U.S. patent application number 11/386924 was filed with the patent office on 2006-08-17 for continuous casting mold and a continuous casting method of copper alloy.
This patent application is currently assigned to SUMITOMO METAL INDUSTRIES, LTD.. Invention is credited to Masahiro Aoki, Yasuhiro Maehara, Keiji Nakajima, Mitsuharu Yonemura, Naotsugu Yoshida.
Application Number | 20060180293 11/386924 |
Document ID | / |
Family ID | 34381782 |
Filed Date | 2006-08-17 |
United States Patent
Application |
20060180293 |
Kind Code |
A1 |
Maehara; Yasuhiro ; et
al. |
August 17, 2006 |
Continuous casting mold and a continuous casting method of copper
alloy
Abstract
A continuous casting mold for a Cu alloy, using any one member
selected from a glassy carbon, a metal-based self-lubricating
composite or a graphite with a bulk density exceeding 1.92, at
least for the mold member including the solidification starting
position of the Cu alloy melt. A continuous casting mold for a Cu
alloy, composed of any one member selected from a graphite, a
ceramic and a metal member or of a combination of two or more parts
of members thereof, in which at least the inner wall in the
solidification starting position of the Cu alloy melt is coated
with a self-lubricant or a metal-based self-lubricating composite
material. A continuous casting method of a Cu alloy, comprised of
giving, at the time of continuously casting the Cu alloy by an
intermittent pulling out method, a vibration that has a frequency
larger than the slab intermittent pulling out frequency by two
orders or more and that has a component vertical to the pulling out
direction of the slab, or continuously supplying a lubricant or an
anti-sticking material between the inner wall of the mold and the
slab.
Inventors: |
Maehara; Yasuhiro;
(Kobe-shi, JP) ; Yonemura; Mitsuharu;
(Takarazuka-shi, JP) ; Nakajima; Keiji; (Kobe,
JP) ; Yoshida; Naotsugu; (Kashima-shi, JP) ;
Aoki; Masahiro; (Joetsu-shi, JP) |
Correspondence
Address: |
BUCHANAN INGERSOLL PC;(INCLUDING BURNS, DOANE, SWECKER & MATHIS)
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
SUMITOMO METAL INDUSTRIES,
LTD.
Osaka-shi
JP
|
Family ID: |
34381782 |
Appl. No.: |
11/386924 |
Filed: |
March 23, 2006 |
Current U.S.
Class: |
164/459 ;
164/418 |
Current CPC
Class: |
C22C 9/10 20130101; C22C
9/00 20130101; C22C 9/04 20130101; C22C 9/02 20130101; B22D 11/143
20130101; B22D 11/004 20130101; B22D 11/12 20130101; B22D 11/059
20130101 |
Class at
Publication: |
164/459 ;
164/418 |
International
Class: |
B22D 11/00 20060101
B22D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 24, 2003 |
JP |
2003-331909 |
Mar 29, 2004 |
JP |
2004-097223 |
Aug 11, 2004 |
JP |
2004-234641 |
Claims
1-14. (canceled)
15. A continuous casting mold for a Cu alloy, using a glassy carbon
or a metal-based self-lubricating composite member, at least for
the mold member including the solidification starting position of
the Cu alloy melt.
16. A continuous casting mold for a Cu alloy, composed of any one
member selected from a graphite, a ceramic and a metal member or of
a combination of two or more parts of members thereof, in which at
least the inner wall in the solidification starting position of the
Cu alloy melt is coated with a self-lubricant or a metal-based
self-lubricating composite material.
17. A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which the self-lubricant
or the metal-based self-lubricating composite member is used at
least for the inner wall in the solidification starting position of
the Cu alloy melt.
18. A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which at least the inner
wall in the solidification starting position of the Cu alloy melt
is coated with a self-lubricant or a metal-based self-lubricating
composite material.
19. The continuous casting mold for a Cu alloy according to claim
15, wherein the inner wall in the position that contacts with the
Cu alloy melt is coated with a ceramic material.
20. A continuous casting method of a Cu alloy, comprised of
performing continuous casting by a slab intermittent pulling out
method by use of the mold according to claim 15.
21. The continuous casting method of a Cu alloy according to claim
20, comprised of giving, at the time of continuously casting the Cu
alloy by an intermittent pulling out method, a vibration that has a
frequency larger than the intermittent pulling out frequency by two
orders or more and that has a component vertical to the pulling out
direction of the slab.
22. The continuous casting method of a Cu alloy according to claim
20, comprised of continuously supplying, at the time of
continuously casting the Cu alloy by an intermittent pulling out
method, a lubricant or an anti-sticking material between the inner
wall of the mold and the slab.
23. A continuous casting method of a Cu alloy according to claim
20, the cooling rate from the temperature of the start of
solidification to 600.degree. C. is 0.5.degree. C./s or more, at
the time of continuously casting the Cu alloy.
24. The continuous casting method of a Cu alloy according to claim
20, wherein the Cu alloy contains, by mass %, one or more
components selected from Cr: 0.01 to 5%, Ti: 0.01 to 5%, Zr: 0.01
to 5%, Nb: 0.01 to 5%, Ta: 0.01 to 5%, Al: 0.01 to 5%, Mo: 0.01 to
5%, V: 0.01 to 5%, Co: 0.01 to 5%, Mn: 0.01 to 5%, Si: 0.01 to 5%,
Be: 0.01 to 5%, and Hf: 0.01 to 5%.
25. The continuous casting method of a Cu alloy according to claim
24, wherein the Cu alloy further contains, by mass %, 0.001 to 5%
in total of one or more of the alloy components selected from at
least one group of the following three groups: First group: 0.001
to 1 mass % in total of one or more selected from P, B, Sb, Bi, Pb,
Cd, S and As; Second group: 0.01 to 5 mass % in total of one or
more selected from Sn, Ag, Zn, Ni, Au, Pd, Fe, W, In and Ge; and
Third group: 0.01 to 3 mass % in total of one or more selected from
Te, Se, Sr, TI, Rb, Cs, Ba, Re, Os, Rh, Po, Ga, Tc, Ru, Pd, Ir, Pt
and Ta.
