WO1999016564A1 - Tube pour lingotiere de coulee continue d'aciers, notamment d'aciers peritectiques - Google Patents

Tube pour lingotiere de coulee continue d'aciers, notamment d'aciers peritectiques Download PDF

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Publication number
WO1999016564A1
WO1999016564A1 PCT/EP1998/005828 EP9805828W WO9916564A1 WO 1999016564 A1 WO1999016564 A1 WO 1999016564A1 EP 9805828 W EP9805828 W EP 9805828W WO 9916564 A1 WO9916564 A1 WO 9916564A1
Authority
WO
WIPO (PCT)
Prior art keywords
mold tube
heat
mold
insulating layer
longitudinal section
Prior art date
Application number
PCT/EP1998/005828
Other languages
German (de)
English (en)
Inventor
Adrian Stilli
Original Assignee
Concast Standard Ag
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 Concast Standard Ag filed Critical Concast Standard Ag
Priority to EP98948969A priority Critical patent/EP1019208B1/fr
Priority to DE59805207T priority patent/DE59805207D1/de
Priority to AT98948969T priority patent/ATE222150T1/de
Priority to JP2000513688A priority patent/JP4393698B2/ja
Publication of WO1999016564A1 publication Critical patent/WO1999016564A1/fr

Links

Classifications

    • 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
    • B22D11/04—Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds

Definitions

  • the invention relates to a mold tube for a continuous casting mold for the continuous casting of steels, in particular peritectic steels, according to the preamble of claim 1 and a continuous casting mold with the mold tube.
  • the technology of continuous casting in which, by cooling a molten metal on the walls of a mold cavity of a continuous casting mold, forms a continuous shell with a continuously increasing thickness and continuously extrudes a strand from an outlet opening of the continuous casting mold, is known to apply to peritectic steels, for example steels with a Carbon content of 0.1-0.14%, to problems that are particularly evident in the poor surface quality of the strands produced. Such quality defects are undesirable, especially since further processing of the strands often leads to unacceptable quality defects in the subsequent products.
  • phase transition to which peritectic steels are subjected at a temperature just below their solidification temperature and which is associated with a considerable volume contraction.
  • this phase transition takes place during the initial solidification of a strand shell under conditions in which the strand shell which is still formed is of low mechanical stability and, as a result of the phase transition, forms an uneven surface which only lies selectively on the mold cavity wall, with which Result that solidified strands have a porous or cracked layer on the surface.
  • an improved quality of the strand surfaces can be achieved by influencing the initial solidification of the continuous shell in a region of the continuous casting mold comprising the pouring level by reducing the heat dissipation from the steel melt or the continuous shell.
  • This reduction in heat dissipation in the area of initial solidification is usually realized with the aid of continuous casting molds, which are equipped with a heat barrier on the steel-side surface of a longitudinal section of the mold cavity wall.
  • the heat barrier is dimensioned and the longitudinal section dimensioned so that the heat flow density on the one hand
  • the area of the initial solidification is reduced, but on the other hand is large enough in the longitudinal sections adjoining the heat barrier to achieve sufficient growth of the strand shell over the entire running distance of the strand in the mold cavity.
  • JOS 1-170 550 An alternative concept for the formation of a heat barrier is in JOS 1-170 550 using the example of one for the production of slabs from peritectic steel certain plate mold disclosed.
  • the surfaces of the mold cavities on the side of the mold cavity made of copper have bores in a region encompassing the pouring mirror position, which are optionally filled with nickel, stainless steel or a suitable ceramic material.
  • This alternative concept has the disadvantage that - apart from the susceptibility to wear of the fillings of the bores - it cannot be used on pipe molds for small strand formats, for example billet formats, for manufacturing reasons, since the inner sides of the mold pipes are only insufficiently accessible for suitable processing.
  • the invention has for its object to contribute to solving the problems mentioned and for this purpose a mold tube which is equipped with a heat barrier that can be produced using simplified manufacturing technology and is arranged at the mold level and has improved wear resistance, and a corresponding one provided with a mold tube To create continuous casting mold.
  • the mold tube according to the invention has a first longitudinal section including a predetermined pouring mirror position and a second longitudinal section adjoining the first, the first longitudinal section comprising a heat-insulating layer which is dimensioned such that the thermal resistance of the mold tube in the first longitudinal section has a greater value than in the second longitudinal section.
  • the mold is characterized in that the heat-insulating layer fills an area between the outer surface of the mold tube and a distance of at most 75% of the wall thickness of the mold tube, measured from the outer surface of the mold tube.
  • the heat-insulating layer of the mold tube according to the invention is arranged on or near the outside of the mold tube and does not extend to the inner surface of the tube.
  • the mold tube can therefore be produced from a tubular body that can be machined on the outside in order to provide it with the heat-insulating layer. Machining can be carried out using conventional methods, even for tubular bodies that are suitable for the manufacture of mold tubes with a small inner diameter and, due to their geometric dimensions, cannot be machined on the inside, or only at great expense.
  • the heat-insulating layer in the area of the first longitudinal section increases the temperature on the inside of the mold tube. Because the distance of the heat-insulating layer from the inner surface of the mold tube is at least 25% of the wall thickness of the mold tube, the wear of the mold tube during casting operation is due to the thermal and mechanical
  • Material stress in the area of the first longitudinal section is reduced compared to a mold tube which is equipped with a heat-insulating layer of the same thickness on the inside of the mold tube.
  • Temperature distribution which occurs in the casting operation on the inner surface of the mold tube, has to be defined in order to influence the growth of a strand shell in the region of the first longitudinal section in a targeted manner.
  • This degree of freedom is used in the mold according to the invention in order to optimize it with regard to the production of peritectic steel strands.
  • the temperature on the inner surface of the mold tube in the area of the first longitudinal section should be as high as possible during the casting operation.
  • the initial solidification of the molten steel sets in at a distance as far as possible from the pouring level, with the effect that the ferrostatic pressure of the melt increases with that Distance from the pouring level increases, counteracts a local detachment of the strand shell that is being stimulated by the peritectic phase transition from the inner surface of the mold tube and thus favors the formation of a smooth strand surface.
  • the temperature on the inner surface of the mold tube cannot be arbitrarily high during the casting operation, since the material properties of the mold tube have a limiting effect.
  • a mold tube made of copper is known to have an unacceptably short service life after it has been heated to a temperature above a critical temperature of 450 ° C., the so-called softening temperature.
  • the thickness of the heat-insulating layer is therefore dimensioned such that the temperature on the inside of the mold tube in the casting operation does not exceed a predetermined critical temperature T ⁇ .
  • the outer surface of the mold tube is of stepless design at the boundary between the longitudinal sections.
