US 9,296,027 B2Granted

Method and plant for the energy-efficient production of hot steel strip

AssigneeSiemens Vai Metals Technologies GmbH

InventorsGerald Eckerstorfer, Gerald Hohenbichler, Josef Watzinger

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Abstract

A method is disclosed for continuously or semi-continuously producing hot steel strip which, starting from a slab guided through a slab-guiding device, is rolled in a roughing train having at least four-stands, the method comprising: casting a slab in a die, the slab being reduced to a thickness of between 60 and 95 mm in a liquid core reduction process by the adjoining slab-guiding device, a slab support length measured between the meniscus, i.e., the bath level, of the die and an end of the slab-guiding device facing the roughing train being between 12 m and 15.5 m, and a casting speed ranging from 3.8 to 7 m/min. The disclosed combination of casting parameters may ensure that the crater tip of the slab extends to the vicinity of the end of the slab-guiding device independently of the respective maximum casting speeds which are dependent on the particular grade of material.

Claims23

Dependent claims

A method for the continuous or semicontinuous production of hot steel strip, comprising:

casting a strand by
guiding the strand through a strand-guiding device,
feeding the strand directly to a roughing train,
rolling the strand in the roughing train to form an intermediate strip, and
further rolling the strand in a finishing train to form a finished strip,
wherein the strand-guiding device performs a liquid core reduction (LCR) process to reduce thickness of the strand from an initial thickness in the range 95to 110mm, while the strand has a liquid cross-sectional core, to a strand thickness of between 60 mm and 95 mm,
wherein a strand support length measured between a meniscus and an end of the strand-guiding device facing the roughing train is between 12 m and 15.5 m, and
wherein a casting speed lies in a range of 3.8-7 m/min,
wherein rough-rolling of the strand in the roughing train to form an intermediate strip takes place in at least four reduction stages using at least four roughing stands,
wherein the reduction which takes place in the roughing train takes place within at most 80 seconds;
and
heating the intermediate strip which emerges from the roughing train by an inductive heating arrangement using a cross-field heating method starting from a temperature above 725° C. and ending at a temperature of at least 1100° C.

9 more elements

A plant for performing a method for continuous or semicontinuous production of hot steel strip, comprising:

a die, a strand-guiding device arranged downstream of the die,
a roughing train arranged downstream of and directly after the strand-guiding device,
an inductive heating arrangement arranged downstream of the roughing train, and
a finishing train arranged downstream of the inductive heating arrangement, and
a control device,
wherein said strand-guiding device includes a series of lower guide elements and a series of upper guide elements that is arranged in parallel or converges therewith, and
wherein a receiving slot for receiving the strand that emerges from the die is formed between the two series of guide elements, said receiving slot being tapered at least sectionally by forming different distances between opposing guide elements in a transport direction of the strand such that the thickness of the strand can be reduced,
wherein the internal receiving width of the receiving slot at its entrance region facing the die is between 95 mm and 110 mm,
wherein the receiving slot at its end facing the roughing train has an internal receiving width corresponding to the thickness of the strand of between 60 mm and 95 mm,
wherein a strand support length measured between a meniscus and the end of the receiving slot of the strand-guiding device facing the roughing train is between 12 m and 15.5 m, and
for the control device that controls the casting speed of the strand and maintains the casting speed of the strand in a range of between 3.8-7 m/min,
wherein the roughing train comprises four or five roughing stands, and
wherein the heating arrangement is designed as an inductive cross-field heating furnace by means of which the strand can be heated, starting from a temperature above 725° C., to a temperature of at least 1100° C., and
wherein no cooling device but a thermal cover is provided between the end of the receiving slot or strand-guiding device and an intake region of the roughing train.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/877,876Filed 11 Oct 2011
Priority: EP 1018723212 Oct 2010
Published: US 2013/0192790 A11 Aug 2013
Granted: 29 Mar 2016
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B21B 1/463
For rolling metal immediately subsequent to continuous casting: in a continuous process, i.e. the cast not being cut before rolling
B22D 11/041
Into open-ended moulds: for vertical casting
B22D 11/043
Into open-ended moulds: curved moulds
B22D 11/1206
Accessories for subsequent treating or working cast stock in situ: for plastic shaping of strands