26. The continuous casting method of a Cu alloy according to claim
24, wherein the Cu alloy further contains, by mass %, 0.001 to 2%
in total of one or more of alloy components selected from Li, Ca,
Mg and rare earth elements.
Description
TECHNICAL FIELD
[0001] The present invention relates to a continuous casting mold
and a continuous casting method of a Cu alloy, particularly, a
casting mold used for a direct-connection type of continuous
casting machine, in which a mold is directly connected to a holding
furnace, and a continuous casting method of a Cu alloy using this
mold.
BACKGROUND ART
[0002] Along with the recent development of Information Technology,
particularly, in the technology of the cellular phone, portable
computer or the automobile electronic equipment, it has become more
important to enhance the performance of a Cu alloy used for
electric and electronic parts such as a lead frame, a terminal, a
connector, a spring or a contact element. The typical first
necessary characteristic is higher strength for a reduction in
weight, and the second is higher electric conductivity for
suppressing a rise of electric resistance caused by reduction in
the sectional area due to the reduction in weight. On the other
hand, the improvement in workability such as bending workability
due to the downsizing of parts, the improvement in heat resistance
in order to ensure usability even in relatively severe
environments, and the improvement in fatigue strength are also
important problems.
[0003] Such a highly strong and highly electric-conductive material
can also be applied to safety tool materials used in an environment
such as an ammunition chamber or a coal mine which needs excellent
spark generation resistance, in addition to the wear resistance
needed for conventional tools. Such a material is exemplified the
Cu alloy disclosed in the Patent Document 1 below.
[0004] Continuous casting of a Cu alloy executed mainly in two
methods is described below.
[0005] The first method is a direct-connection type of continuous
casting including horizontal type and vertical type casting, using
a graphite-made mold directly connected to a holding furnace. Since
a supply of a lubricant is extremely difficult in the
direct-connection type of continuous casting, graphite with a bulk
density of 1.7 to 1.9, which has a self-lubricating property and
high heat conductivity, has widely been used for the mold material.
This method is suitable for obtaining a slab or a bloom with
relatively small sectional area. In such type of continuous casting
process, the cooling rate after solidification is relatively high,
leading to a high performance of a final product even without a
subsequent hot process such as a solution treatment or a hot
working.
[0006] The second method is a non-direct-connection type of
continuous casting including vertical type, curved type and
vertical-curved type casting, described in the Patent Document 1,
in which melt is poured into a mold made of a metal such as Cu or
an alloy such as a Cu alloy through a nozzle immersed into a melt
pool. In the non-direct-connection type of continuous casting, the
slabs to be cast are limited to a relatively large size with a
thickness of about 100 mm or more, since the nozzle can be immersed
into the melt pool within the mold. This method essentially
requires a hot process such as a solution treatment or a hot
working in the later production process because of a low cooling
rate in the cooling process after solidification.
[0007] A proper method is selected from these two kinds of
continuous casting methods according to the required alloy
composition, slab sectional shape, cooling rate, or the like. In
general, the former direct connection type is adapted when a high
cooling rate is needed or when the Cu alloy is free from highly
reactive elements with C in the graphite. The latter non-direct
connection type is adapted when a slab of a large sectional size is
needed or when the Cu alloy contains highly reactive elements with
C in the graphite.
[0008] [Patent Document] Japanese Patent Unexamined Publication No.
S61-250134.
DISCLOSURE OF THE INVENTION
Problem to be Solved by the Invention
[0009] The primary objective of the present invention is to provide
a continuous casting mold suitable for a direct-connection type of
continuous casting of the Cu alloy containing elements such as Zr,
Ti, and Cr that are reactive with C. The second objective of the
present invention is to provide a continuous casting method of the
Cu alloy using the above-described mold. The continuous casting
mold of the present invention is highly effective for continuous
casting not only of Cu alloys but also of such materials as
non-ferrous metals other than Cu alloys.
MEANS FOR SOLVING THE PROBLEMS
[0010] In many cases, new Cu alloys intended for higher strength
and higher electric conductivity contain elements such as Zr, Ti
and Cr, which easily react with C. They also need a high cooling
rate in the cooling process after solidification in order to attain
satisfactory characteristics of the final products. However, these
alloys are found to have the following problems, which results from
the reaction of above-mentioned elements with C in the graphite
mold.
[0011] In the application of the above-mentioned Cu alloys to the
direct-connection type of continuous casting, the elements such as
Zr, Ti and/or Cr in the melt, which are reactive with C in the
graphite, results in a sticking of the initially formed
solidification shell to the mold, with remarkable increase of the
pulling out resistance. As a result, problems such as a mold damage
due to the sticking and a surface cracking of the slab are often
caused. The application of these kinds of alloys to the
direct-connection type of continuous casting is thus quite
difficult. This is also the reason why the development of the high
performance alloy using the conventional process has been
restricted.
[0012] To solve these problems, the present invention relates to a
continuous casting mold, capable of providing a sufficiently high
cooling rate in the cooling process after solidification, while
suppressing the sticking of the initially formed solidification
shell to the mold, and a continuous casting method using the mold,
and involves the following inventions of continuous casting molds
(1) to (5) and inventions of continuous casting methods (6) to
(12). These inventions are hereinafter referred to as the present
inventions (1) to (12), respectively, or often are referred to
collectively as the present invention.
[0013] (1) A continuous casting mold for a Cu alloy, using any one
member selected from a glassy carbon or a metal-based
self-lubricating composite, at least for the mold member including
the solidification starting position of the Cu alloy melt.
[0014] (2) A continuous casting mold for a Cu alloy, composed of
any one member selected from a graphite, a ceramic and a metal
member or of a combination of two or more parts of members thereof,
in which at least the inner wall in the solidification starting
position of the Cu alloy melt is coated with a self-lubricant or a
metal-based self-lubricating composite material.
[0015] (3) A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which the self-lubricant
or the metal-based self-lubricating composite member is used at
least for the inner wall in the solidification starting position of
the Cu alloy melt.
