U.S. patent application number 10/534942 was filed with the patent office on 2006-08-31 for continuous casting mold for casting molten metals, particularly steel materials, at high casting rates to form polygonal billet, bloom, and preliminary section castings and the like.
Invention is credited to Josef Kockentiedt, Dirk Letzel, Uwe Plociennik, Adolf Gustav Zajber.
Application Number | 20060191661 10/534942 |
Document ID | / |
Family ID | 36930992 |
Filed Date | 2006-08-31 |
United States Patent
Application |
20060191661 |
Kind Code |
A1 |
Zajber; Adolf Gustav ; et
al. |
August 31, 2006 |
Continuous casting mold for casting molten metals, particularly
steel materials, at high casting rates to form polygonal billet,
bloom, and preliminary section castings and the like
Abstract
The invention relates to a continuous casting mold for casting
molten metals, particularly steel materials, at high casting rates
to form polygonal billet, bloom, and preliminary section castings
(1) and the like. Said mold is comprised of a tubular mold (2) made
of copper or of copper alloys whose entry cross-section (3) on the
pouring-in side (4) has both a cross-section (5), which is enlarged
compared to the exit cross-section (6) on the casting exit side
(7), and corner radii (8). The continuous casting mold can be
improved in a technologically process-oriented manner with regard
to requirements concerning the cooling processes. To this end, the
inner geometric cross-sectional shape (9) and the associated
dimensions (10) are provided so that they are analogous to the
amount of solidification heat, which is capable of being locally
dissipated, at a chosen casting rate and are analogous to the
extension of the tubular mold (2).
Inventors: |
Zajber; Adolf Gustav;
(Langenfeld, DE) ; Letzel; Dirk; (Ratingen,
DE) ; Kockentiedt; Josef; (Duisburg, DE) ;
Plociennik; Uwe; (Ratingen, DE) |
Correspondence
Address: |
FRIEDRICH KUEFFNER
317 MADISON AVENUE, SUITE 910
NEW YORK
NY
10017
US
|
Family ID: |
36930992 |
Appl. No.: |
10/534942 |
Filed: |
October 1, 2003 |
PCT Filed: |
October 1, 2003 |
PCT NO: |
PCT/EP03/10861 |
371 Date: |
February 6, 2006 |
Current U.S.
Class: |
164/418 ;
164/459 |
Current CPC
Class: |
B22D 11/041 20130101;
B22D 11/055 20130101 |
Class at
Publication: |
164/418 ;
164/459 |
International
Class: |
B22D 11/00 20060101
B22D011/00 |
Claims
1. A continuous casting mold for casting molten metals,
particularly molten steel materials, at high casting rates to form
polygonal billet, bloom, and preliminary section castings and the
like; comprising a tubular mold made of copper or of copper alloys
whose entry cross-section on the pouring-in side has a
cross-section which is enlarged compared to the exit cross-section
on the casting exit side and corner radii, wherein the inner
geometrical cross-section form and the associated measurements are
designed analogous to the locally deducible quantity of the
solidification heat for the continuous casting according to the
progression of the temperature diagram across the mold height,
starting with the cross-section enlargement on the pouring-in side
opposite the exit cross-section on the casting exit side, wherein
on the pouring-in side in the area of the casting mirror a section
of great conicity, and immediately adjacent a section of greater
conicity, and under the section of greater conicity, a continuously
variable conicity according to the casting shell growth and the
contraction of the continuous casting until the exit cross-section
is successively arranged such that the wall volume is reduced
according to the dissipated heat quantity per time unit and diagram
across the mold height by enlarging the exterior surface of the
tubular mold by means of notches or the like and by reducing the
wall thickness in at least separate height ranges analogous to the
thermal expansion of the mold.
2. The continuous casting mold according to claim 1, wherein the
exterior form is reduced at least in separate height ranges of the
tubular mold analogous to the thermal expansion of the mold.
3. The continuous casting mold according to claim 1, wherein the
tubular mold is designed with regard to its geometrical
cross-section forms based on the respective steel grade.
4. The continuous casting mold according to claim 1, wherein
starting at the entry cross-section a centric, approximately
parabola-shaped recess is provided for each cross-section side.
5. The continuous casting mold according to claim 4, wherein the
approximately parabola-shaped recess diminishes in the direction
towards the casting exit side.
6. The continuous casting mold according to claim 4, wherein the
length of the approximately parabola-shaped recess extends
approximately into half the tubular mold height.
7. The continuous casting mold according to claim 4, wherein the
length of the approximately parabola-shaped recess is adapted to
the contraction measure at the height of the respective broadside
and/or edge of the mold cross-section.