  • This embodiment is particularly suitable for use in molds with water jacket cooling on the outside of the mold tube. Since the water jacket in such molds is usually only a few mm thick and its thickness along the mold tube must be precisely controlled, a stepless design of the transition between the two longitudinal sections enables a particularly simple construction of the water jacket cooling.
  • the heat-insulating layer is embedded in a tubular body made of metal or a metal alloy.
  • a tubular body made of metal or a metal alloy.
  • the heat-insulating layer is made of a metal, for example nickel or chromium. These materials are good on each other in terms of their coefficient of expansion matched so that a nickel or. Chrome layer is characterized by good adhesion and high wear resistance.
  • Mold tube designed with a coolant in such a way that the temperature of the inner surface in the region of the first longitudinal section at most reaches a predetermined critical temperature and is approximately constant in at least one section of the first longitudinal section.
  • the initial solidification of the strand shell can be delayed up to a particularly large distance from the pouring mirror and a particularly smooth strand surface can be achieved after passing through the peritectic phase transition.
  • the thickness d of the heat-insulating layer must increase at least in a section between the pouring mirror position and the second longitudinal section in the direction of the second longitudinal section.
  • FIG. 1A an example of the mold tube according to the invention in side view
  • FIG. 1B a cross section along the line I-1 in FIG. 1A;
  • Fig. 1C a cross section along the line II-II in Fig. 1A;
  • FIG. 2B a longitudinal section as in FIG. 2A, but for a different thickness profile of the heat-insulating layer; 3: curves of the thickness d of a heat-insulating layer according to FIG. 2A as a function of the wall thickness d w of the mold tube for a predetermined wall temperature;
  • FIG. 1A shows an example of the mold tube 10 according to the invention, shown in side view, with a mold cavity 20, a pouring opening 12 and a pull-out opening 13 for a strand (not shown).
  • the direction of strand extraction provided in the casting operation is indicated by an arrow 14.
  • the mold tube 10 has a first longitudinal section 1 and a second longitudinal section 2, the longitudinal section 1 comprising a casting level position h provided in the casting operation and the longitudinal section 2 adjoining the longitudinal section 1 in the strand pull-out direction 14.
  • the mold tube 10 consists of a tube body 15 with a heat-insulating layer 16 in the region of the longitudinal section 1.
  • FIG. 1 B and 1 C show cross sections of the mold tube 10: FIG. 1 B shows a cross section in the plane II marked in FIG. 1A in the region of the longitudinal section 1, FIG. 1 C shows a cross section in the one marked in FIG. 1A Level II-II in the area of the longitudinal section 1.
  • the heat-insulating layer 16 is arranged on the outside 11 of the tubular body 15.
  • the mold cavity 20 has, for example, a square cross section with rounded corners. This selection is arbitrary.
  • the mold tube according to the invention can be equipped with any cross-sectional shapes customary in continuous casting practice.
  • 2A and 2B show longitudinal sections along the line III-III in FIGS.
  • FIG. 1B and 1C identify two different embodiments of the mold tube 10 according to the invention, which differ in the design of the thickness profile of the heat-insulating layer 16 in the longitudinal direction of the mold tube .
  • the heat-insulating layer 16 is embedded in a depression on the outside of the tubular body 15.
  • the outer surface 11 of the mold tube 10 is stepless at the edges of the longitudinal section 1.
  • the tubular body suitably consists of copper or a copper alloy.
  • Metals such as nickel or chromium, which can be applied to the tubular body 15 using conventional methods, for example plating or electrochemical processes, are expediently suitable as materials for the construction of the heat-insulating layer.
  • other materials for example ceramic materials, can also be used for the construction of the heat-insulating layer, provided that they have a lower thermal conductivity than the tubular body 15 and are suitable with regard to their adhesive properties and their wear resistance.
  • the embodiment of the mold tube 10 according to the invention shown in FIG. 2A is characterized in that the heat-insulating layer 16 has an essentially constant thickness in the region between the pouring mirror position h and its edge adjoining the longitudinal section 2, which is denoted by d in FIG. 2A. having.
  • the temperature on the inner surface of the mold tube 10 would be maximum from a point located at the mold level h
  • the temperature profile established on the inner surface 25 of the mold tube 10 can be modified in a targeted manner by a corresponding variation of the thickness of the heat-insulating layer 16 in the strand pull-out direction 14 in order to optimize the strand shell growth.
  • the heat-insulating layer 16 grows in a wedge shape from a thickness d to a thickness b in the region between the pouring mirror position and its edge adjoining the longitudinal section 2.
  • the thicknesses d and b can be selected in relation to the wall thickness d w of the mold tube 10 so that the temperature profile at the
  • the inside 25 of the mold tube 10 is approximately constant in the strand pull-out direction 14 and reaches a predetermined value.
  • the detailed temperature profile is correlated with the strand shell growth on the surface 25.
  • the tubular body 15 is generally designed for use at a temperature below a maximum, critical temperature T ⁇ .
  • the mold tube 10 can be designed for continuous casting of steel in terms of heat technology, provided that the outer surface is cooled by the application of coolant. So that the temperature on the inner surface 25 of the mold tube 10 does not exceed a predetermined critical temperature T ⁇ , the thickness d of the heat-insulating layer 16 at the casting level position h should be according to
  • T s temperature of the steel on the inner surface 25 of the
  • T L temperature of the coolant.
  • ⁇ heat transfer coefficient for the transition between the
  • the ratio d M A ⁇ dw of the mold tube 10 decreases with increasing wall thickness d w .
  • the d MA ⁇ / dw is the greater the smaller f, ie the greater the thermal conductivity ⁇ j of the heat-insulating layer.
  • the parameter range f> 4 is therefore preferred in addition to the condition d M A d w ⁇ 75%.
  • the length of the mold tube 10 is typically 80-100 cm.
  • the length of the length section 1 is preferably in the range 10-15 cm, the pouring mirror position preferably being located in the upper quarter of the length section 1.
  • the heat-insulating layer 16 is always embedded in a recess in the tubular body 15 in such a way that the outer surface 11 of the mold tube 10 is of stepless design.
  • the surfaces 11 and 25 of the mold tube according to the invention could also be provided with coatings made of suitable materials.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Metal Rolling (AREA)
  • Metal Extraction Processes (AREA)