[0016] (4) A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which at least the inner
wall in the solidification starting position of the Cu alloy melt
is coated with a self-lubricant or a metal-based self-lubricating
composite material.
[0017] (5) The continuous casting mold for a Cu alloy according to
any one of (1) to (4) above, wherein the inner wall in the position
that contacts with the Cu alloy melt is coated with a ceramic
material.
[0018] (6) A continuous casting method of a Cu alloy, comprised of
performing continuous casting by an intermittent pulling out
method, by use of any one of the molds described in (1) to (5)
above.
[0019] (7) A continuous casting method of a Cu alloy according to
(6) above, comprised of giving, at the time of continuously casting
the Cu alloy by an intermittent pulling out method, a vibration
that has a frequency larger than the intermittent pulling out
frequency by two orders or more and that has a component vertical
to the pulling out direction of the slab.
[0020] (8) A continuous casting method of a. Cu alloy according to
(6) or (7) above, comprised of continuously supplying, at the time
of continuously casting the Cu alloy by an intermittent pulling out
method, a lubricant or an anti-sticking material between the inner
wall of the mold and the slab.
[0021] (9) A continuous casting method of a Cu alloy according to
any one of (6) to (8) above, the cooling rate from the temperature
of the start of solidification to 600.degree. C. is 0.5.degree.
C./s or more, at the time of continuously casting the Cu alloy.
[0022] (10) A continuous casting method of a Cu alloy according to
any one of (6) to (9) above, wherein the Cu alloy contains, by mass
%, one or more components selected from Cr: 0.01 to 5%, Ti: 0.01 to
5%, Zr: 0.01 to 5%, Nb: 0.01 to 5%, Ta: 0.01 to 5%, Al: 0.01 to 5%,
Mo: 0.01 to 5%, V: 0.01 to 5%, Co: 0.01 to 5%, Mn: 0.01 to 5%, Si:
0.01 to 5%, Be: 0.01 to 5%, and Hf: 0.01 to 5%.
[0023] (11) A continuous casting method of a Cu alloy according to
(10) above, wherein the Cu alloy further contains, by mass %, 0.001
to 5% in total of one or more of alloy components selected from at
least one group of the following three groups:
[0024] First group: 0.001 to 1 mass % in total of one or more
selected from P, B, Sb, Bi, Pb, Cd, S and As;
[0025] Second group: 0.01 to 5 mass % in total of one or more
selected from Sn, Ag, Zn, Ni, Au, Pd, Fe, W, In and Ge; and
[0026] Third group: 0.01 to 3 mass % in total of one or more
selected from Te, Se, Sr, Tl, Rb, Cs, Ba, Re, Os, Rh, Po, Ga, Tc,
Ru, Pd, Ir, Pt and Ta.
[0027] (12) A continuous casting method of a Cu alloy according to
(10) or (11) above, wherein the Cu alloy further contains, by mass
%, 0.001 to 2% in total of one or more of alloy components selected
from Li, Ca, Mg and rare earth elements.
EFFECT OF THE INVENTION
[0028] According to the present invention, a continuous casting
mold capable of continuously and stably producing a sound slab can
be provided. A continuous casting method of a Cu alloy capable of
ensuring excellent characteristics such as strength, electric
conductivity, bending workability and fatigue strength of the final
product after working and heat treatment, can be provided.
Particularly, in application to casting of a Cu alloy containing
Zr, Ti, Cr, Ta, V and so on, which are elements that easily form
into carbides, a profound effect can be obtained. The present
invention is highly effective not only for Cu alloys but also for
such materials as non-ferrous metals other than Cu alloys.
BEST MODE FOR CARRYING OUT THE INVENTION
[0029] Preferred embodiments of the present invention will be
described.
<Mold of the Present Invention>
[0030] Examples of a mold for a direct-connection type of
horizontal continuous casting according to the present invention,
are shown in FIGS. 1 to 7. In each figure, the mold is directly
connected to a refractory constructing the holding furnace wall 2
that stores a Cu alloy melt 1. In order to protect the connection
part of the holding furnace wall, a connecting refractory, such as
a feeding nozzle, may be provided between the holding furnace wall
and the mold. A cooling jacket 5, adapted to carry cooling water or
the like into the mold, is arranged closely to the outside of a
mold member 3 and/or another part of mold member 3', in which heat
extraction is performed by primarily cooling the Cu alloy melt, and
the solidification proceeds to form into a slab 4. The slab 4
leaving the mold is subjected to secondary cooling 6 by water
spray, air spray, air-water mixed spray or the like. The slab 4 is
pulled out in an arrowed direction 7.
[0031] The mold according to the present invention may include a
coating 8 applied to the inner wall of the mold in the
solidification starting position 10 of the Cu alloy melt. It may
include a coating 9 applied to the inner wall in the position of
the mold, which is located at an upper stream part than the
solidification starting position. The mold may be composed of a
plurality of parts of mold members, for example, a part of mold
member 3 and another part of mold member 3'.
[0032] The mold inner wall might be deteriorated by oxidation at
the time of preheating before casting. In order to prevent this
deterioration, an oxidation resisting coating such as metal
plating, is preferably applied at least to the inner wall of the
mold in the solidification starting position of the inner wall
surface of the mold. The oxidation resisting coating material is
not particularly limited, but one easily soluble to the melt at the
time of casting without deteriorating the characteristics or the
like of the final product, is preferably used. In casting of the Cu
alloy, for example, Cu is preferably used as the coating material,
with a thickness of about several micrometers.
[0033] The solidification starting position in the present
invention is defined as follows. In the mold, molten Cu alloy is
fed from the holding furnace, and forms into a solidification shell
in a certain position in the mold. This solidification shell
forming position is called the solidification starting position.
The solidification starting position is slightly varied depending
on the casting conditions such as the temperature of the melt in
the holding furnace, the cooling condition in both primary and
secondary stages, and the pulling out velocity and so on. Thus, the
solidification starting position has a certain fluctuation in the
pulling out direction.
[0034] FIGS. 1 to 7 show examples of the mold for a
direct-connection type of horizontal continuous casting according
to the present invention, while the mold for a direct connection
type of vertical continuous casting can be shown by rotating these
figures clockwise by 90.degree..