8. The continuous casting mold according to claim 1, wherein in the
area of a corner radius in the cross-section plane of the entry
cross-section one adjoining, circumferentially extending surface
each extends downwards to the casting mirror which connects to an
analogous identical counter surface starting at the casting mirror
until the transition into the geometrical cross-section form.
Description
[0001] The invention relates to a continuous casting mold for
casting molten metals, particularly molten steel materials, at high
casting rates to form polygonal billet, bloom, and preliminary
section castings and the like. Said mold is comprised of a tubular
mold made of copper whose entry cross-section on the pouring-in
side has a cross-section which is enlarged compared to the exit
cross-section on the casting exit side and corner radii.
[0002] A vastly identical continuous casting mold is known from EP
0 498 296 B2. The underlying objective of this casting mold is to
achieve a measurable cooling along the entire circumference of the
casting oxide layer within the tubular mold by deforming the
casting cross-section, in order to improve the casting quality on
the one hand, and increase the casting rate on the other.
Furthermore, differences in the casting rate during the operation
should be permissible without damaging the castings. This objective
is met in the known invention by means of cross-section
enlargements in the shape of bulgings which continuously decrease
in size. There should be at least three such bulgings across the
circumference for round castings.
[0003] Such a design is not limited to round castings; however, it
cannot simply determine the cooling conditions of the continuous
casting, in particular with regard to the surface quality, the
near-edge texture structure and the throughput rate of a billet
mold.
[0004] The performance of such billet molds is also directed
towards achieving high surface qualities together with high casting
rates.
[0005] The difficulties therein result from the complexity of the
cooling process and the behavior of the continuous casting on the
one hand, and the tubular mold on the other.
[0006] The object of the present invention is to adapt such a
tubular mold made of copper with regard to all existing
technological requirements for the cooling processes at casting
rates of approximately 3-10 m/min.
[0007] The proposed object is met according to the present
invention in that the inner geometrical cross-section shape and the
corresponding measurements are carried out analogous to the locally
deducible quantity of solidification heat for a specified casting
rate and analogous to the expansion of the tubular mold. The
tubular mold is thereby adapted so as to optimize the process,
wherein the solidification heat is dissipated according to a (high)
casting rate based on the mold height (mold length) both by means
of the casting contraction behavior as well as the mold expansion
during casting operation.
[0008] The casting shell always advantageously abuts the inner
surface (hot side) of the mold without air gaps. This makes it
possible, for example, to take account of the magnified heat
quantity in the casting mirror area for casting contraction and
mold expansion. Based on these values the tubular mold is designed
with regard to its inner form and measurements. The values can be
used for example for mold heights of approximately 1000-1100
mm.
[0009] The tubular mold can be designed in the same way with regard
to its exterior form and measurements, wherein that the exterior
form is designed at least in separate height ranges analogous to
the mold expansion.
[0010] In addition to other criteria the casting material itself is
taken into account, in that the tubular mold is shaped with regard
to its geometrical cross-sectional forms based on the respective
steel grade.
[0011] A very pronounced contraction can be measured, for example,
in that the tubular mold in the area of the casting mirror exhibits
a section of greater conicity in accordance with the greater
contraction of the continuous casting.
[0012] A conicity is used on such a contraction section which
corresponds to the casting shell growth and the typical contraction
(on the basis of shell growth S=Key figure k*t; whereas t=casting
time), wherein the tubular mold exhibits under the section of
greater conicity a continuously varying conicity depending on the
casting shell growth and the contraction of the continuous
casting.
[0013] The conicity of the tubular mold and its wall thickness
result among others from the fact that under the tubular mold
section of greater conicity the wall volume is variably designed
corresponding to the dissipated heat quantity per unit of time.
[0014] The thermal expansion of the tubular mold can also be
controlled on its exterior surface by enlarging the exterior
surface of the tubular mold in the areas of reduced wall volume by
means of notches, ribs or the like.
[0015] The behavior of the continuous casting during contraction is
among others further advantageously influenced in that, starting at
the entry cross-section, a centric, approximately parabola-shaped
recess is provided per cross-section side.
[0016] Taking into account the decreasing contraction according to
the respective casting shell thickness, it is further provided that
the approximately parabola-shaped recess declines in the direction
toward the casting exit side. This is makes it possible to carry
out an individualized adjustment to the respective broadside and/or
edge of the entry cross-section.
[0017] Based on exemplified calculations it is further advantageous
that the length of the approximately parabola-shaped recess roughly
extends into half the mold height.
[0018] The contraction behavior of the continuous casting can be
further taken into consideration by adapting the length of the
approximately parabola-shaped recess to the contraction measure at
the height of the respective broadside and/or edge of the mold
cross-section.
[0019] A further development is achieved in that a plane-parallel
surface each is designed in the area of a corner radius which
opposes analogous counter surfaces in the inner cross-section
form.