Abstract

L'invention concerne un tube pour lingotière de coulée continue d'aciers, notamment d'aciers péritectiques. Ce tube comporte une première section longitudinale (1) intégrant une position prédéterminée de surface du bain (h), et une deuxième section longitudinale (2) faisant suite à la première. La première section longitudinale (1) comprend une couche calorifuge (16) dont les dimensions sont telles que la résistance à la chaleur du tube de lingotière (10) dans la première section longitudinale (1) est supérieure à celle de la deuxième section longitudinale (2). La couche calorifuge (16) remplit une région allant de la surface extérieure (11) du tube de lingotière (10) à une distance équivalente à 75 % au maximum de l'épaisseur de paroi (dw) du tube de lingotière (10), mesurée à partir de la surface extérieure (11) de ce dernier. Un choix approprié du profil d'épaisseur de la couche calorifuge dans le sens d'extraction du brin (14) permet de réguler un profil de température prédéfini sur la face intérieure du tube de lingotière lors d'une opération de coulée et d'optimiser la croissance d'une croûte solidifiée de barre de coulée continue.
PCT/EP1998/005828 1997-10-01 1998-09-14 Tube pour lingotiere de coulee continue d'aciers, notamment d'aciers peritectiques WO1999016564A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP98948969A EP1019208B1 (fr) 1997-10-01 1998-09-14 Tube pour lingotiere de coulee continue d'aciers, notamment d'aciers peritectiques
DE59805207T DE59805207D1 (de) 1997-10-01 1998-09-14 Kokillenrohr für eine stranggiesskokille zum stranggiessen von stählen, insbesondere peritektischen stählen
AT98948969T ATE222150T1 (de) 1997-10-01 1998-09-14 Kokillenrohr für eine stranggiesskokille zum stranggiessen von stählen, insbesondere peritektischen stählen
JP2000513688A JP4393698B2 (ja) 1997-10-01 1998-09-14 包晶系の鋼を連続鋳造するための連続鋳造鋳型用の管状鋳型

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH2297/97 1997-10-01
CH229797 1997-10-01

Publications (1)

Publication Number Publication Date
WO1999016564A1 true WO1999016564A1 (fr) 1999-04-08

Family

ID=4230492

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP1998/005828 WO1999016564A1 (fr) 1997-10-01 1998-09-14 Tube pour lingotiere de coulee continue d'aciers, notamment d'aciers peritectiques

Country Status (11)

Country Link
EP (1) EP1019208B1 (fr)
JP (1) JP4393698B2 (fr)
AR (1) AR015459A1 (fr)
AT (1) ATE222150T1 (fr)
CZ (1) CZ289354B6 (fr)
DE (1) DE59805207D1 (fr)
ES (1) ES2182361T3 (fr)
RU (1) RU2203158C2 (fr)
TW (1) TW483783B (fr)
WO (1) WO1999016564A1 (fr)
ZA (1) ZA988870B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000029146A1 (fr) * 1998-11-13 2000-05-25 Sms Demag Ag Plaque a lingotieres d'une installation de coulee continue
US11020794B2 (en) 2016-10-19 2021-06-01 Jfe Steel Corporation Continuous casting mold and method for continuously casting steel