[0035] A continuous casting mold for a Cu alloy according to the
present invention will be further described in detail in terms of
types (A) to (E). Further, a method for continuously casting a Cu
alloy by use of these molds will also be described.
[0036] (A) A continuous casting mold for a Cu alloy, using a glassy
carbon or a metal-based self-lubricating composite member, at least
for the mold member including the solidification starting position
of the Cu alloy melt:
[0037] FIG. 1 is a schematic view of a continuous casting mold for
a Cu alloy as one example of the continuous casting mold, according
to the present invention, using a glassy carbon or a metal-based
self-lubricating composite material for the mold member 3 including
the solidification starting position 10 of the Cu alloy melt.
[0038] By using the glassy carbon or the metal-based
self-lubricating composite material, at least for the mold member
including the solidification starting position of the Cu alloy
melt, a sound slab can be produced continuously, efficiently, and
stably.
[0039] A continuous casting method of a Cu alloy capable of
ensuring excellent characteristics such as strength, electric
conductivity and fatigue strength of a final product after working
and heat treatment, can be provided. Particularly, in application
to casting of the Cu alloy containing elements such as Zr, Ti, Cr,
Ta and V, which easily form into carbides, a profound effect can be
obtained.
[0040] The present inventors found that, when the direct-connection
type of continuous casting is executed using a mold member which is
made of a conventional graphite material with a bulk density of 1.7
to 1.9, the Cu alloy melt penetrates into a number of open pores
which are on the graphite surface, whereby the initially formed
solidification shell is stuck to the mold, resulting in mold damage
with increase of the pulling out resistance or sometimes into an
interruption of process. It was also found that, when the melt
contains elements such as Zr, Ti and Cr which are reactive with C,
the formation of the carbides in the boundary between the melt and
the mold further causes sticking of the initially formed
solidification shell to the mold, resulting in mold damage due to
mold biting or into an interruption of the slab pulling out
process.
[0041] It is found effective for solving these problems to use the
mold material that rarely reacts with the elements in the melt.
[0042] Namely, use of a glassy carbon or a metal-based
self-lubricating composite material is effective from the viewpoint
of the reaction between the mold material and the melt.
[0043] The glassy carbon material has characteristics of being,
rarely oxidized, compared with the graphite, and also being rarely
reactive with Zr, Ti, and Cr, and therefore, it was found that the
purpose can be sufficiently attained.
[0044] The metal-based self-lubricating composite material means a
cermet obtained by dispersing and mixing a self-lubricant such as
MoS.sub.2, WS.sub.2, BN or mica that rarely reacts with Ti, Cr or
Zr into a metal matrix. This composite material can also
sufficiently attain the purpose.
[0045] The method for producing the composite material is not
particularly limited. For example, mixing a metal powder with a
self-lubricant particle, followed by pressing and sintering, can
produce the composite material.
[0046] The content of the self-lubricant in the composite material
is not particularly limited, but is, by volume %, preferably 10% or
more, more preferably 30% or more, and further preferably 80% or
more. Although an increased content of the self-lubricant leads to
an improvement in the reaction resistance and the lubricating
property, it causes the deterioration of the mechanical properties
such as strength and heat impact resistance, therefore the content
is, by volume %, preferably controlled to 85% or less.
[0047] The metal constituting the composite material with the
self-lubricant is not particularly limited, and any metal or alloy
can be used. Use of a metal and/or an alloy having a high melting
point and high thermal conductivity is preferred since the mold
material makes contact with a Cu alloy melt. The specific examples
of the metal of the alloy are a Cu alloy, a stainless steel, a Ni
alloy, a Co alloy, and a W alloy.
[0048] (Deleted)
[0049] In continuous casting of a Cu alloy by means of an
intermittent pulling out method by use of this mold, a further
profound effect can be obtained by adopting either or both of
measures of (1) giving a vibration that has a frequency larger than
the intermittent frequency by two orders or more and that has a
component vertical to the pulling out direction of the slab and (2)
continuously supplying a lubricant or an anti-sticking material
between the inner wall of the mold and the slab.
[0050] According to the intermittent pulling out method, since the
frictional resistance between the mold inner wall and the slab is
reduced in terms of the lubricating effect, a sufficiently sound
slab can be continuously, efficiently, and stably produced.
[0051] If a vibration that has a frequency larger than the
intermittent frequency by two orders or more and that has a
component vertical to the pulling out direction is given to the
mold, the similar effect can be obtained over a longer time. An
increased vibration frequency is more preferable, and it is
preferably set to 5000 cpm (83 Hz) or more, and more preferably to
60000 cpm (1 kHz) or more, which is close to the ultrasonic
area.
[0052] It is recommended to use a fine particle of MoS.sub.2,
WS.sub.2, BN, mica, or carbon as the lubricant to be supplied
between the mold inner wall and the slab. Among them, a superfine
particle of CaCO.sub.3, which is difficult to agglomerate, is
strongly recommended as the anti-sticking material. The continuous
supply thereof is performed, for example, by injecting a solution
of the fine particle of the lubricant or anti-sticking material
suspended in mineral oil, synthetic ester or a mixture thereof
through a number of through-holes of about 20 .mu.m provided in the
mold inner wall by the use of a pressure pump. A sufficient effect
can be obtained in an injection quantity of about 0.1
cc/cm.sup.2min, which is as little as sweat.
[0053] (B) A continuous casting mold for a Cu alloy, composed of
any one member selected from a graphite, a ceramic and a metal
member or of a combination of two or more parts of members thereof,
in which at least the inner wall in the solidification starting
position of the Cu alloy melt is coated with a self-lubricant or a
metal-based self-lubricating composite material:
[0054] FIG. 2 is a schematic view of a continuous casting mold for
a Cu alloy as an example of the continuous casting mold according
to the present invention, in which the mold member 3 is composed of
any one member selected from a graphite, a ceramic and a metal, and
in which a coating 8 of a self-lubricant or a metal-based
self-lubricating composite material is applied to the inner wall in
the solidification starting position 10 of the Cu alloy melt.