[0020] The embodiments of the invention are illustrated in the
drawings which are described in detail as follows:
[0021] FIG. 1 is a cross-sectional view of a tubular mold with a
diagram of the solidification heat added across the mold
height;
[0022] FIG. 2 shows the same cross-sectional view as FIG. 1,
wherein FIG. 2A corresponds to "section A-A" and FIG. 2B
corresponds to "section B-B";
[0023] FIG. 3 shows the same cross-sectional view as FIG. 1,
wherein FIG. 3A corresponds to "section A-A" and FIG. 3B
corresponds to "section B-B";
[0024] FIG. 4 is a cross-sectional view with an approximately
parabola-shaped recess, FIG. 4A a "section A-A" and FIG. 4B a
"section B-B".
[0025] According to FIG. 1 the continuous casting mold is shown in
cross-section and serves the casting of molten metals, particularly
molten steel materials to form polygonal billet, bloom, preliminary
section castings 1 and the like. The continuous casting mold
comprises a tubular mold 2 made of copper or of copper alloys.
[0026] The entry cross-section 3 on the pouring-in side 4
represents a cross-section enlargement 5 compared to the exit
cross-section 6 on the casting exit side 7. The pouring-in side 4
and the casting exit side are continuously provided with a radius 8
(FIGS. 4A and 4B) in the transition.
[0027] On the right side across the mold height 11 there is a
diagram "D" showing the process during the dissipation of
solidification heat from the continuous casting 1. The dramatically
increasing temperature distribution in the area of the casting
mirror results therefrom.
[0028] The tubular mold 2 is henceforth built such that the inner
geometrical cross-section form 9 and the associated measurements 10
are set analogous to the locally deducible quantity of
solidification heat (see FIG. 1, right diagram "D") for a specified
(high) casting rate and analogous to the expansion of the tubular
mold 2, i.e., designed based on calculations and/or experience.
[0029] The exterior form 12 is thereby reduced at least in separate
height ranges 12 of the tubular mold 2 analogous to the thermal
expansion of the mold.
[0030] The values for the expansion or the contraction of casting
metals may also be taken into account in the geometrical
cross-section form 9 depending on the specific steel grade on
hand.
[0031] According to FIG. 1 to 4 the tubular mold 2 exhibits in the
area of the casting mirror 13 (FIG. 2) a section 14 of great
conicity and immediately adjacent a section 15 of even greater
conicity corresponding to the greatest contraction of the
continuous casting 1.
[0032] A continuously varying conicity 16 extends under the section
15 of greater conicity corresponding to the casting shell growth
and the contraction of the continuous casting 1. The wall volume 17
is thereby variable or reduced depending on the dissipated heat
quantity per time unit. In the areas of reduced wall volume 17 the
exterior surface 18 of the tubular mold 2 is enlarged by means of
notches, ribs 19 or the like (FIGS. 4A and 4B). These notches 19
are surrounded on the outside by a cooling medium (water) and are
located in a common water case (not shown) which surrounds the
continuous casting mold. The notches, ribs 19 or the like can also
be seen in FIGS. 3 and 3B.
[0033] In FIGS. 4 and 4A a centric, approximately parabola-shaped
recess 20 is arranged on each cross-section side 3a starting on the
entry cross-section 3. The parabola-shaped recess 20 diminishes in
depth and thus in width downwards in the direction toward the
casting exit side 7.
[0034] The length 20a of the parabola-shaped recess 20 thereby
extends approximately into half the height of the mold 11. The
length 20a of the parabola-shaped recess 20 is also adapted to
contraction measure for the height of the respective broadside
and/edge 21 of the mold cross-section 22 (FIG. 4A).
[0035] In the area of the corner radius 8 there is each one
plane-parallel surface 23 extending downwards, each opposing
respective analogous counter surfaces 24 in the inner cross-section
form 9.
LIST OF REFERENCE NUMBERS
[0036] TABLE-US-00001 1 Billet, bloom, preliminary section casting
2 Tubular mold (made of copper) 3 Entry cross-section 3a
Cross-section side 4 Pouring-in side 5 Cross-section enlargement 6
Exit cross-section 7 Casting exit side 8 Corner radius 9
Geometrical cross-section form 10 Measurement 11 Mold height 12
Exterior form 13 Casting mirror 14 Section of great conicity 15
Section of greater conicity 16 Varied conicity 17 Wall volume of
the tubular mold 18 Exterior surface of the tubular mold 19
Notches, ribs 20 Parabola-shaped recess 20a Length of the recess 21
Broadside and/or edge 22 Mold cross-section 23 Plane-parallel
surface 24 Identical counter surface
* * * * *