemblies extending across a run-out table 33 of the apparatus as the strip moves over the run-out table 33 in the cooling station 97.
  • spray nozzles atomize coolant to generate a spray
  • any other coolant discharge port may be employed in any embodiment in lieu of spray nozzles.
  • other types of coolant discharge ports may discharge a non-atomized flow of coolant.
  • the cooling station 97 cools the hot rolled thin strip to any suitable temperature having regard to the steel composition and the microstructure required for end-use applications for the steel strip.
  • the cooled hot rolled cast thin strip 21 then passes through a second pinch roll stand 91 of the apparatus having a pair of rollers 91A that provide tension to the cast thin strip 21 during the shear cut.
  • cooling station 97 extends along the path 99 of the strip between the hot rolling mill 32 and the second pinch roll stand 91 with multiple spray nozzles 90 in the multiple rows of water spray assemblies arranged there between.
  • the rows of spray nozzles 90 extend substantially across the strip width or the cooling station width in a widthwise arrangement and are spaced apart along the length of the cooling station 97.
  • the cooled hot rolled cast thin strip 21 is coiled in a coiler 92 of the apparatus, with a shear at a shear station 98 cutting the strip periodically upstream of the coiler to form required length of strip for each coil.
  • a twin roll caster and method are suitable for producing steel strip less than 3 mm, typically less than 2.5 mm, in thickness from a molten steel melt comprising by weight, C ⁇ 0.6%, Si ⁇ 0.3%, Mn ⁇ 2.5%, Nb ⁇ 0.1%, P ⁇ 0.03%, S ⁇ 0.0025%, soluble Al ⁇ 0.01%, N ⁇ 0.005%, Cu ⁇ 0.4%and the remainder iron, impurities and inclusions.
  • impurities means elements in the melt as an inevitable result of steelmaking practices or as a consequence of the feed materials for steelmaking. These tend to be non-metallic elements. Examples of impurities are N, P, S, and H.
  • inclusions means compounds that form during steelmaking. Examples of “inclusions” include AlN and MnS.
  • the purpose of the strip edge cooling station 40 is to lower the temperature of one or both side edges of the steel strip to a target temperature.
  • the invention extends to the use of other coolants.
  • the applicant has found that the quality of side edges of steel strip can be improved significantly by controlling the temperature of the side edges of steel strip before entry into the hot rolling mill 32.
  • the applicant has found that the quality of side edges of steel strip can be improved significantly by controlling the temperature by cooling, typically quenching, the side edges at a selected cooling rate to reach a selected target temperature before entry into the hot rolling mill 32.
  • a skilled person will be able to select an appropriate target temperature and cooling rate to reach a target temperature in any given situation have regard to factors such as the composition of the steel strip, casting temperature, rolling mill requirements, etc., and will be able to set up a plant accordingly.
  • the steel strip be hot rolled in the austenitic region.
  • the target temperature has to be selected to be at least 150 °C higher than the austenitic transformation temperature of the steel because typically there is a temperature loss of 150 °Cas steel strip passes through the hot rolling mill 32.
  • the target temperature is at least 1000 °C.
  • the cooling rate may be less than 100 °C /sec and at least 20 °C /sec.
  • Figures 4 (a) and (b) are drawings of top views of one surface of sections of a cast, hot rolled and cooled steel strip 21 produced in a standard twin roll strip casting apparatus.
  • the standard steel strip 21 in Figures 4 (a) and (b) comprises (a) opposed surfaces generally identified by the numeral 57 (with only one surface shown in the Figures) extending along a length and across a width of the strip and (b) opposed side edges 51 extending along the length of the strip.
  • the standard steel strip 21 in both Figures 4 (a) and (b) has non-uniform side edges 51. Specifically, each side edge 51 is uneven along the length of the steel strip 21.
  • the applicant observed that there are differences in surface texture adjacent the side edges 51 of the steel strip 21 compared to inboard sections of the steel strip 21. The differences in surface texture are indicated by the non-shaded sections 59. With reference to the ruler shown in Figure 4 (b) , the surface texture differences were up to 20mm inboard of the side edges 51. The differences in texture were significant from a product quality perspective.
  • Figures 5 (a) and (b) are drawings of top views of one surface of sections of steel strip 21 produced in a trial of an embodiment of a method of the invention in a twin roll strip casting apparatus in accordance with the invention.
  • the drawings show the sections of steel strip 21 after the cast strip has been hot rolled and cooled.
  • the edges 53 in the drawings are substantially straight edges, particularly when compared to the edges 51 of the standard steel strip 21 shown in Figure 4.
  • the invention is not confined to the use of water as a coolant and sprays as the delivery option.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Continuous Casting (AREA)

Abstract

Un procédé de production de bande d'acier utilisée dans une machine de coulée continue à deux cylindres impliique le laminage à chaud d'une bande d'acier ayant des bords refroidis dans un laminoir à chaud et la réduction de l'épaisseur de bande d'acier, le refroidissement de la bande d'acier dans une station de refroidissement, et l'enroulement de la bande d'acier sur un bobineur.
PCT/CN2024/112743 2023-08-21 2024-08-16 Qualité de bord de bande Pending WO2025040017A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202311054547.5 2023-08-21
CN202311054547.5A CN117300079A (zh) 2023-08-21 2023-08-21 带边缘质量