[0055] A mold which is composed of any one member selected from the
graphite, the ceramic and the metal member, with a coating of the
self-lubricant or the metal-based self-lubricating composite
material applied to the inner wall of the mold, is used, whereby a
sound slab can be continuously, efficiently and stably
produced.
[0056] A continuous casting method of a Cu alloy capable of
ensuring excellent characteristics such as strength, electric
conductivity and fatigue strength of the final product after
working and heat treatment, can be provided. Particularly, in
application to casting of a Cu alloy containing elements such as
Zr, Ti, Cr, Ta and V, which easily form into carbides, a profound
effect can be obtained.
[0057] When the graphite is selected as the mold material, a
compact coating material composed of C, for example, a glassy
carbon, a layered carbon and a diamond-like carbon, which are
self-lubricant materials, are preferably selected in order to
enhance the adhesion between the mold material and the coating
film. Since the surface unevenness of the coating film almost
reflects the surface unevenness of the graphite itself, it is
desirable to select a graphite with a bulk density as high as
possible. Although the bulk density is not particularly limited, it
is preferably 1.7 or more, more preferably 1.8 or more, or further
preferably more than 1.92.
[0058] As the ceramic, an inorganic material composed of one or
more selected from oxides, nitrides, carbides and borides is used.
Although it is not particularly limited, a BN material and a sialon
material (a compound consisting of Si, Al, O, and N, shown by a
phase diagram of Si.sub.3N.sub.4--AlN--Al.sub.2O.sub.3--SiO.sub.2)
are preferable because of the mechanical strength and thermal
conductivity to be provided as the mold material.
[0059] When a material with low thermal conductivity is used, the
thinner mold thickness, that is, the narrower distance between the
slab and a cooling jacket is preferably adapted. When a ceramic
composed of sintering BN and sialon is selected, a compact coating
material composed of a nitride compound, for example, a BN material
that is a self-lubricant is preferably selected in order to enhance
the adhesion between the mold material and the coating film.
[0060] The metal is not particularly limited, and any metal or
alloy can be used. Use of a metal or an alloy having a high melting
point and high thermal conductivity is preferred, for example, a Cu
alloy, a stainless steel, a Ni alloy, a Co alloy, a W alloy, since
the mold material will make contact with the Cu alloy melt. When
the metal is selected, a metal-based compact coating material such
as a metal-based self-lubricant material is preferably selected in
order to enhance the adhesion between the mold material and the
coating film.
[0061] The metal-based self-lubricating composite material means a
cermet obtained by dispersing and mixing a self-lubricant such as
MoS.sub.2, WS.sub.2, BN and mica that rarely reacts with Zr, Ti or
Cr in a metal matrix. It was found that the purpose can be
sufficiently attained by applying this to the metal or alloy used
for the mold material by electroless plating, electrolytic plating
or spray coating. After the coating, the surface is polished
preferably with an emery paper of about No. 1000.
[0062] The content of the self-lubricant in the composite material
(cermet) to be plated or sprayed is not particularly limited.
However, although the reaction resistance and the lubricating
property are improved, an increased content of the self-lubricant
causes deterioration of the peeling resistance of the film, then
the content is preferably set to about 10 to 30 vol. %.
[0063] The metal in the composite material to be coated by plating
is not particularly limited, and any metal or alloy can be used.
Particularly, use of a metal or an alloy having a high melting
point and high thermal conductivity is preferred, for example, a Cu
alloy, stainless steel, a Ni alloy, a Co alloy and a W alloy.
[0064] In the continuous casting of a Cu alloy by the intermittent
pulling out method by the use of this mold, a further profound
effect can be obtained by adapting either or both of measures of
(1) giving a vibration that has a frequency larger than the
intermittent cycle by two orders or more and that has a component
vertical to the pulling out direction to the mold and (2)
continuously supplying a lubricant or an anti-sticking material
between an inner wall of the mold and the slab.
[0065] According to the intermittent pulling out method, since the
frictional resistance between the inner wall of the mold and the
slab is reduced in terms of lubricating effect, a sufficiently
sound slab can be continuously, efficiently and safely
produced.
[0066] If a vibration that has a frequency larger than the
intermittent pulling out frequency by two orders or more and that
has a component vertical to the pulling out direction is given to
the mold, the similar effect can be obtained over a longer time. An
increased vibration frequency is more preferable, and the frequency
is preferably set to 5000 cpm (83 Hz) or more, and more preferably
to 60000 cpm (1 kHz) or more, which is close to the ultrasonic
area.
[0067] The lubricant to be supplied between the inner wall of the
mold and the slab is the same as described above.
[0068] (C) A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which the self-lubricant
or the metal-based self-lubricating composite member is used at
least for the inner wall in the solidification starting position of
the Cu alloy melt:
[0069] FIG. 3 is a schematic view of a continuous casting mold for
a Cu alloy as an example of the continuous casting mold according
to the present invention. This is an example of the mold that is
composed of a combination of plurality of parts, that is, the mold
composed of a part of mold member 3 including an inner wall in the
solidification starting position 10 of the Cu alloy melt, and
another part of mold member 3'. The self-lubricant or the
metal-based self-lubricating composite member is used for the part
of mold member 3 including the inner wall in the solidification
starting position 10 of the Cu alloy melt, and any one member
selected from the graphite, the ceramic and the metal member is
used for the other part of mold member 3'.
[0070] The mold composed of a plurality of parts, that is, the mold
composed of a combination of a part of mold member including an
inner wall in the solidification starting position, using a
self-lubricant or a metal-based self-lubricating composite
material, and another part of mold member using any one of the
selected from a self-lubricant, a metal-based self-lubricating
composite, a graphite, a ceramic and a metal material, leads to a
sound slab which can be continuously, efficiently and stably
produced.
[0071] And a continuous casting method of a Cu alloy ensuring
excellent characteristics such as strength, electric conductivity,
bending workability and fatigue strength of a final product after
working and heat treatment can be provided. Particularly, in
application to casting of a Cu alloy containing elements such as
Zr, Ti, Cr, Ta and V that easily form into carbides, a profound
effect can be obtained.