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5999294B2 (ja) * 2014-07-24 2016-09-28 Ｊｆｅスチール株式会社 鋼の連続鋳造方法
EP3213838B1 (fr) * 2014-10-28 2021-10-20 JFE Steel Corporation Moule pour coulée continue et procédé de coulée continue pour acier
RU2678556C1 (ru) * 2017-09-18 2019-01-29 Акционерное общество "Первоуральский новотрубный завод" (АО "ПНТЗ") Гильза кристаллизатора для непрерывной разливки сталей
BR102018010463B1 (pt) * 2018-05-23 2021-10-26 Universidade Federal De Minas Gerais - Ufmg Sistema de desmoldagem de peças cerâmicas fabricadas por freeze-casting

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1957332A1 (de) * 1969-11-14 1971-05-19 Kabel Metallwerke Ghh Stranggiesskokille zum Giessen von Metall,insbesondere Stahl
EP0030308A1 (fr) * 1979-11-27 1981-06-17 Concast Holding Ag Moule pour la coulée continue de l'acier
SU904877A1 (ru) * 1980-01-10 1982-02-15 Институт черной металлургии Металлический холодильник дл формировани слитка
JPH01170550A (ja) * 1987-12-24 1989-07-05 Nkk Corp 鋼の連続鋳造用鋳型
JPH01224142A (ja) * 1988-03-03 1989-09-07 Sumitomo Metal Ind Ltd 連続鋳造用鋳型
JPH026038A (ja) * 1988-06-27 1990-01-10 Nkk Corp 鋼の連続鋳造用鋳型
DE3909900A1 (de) * 1989-03-25 1990-10-18 Thyssen Stahl Ag Stranggiesskokille zum giessen von stahlband

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1957332A1 (de) * 1969-11-14 1971-05-19 Kabel Metallwerke Ghh Stranggiesskokille zum Giessen von Metall,insbesondere Stahl
EP0030308A1 (fr) * 1979-11-27 1981-06-17 Concast Holding Ag Moule pour la coulée continue de l'acier
SU904877A1 (ru) * 1980-01-10 1982-02-15 Институт черной металлургии Металлический холодильник дл формировани слитка
JPH01170550A (ja) * 1987-12-24 1989-07-05 Nkk Corp 鋼の連続鋳造用鋳型
JPH01224142A (ja) * 1988-03-03 1989-09-07 Sumitomo Metal Ind Ltd 連続鋳造用鋳型
JPH026038A (ja) * 1988-06-27 1990-01-10 Nkk Corp 鋼の連続鋳造用鋳型
DE3909900A1 (de) * 1989-03-25 1990-10-18 Thyssen Stahl Ag Stranggiesskokille zum giessen von stahlband

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 013, no. 441 (M - 876) 4 October 1989 (1989-10-04) *
PATENT ABSTRACTS OF JAPAN vol. 013, no. 542 (M - 901) 5 December 1989 (1989-12-05) *
PATENT ABSTRACTS OF JAPAN vol. 014, no. 140 (M - 0950) 16 March 1990 (1990-03-16) *
SOVIET INVENTIONS ILLUSTRATED Section Ch Week 8250, Derwent World Patents Index; Class M22, AN 82-08771J, XP002090740 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2000029146A1 (fr) * 1998-11-13 2000-05-25 Sms Demag Ag Plaque a lingotieres d'une installation de coulee continue
DE19852473C5 (de) * 1998-11-13 2005-10-06 Sms Demag Ag Kokillenplatte einer Stranggießanlage
US11020794B2 (en) 2016-10-19 2021-06-01 Jfe Steel Corporation Continuous casting mold and method for continuously casting steel

Also Published As

Publication number Publication date
CZ289354B6 (cs) 2002-01-16
RU2203158C2 (ru) 2003-04-27
EP1019208A1 (fr) 2000-07-19
EP1019208B1 (fr) 2002-08-14
JP2001518394A (ja) 2001-10-16
ZA988870B (en) 1999-04-01
JP4393698B2 (ja) 2010-01-06
ES2182361T3 (es) 2003-03-01
DE59805207D1 (de) 2002-09-19
TW483783B (en) 2002-04-21
AR015459A1 (es) 2001-05-02
ATE222150T1 (de) 2002-08-15
CZ20001187A3 (en) 2001-06-13

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