Publications (1)

Publication Number Publication Date
WO2025040017A1 true WO2025040017A1 (fr) 2025-02-27

Family

ID=89283769

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2024/112743 Pending WO2025040017A1 (fr) 2023-08-21 2024-08-16 Qualité de bord de bande

Country Status (2)

Country Link
CN (1) CN117300079A (fr)
WO (1) WO2025040017A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117300079A (zh) * 2023-08-21 2023-12-29 江苏省沙钢钢铁研究院有限公司 带边缘质量

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489497A (zh) * 2001-02-01 2004-04-14 SMS�����ɷݹ�˾ 影响轧制带材的外形的方法
CN1805803A (zh) * 2003-06-13 2006-07-19 杰富意钢铁株式会社 用于钢板的加速控制冷却系统,其生产的钢板,以及冷却设备
CN101528969A (zh) * 2006-10-30 2009-09-09 蒂森克虏伯钢铁股份公司 由形成复相显微组织的钢制备扁钢产品的方法
KR20120072498A (ko) * 2010-12-24 2012-07-04 주식회사 포스코 쌍롤식 박판 주조 공정에 의한 내크랙성 마르텐사이트계 스테인리스 열연박판 제조용 압연롤 및 그 압연롤을 이용한 내크랙성 마르텐사이트계 스테인리스 열연박판의 제조 방법
CN116511244A (zh) * 2022-01-20 2023-08-01 纽科尔公司 剪切双辊铸带
CN117300079A (zh) * 2023-08-21 2023-12-29 江苏省沙钢钢铁研究院有限公司 带边缘质量

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1489497A (zh) * 2001-02-01 2004-04-14 SMS�����ɷݹ�˾ 影响轧制带材的外形的方法
CN1805803A (zh) * 2003-06-13 2006-07-19 杰富意钢铁株式会社 用于钢板的加速控制冷却系统,其生产的钢板,以及冷却设备
CN101528969A (zh) * 2006-10-30 2009-09-09 蒂森克虏伯钢铁股份公司 由形成复相显微组织的钢制备扁钢产品的方法
KR20120072498A (ko) * 2010-12-24 2012-07-04 주식회사 포스코 쌍롤식 박판 주조 공정에 의한 내크랙성 마르텐사이트계 스테인리스 열연박판 제조용 압연롤 및 그 압연롤을 이용한 내크랙성 마르텐사이트계 스테인리스 열연박판의 제조 방법
CN116511244A (zh) * 2022-01-20 2023-08-01 纽科尔公司 剪切双辊铸带
CN117300079A (zh) * 2023-08-21 2023-12-29 江苏省沙钢钢铁研究院有限公司 带边缘质量

Also Published As

Publication number Publication date
CN117300079A (zh) 2023-12-29

Similar Documents

Publication Publication Date Title
EP1326725B1 (fr) Production de bandes d'acier fines
CN101291750B (zh) 用于制备金属带的工艺及设备
RU2747341C2 (ru) Комбинированная литейно-прокатная установка и способ бесконечного изготовления горячекатаной чистовой полосы
KR100937798B1 (ko) 강 스트립 제조 방법
CN110087801B (zh) 用于在铸轧复合设备中连续制造卷绕的热轧带钢的方法
KR20050042260A (ko) 얇은 슬래브 기술에 기초한 초박형 열간 압연 스트립의제조 공정 및 생산 라인
AU2001291505A1 (en) Production of thin steel strip
WO2020030040A1 (fr) Production d'une bande d'acier coulée entre cylindres et laminée à chaud
NZ329197A (en) Non-contact heat absorbers for strip casting
WO2021136336A1 (fr) Procédé de production d'acier additionné de bore sur la base d'une coulée en bande à double rouleau
WO2025040017A1 (fr) Qualité de bord de bande
WO1995013155A1 (fr) Traitement thermique en ligne d'un feuillard d'acier coule en continu
WO1996001710A1 (fr) Procede de coulee et de laminage d'acier au moyen d'une machine de coulee a deux cylindres
KR20030064761A (ko) 주문에 의한 강 스트립 공급 방법
RU2769114C1 (ru) Комбинированная установка непрерывного литья и прокатки и способ эксплуатации комбинированной установки непрерывного литья и прокатки
WO2001032335A1 (fr) Production d'une bande d'acier mince
US7117925B2 (en) Production of thin steel strip
WO1996001708A1 (fr) Machine de coulee a deux cylindres et laminoir utilisable avec ladite machine
US6209620B1 (en) Method and apparatus for producing coated hot-rolled and cold-rolled strip
KR20090011018A (ko) 강 스트립 제조 방법
CN116511244A (zh) 剪切双辊铸带
WO2021175242A1 (fr) Acier auquel du bore est ajouté et son procédé de production
US20040079512A1 (en) Installation for producing a hot-rolled strip
US9156082B2 (en) Method of continuously casting thin strip

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 24855740

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)