[0072] As the part of mold member including the inner wall, any of
a glassy carbon, a layered carbon, a BN (example 22), and a
metal-based self-lubricating composite member obtained by
dispersing and mixing a self-lubricant such as MoS.sub.2, WS.sub.2,
BN, or mica that rarely reacts with Zr, Ti or Cr in a metal matrix
can be selected. The graphite, the ceramic and the metal members to
be used for the other part of mold member are the same as described
above.
[0073] (D) A continuous casting mold for a Cu alloy, composed of a
combination of two or more parts of members selected from a
self-lubricant, a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member, in which at least the inner
wall in the solidification starting position of the Cu alloy melt
is coated with a self-lubricant or a metal-based self-lubricating
composite material:
[0074] FIG. 4 is a schematic view of a continuous casting mold for
a Cu alloy as one example of the continuous casting mold according
to the present invention, which is composed of a plurality of parts
of members, and which has a coating 8 of a self-lubricant or a
metal-based self-lubricating composite material applied to the
inner wall of the mold in the solidification starting position 10
of the Cu alloy melt. The mold is composed of a part of mold member
3 and another part of mold member 3', using two kinds of parts of
members selected from a metal-based self-lubricating composite, a
graphite, a ceramic and a metal member.
[0075] The mold, which is composed of a part of any one member of
mold selected from a graphite, a ceramic and a metal member, and
another downstream part of a metal-based self-lubricating composite
or a graphite member, has a coating of the self-lubricant or the
metal-based self-lubricating composite material applied to the
inner wall in the solidification starting position of a Cu alloy
melt. The mold leads to a sound slab that can be continuously,
efficiently and stably produced. And a continuous casting method of
the Cu alloy ensuring excellent characteristics such as strength,
electric conductivity, bending workability and fatigue strength of
the final product after working and heat treatment, can be
provided. Particularly, in application to a Cu alloy containing
elements such as Zr, Ti, Cr, Ta and V that easily form into
carbides, a profound effect can be obtained.
[0076] The graphite member, the ceramic member, the metal member,
and the metal-based self-lubricating composite member to be used
for the mold member are the same as described above. As for the
coating to the inner wall of the mold, any of the glassy carbon,
the layered carbon, and the BN which are self-lubricants and the
metal-based self-lubricating composite member obtained by
dispersing and mixing self-lubricants such as MoS.sub.2, WS.sub.2,
BN and mica, that rarely react with Zr, Ti or Cr in a metal matrix,
can be selected.
[0077] (E) The continuous casting mold for a Cu alloy according to
any one of (A) to (D) above, wherein the inner wall in the position
that contacts with the Cu alloy melt is coated with a ceramic
material:
[0078] Another example of the continuous casting mold according to
the present invention, is shown in FIG. 5. In this continuous
casting mold for a Cu alloy, the mold member 3 including a mold
portion in the solidification starting position 10 of the Cu alloy
melt, is composed of a metal-based self-lubricating composite, and
a coating 9 of a ceramic material is applied to the inner wall in
the position that contacts with the Cu alloy melt in order to
suppress the reaction with the melt. The coating method of the
ceramic can be applied by spraying, CVD, etc.
[0079] The other example of the continuous casting mold according
to the present invention, is shown in FIG. 6. This continuous
casting mold for a Cu alloy is composed of a metal member for the
mold member 3. in which a coating 8 of the metal-based
self-lubricating composite material is applied to the inner wall in
the solidification starting position 10 of the Cu alloy melt, and a
coating 9 of the ceramic is applied to the inner wall in the
position of the mold that contacts with the Cu alloy melt in order
to suppress the reaction with the melt. The coating method of the
ceramic is the same as described above.
[0080] Another example of the continuous casting mold according to
the present invention is further, shown in FIG. 7. This continuous
casting mold for a Cu alloy is composed of an upstream part of mold
of a metal member and another downstream part of mold of a graphite
member. The part of mold of a metal member has a coating 8 of a
metal-based self-lubricating composite material applied to the
inner wall in the solidification starting position 10 of the Cu
alloy melt, and has a coating 9 of a ceramic material applied to
the inner wall in the position of the mold that contacts with the
Cu alloy melt in order to suppress the reaction with the melt. The
coating method of the ceramic is the same as described above.
[0081] As described in FIGS. 5 to 7, when the part of mold is
composed of the metal or metal-based self-lubricating composite
member, it is further effective to apply the coating of the ceramic
to the inner wall in the position of the mold that contacts with
the Cu alloy melt in order to avoid the reaction of the member with
Zr, Ti, Cr and so on in the melt. From the point of peeling
resistance, it is recommended as the coating method of ceramics to
apply a coating of a cushioning material about 50 .mu.m thick
(e.g., Ni plating, frame-coating of WC-27 wt % NiCr, and so on),
and then apply a ceramic coating about 200 .mu.m thick thereon by
frame coating. From the point of reaction resistance, a ceramic
composed of a further stable oxide, at a casting temperature of the
Cu alloy of 1250.degree. C., is preferred. For example, ZrO.sub.2-8
wt % Y.sub.2O.sub.3, ZrO.sub.2-25 wt % MgO, ZrO.sub.2-5 wt % CaO
and so on are recommended since no adhesion of the Cu alloy is
caused. More preferably, the inner wall in the position of the
upstream part of mold to be coated is preliminarily ground so as
not to form a difference in level after ceramic coating.
<Cu Alloys to Apply the Present Invention>
[0082] A profound effect can be obtained to any alloy when applying
the inventive method. It is the most effective to apply Cu alloys
including Cu--Ti--X alloys (X: Cr, Fe, Co, Ta, Nb, Mo, V, Mn, Be,
Si, Ni, Sn, Ag, etc.), Cu--Zr--X alloys (X: Cr, Fe, Co, Ta, Nb, Mo,
V, Mn, Be, Si, Ni, Sn, Ag, etc.), and Cu--Ti--Zr alloys. Some
compounds such as Ti--Cr and Zr--Cr and some metals such as Ti, Zr
and Cr precipitates in a certain high-temperature region in the
cooling process after solidification, which is apparent from the
phase diagrams of Ti--Cr, Zr--Cr and Ti--Zr binary alloy systems
shown in FIGS. 8, 9 and 10. These precipitates formed in a certain
high-temperature region in the cooling process after solidification
tend to be coarsened or aggregated, and it is quite difficult to
dissolve them by the subsequent solution treatment, which is
apparent from the phase diagrams.
[0083] A slab or bloom, according to the present invention, has a
profound effect through the process of working such as rolling at
600.degree. C. or lower and an aging treatment in the temperature
region of 150 to 750.degree. C., without a hot process such as hot
rolling and solution treatment described in the above-mentioned
Patent Document 1. The alloy is strengthened by a fine
precipitation of an intermetallic compound between Cu and an alloy
element such as Cu.sub.4Ti and Zr.sub.9Cu.sub.2 or between the
alloy elements, or a fine metal precipitate of Ti, Zr, Cr and so
on. Then, it is enhanced in electric conductivity by the resulting
reduction of the dissolved elements such as Ti, Zr, and Cr that are
harmful to electric conductivity. If a coarsened or agglomerate
precipitate is present before the aging treatment in the final
process, sufficient precipitation hardening cannot be attained. The
presence of such coarse particles deteriorates the bending
workability, fatigue characteristic and impact resistance of the
final product.
[0084] Since it is almost impossible to dissolve the coarsened or
agglomerate compounds formed in the cooling process after
solidification, increasing the cooling rate is necessary in order
to prevent the precipitation. The average cooling rate from the
temperature of the start of solidification to 600.degree. C. is
preferably 1.degree. C./s or more, and further preferably
10.degree. C./s or more.
[0085] A Cu alloys according to the present invention include the
Cu alloy containing, by mass %, one or more components selected
from Cr: 0.01 to 5%, Ti: 0.01 to 5%, Zr: 0.01 to 5%, Nb: 0.01 to
5%, Ta: 0.01 to 5%, Al: 0.01 to 5%, Mo: 0.01 to 5%, V: 0.01 to 5%,
Co: 0.01 to 5%, Mn: 0.01 to 5%, Si: 0.01 to 5%, Be: 0.01 to 5%, and
Hf: 0.01 to 5%.
[0086] Further, a Cu alloy containing, in addition to the above
components, by mass %, 0.001 to 5 mass % in total of one or more of
the alloy components selected from at least one group of the
following three groups is given:
[0087] First group: 0.001 to 1 mass % in total of one or more
selected from P, B, Sb, Bi, Pb, Cd, S and As;
[0088] Second group: 0.01 to 5 mass % in total of one or more
selected from Sn, Ag, Zn, Ni, Au, Pd, Fe, W, In and Ge; and
[0089] Third group: 0.01 to 3 mass % in total of one or more
selected from Te, Se, Sr, Ti, Rb, Cs, Ba, Re, Os, Rh, Po, Ga, Tc,
Ru, Pd, Ir, Pt and Ta.
[0090] A Cu alloy further containing 0.001 to 2 mass % in total of
one or more alloy components selected from Li, Ca, Mg and rare
earth elements is also given. The rare earth elements include Sc, Y
and lanthanoide, and each element may be added alone as raw
material or in a form of mish metal.
<Method for Producing Cu Alloy of the Present Invention>
[0091] Prior to continuous casting using the mold according to the
present invention, a Cu alloy with given chemical composition is
prepared by a melting furnace. The melting is desirably performed
under a non-oxidizing atmosphere. While the melting is inevitably
performed in the air, it is effective to suppress the oxidation by
shrouding the melt by a flux (e.g., cryolite, fluorite, etc.) or
charcoal particles. The melt is poured into a holding furnace. The
melting is desirably conducted using the holding furnace in order
to suppress the oxidation during the pouring.
[0092] Any of horizontal type, vertical type and so on can be
adapted to this continuous casting if it is the direct-connection
type of continuous casting using the mold directly connected to a
holding furnace.
[0093] The mold according to the present invention has minimized
operational problems in the production of the Cu alloy according to
the present invention because of the low reactivity with the melt
and a satisfactory lubricating property. However, since the inner
wall in the vicinity of the solidification starting position in the
mold is gradually thinned by the reaction with the melt or
abrasion, the slab might be caught thereby and not easily pulled
out. In such a case, it is effective to uniformly thin the inner
wall by adjusting the cooling condition of the mold, the pulling
out rate, or the like and moving the solidification position.
[0094] In general, the slab is intermittently pulled out. There are
various patterns: (A) pull-stop pattern, (B) pull-pushback pattern,
(C) pull-stop-pushback pattern and (D) pull-stop-pushback-stop
pattern, any of which can be adapted. The higher cooling rate in
the cooling process after solidification is desirable based on the
above-mentioned reason. Particularly, it is desirable to take
measure to raise the cooling rate in the secondary cooling zone
corresponding to the temperature range of coarsened or agglomerated
precipitation. Specifically, it is effective to employ water spray,
air spray, or air-water mixed spray just after leaving the mold
[0095] Thereafter, the final product is obtained by a combination
of working such as rolling at 600.degree. C. or lower and the aging
treatment at 150 to 750.degree. C. This working may be performed,
of course, in the cooling process after continuous casting.
EXAMPLE A
[0096] Cu alloys containing 2.0.+-.0.1 wt % of Ti, 1.0.+-.0.1 wt %
of Cr, 0.4.+-.0.02 wt % of Sn, and 0.1.+-.0.01 wt % of Zn were
melted in a high frequency vacuum melting furnace, and a continuous
casting test was carried out in 30 kinds of various production
methods shown in Tables 1 and 2. Each Cu alloy melt was transferred
to a holding furnace, and a slab of 20 mm.times.200 mm section was
intermittently pulled out in a predetermined condition while
holding the temperature of the furnace at 1250.degree. C. As a
refractory of the melting furnace and the holding furnace, graphite
was used. The oxidation of the melt was suppressed by an Ar gas
flow during pouring in addition to charcoal covering. In each test,
a water-cooled jacket composed of the Cu alloy was located adjacent
to the mold in order to perform primary cooling, and the slab
leaving the mold was cooled again by an air-water mixed spray. The
temperature measurement was performed basically after leaving the
mold by use of a thermocouple or radiation thermometer. In some
cases, the mold temperature was measured by boring a through-hole
from the mold outer wall to a position 5 mm inside and inserting
the thermocouple. Using both the measured data and the physical
properties of each mold material, whereby the solidification
starting position was estimated, performed a heat transfer
analysis. The average cooling rate from the solidification start
point to 600.degree. C. was calculated based on the above data. In
the tests shown in Tables 1 and 2, the cooling rate was controlled
to the range of 5.+-.2.degree. C.
[0097] [Table 1] TABLE-US-00001 TABLE 1 Average Vertical Forced
casting Test vibration of lubrication speed Casting Quality of slab
No. Mold mold of mold (mm/min) length (m) surface 2 The Present
Mold composed of a glassy carbon member. Non Non 258 60 m Excellent
Invention, Complete casting 3 The Present Mold composed of a
metal-based self-lubricating Non Non 258 60 m Satisfactory
Invention, composite member obtained by dispersing WS.sub.2 + BN
Complete (85 vol %) to W alloy followed by sintering. casting 7 The
Present Mold composed of a metal-based self-lubricating Frequency
Non 258 60 m Satisfactory Invention, composite member obtained by
dispersing WS.sub.2 + BN 5 kHz Complete (85 vol %) to W alloy
followed by sintering. Amplitude casting 5 .mu.m 8 The Present Mold
composed of a metal-based self-lubricating Non MoS.sub.2 fine 258
60 m Satisfactory Invention, composite member obtained by
dispersing WS.sub.2 + BN particle + Mineral Complete (85 vol %) to
W alloy followed by sintering. oil casting 9 The Present Mold
composed of a metal-based self-lubricating Frequency MoS.sub.2 fine
258 60 m Satisfactory Invention, composite member obtained by
dispersing WS.sub.2 + BN 5 kHz particle + Mineral Complete (85 vol
%) to W alloy followed by sintering. Amplitude oil casting 5 .mu.m
10 The Present Mold composed of a graphite member with bulk Non Non
258 60 m Excellent Invention, density of 1.82 with coating of a
glassy carbon Complete material applied to the inner wall. casting
11 The Present Mold composed of a graphite member with bulk Non Non
258 60 m Satisfactory Invention, density of 1.82 with coating of a
layered carbon Complete applied to the inner wall. casting 12 The
Present Mold composed of a ceramic member obtained by Non Non 258
60 m Satisfactory Invention, sintering sialone (30 vol %) and BN
(70 vol %) with Complete coating of BN applied to the inner wall by
CVD. casting 13 The Present Mold composed of a W alloy member with
coating of Non Non 258 60 m Satisfactory Invention, a metal-based
self-lubricating composite material Complete obtained by dispersing
WS.sub.2 + BN to W alloy, applied casting to the inner wall by
plating. 14 The Present Mold composed of a ceramic member obtained
by Frequency Non 258 60 m Satisfactory Invention, sintering sialone
(30 vol %) and BN (70 vol %), with 5 kHz Complete coating of BN
applied to the inner wall by CVD. Amplitude casting 5 .mu.m 15 The
Present Mold composed of a ceramic member obtained by Non MoS.sub.2
fine 258 60 m Satisfactory Invention, sintering sialone (30 vol %)
and BN (70 vol %), with particle + Mineral Complete coating of BN
applied to the inner wall by CVD. oil casting 16 The Present Mold
composed of a ceramic member obtained by Frequency MoS.sub.2 fine
258 60 m Satisfactory Invention, sintering sialone (30 vol %) and
BN (70 vol %), with 5 kHz particle + Mineral Complete coating of BN
applied to the inner wall by CVD. Amplitude oil casting 5 .mu.m 17
The Present Mold composed of a W alloy member with coating of
Frequency Non 258 60 m Satisfactory Invention, a metal-based
self-lubricating composite material 5 kHz Complete obtained by
dispersing WS.sub.2 + BN to W alloy, applied Amplitude casting to
the inner wall by plating. 5 .mu.m 18 The Present Mold composed of
a W alloy member with coating of Non MoS.sub.2 fine 258 60 m
Satisfactory Invention, a metal-based self-lubricating composite
material particle + Mineral Complete obtained by dispersing
WS.sub.2 + BN to W alloy, applied oil casting to the inner wall by
plating. 19 The Present Mold composed of a W alloy member, with
coating of Frequency MoS.sub.2 fine 258 60 m Satisfactory
Invention, a metal-based self-lubricating composite material 5 kHz
particle + Mineral Complete obtained by dispersing WS.sub.2 + BN to
W alloy, applied Amplitude oil casting to the inner wall by
plating. 5 .mu.m
[0098] [Table 2] TABLE-US-00002 TABLE 2 Vertical Forced Average
vibration of lubrication casting speed Casting Quality of slab No.
Mold mold of mold (mm/min) length (m) surface 20 The Present Mold
composed of a combination of a part of a glassy Non Non 258 60 m
Excellent Invention, carbon member including the inner wall in the
Complete solidification starting position and another part casting
of a graphite member with bulk density of 1.82. 21 The Present Mold
composed of a combination of a part of a Non Non 258 60 m
Satisfactory Invention, layered carbon member including the inner
wall in Complete the solidification starting position and another
casting part of a graphite member with bulk density of 1.82. 22 The
Present Mold composed of a combination of a part of a BN Non Non
258 60 m Satisfactory Invention, member including the inner wall in
the Complete solidification starting position and another part
casting of a ceramic member obtained by sintering sialone (30 vol
%) and BN (70 vol %). 23 The Present Mold composed of a combination
of a part of a Non Non 258 60 m Satisfactory Invention metal-based
self-lubricating composite member Complete obtained by dispersing
WS.sub.2 + BN (85 vol %) to W alloy, casting including the inner
wall in the solidification starting position, and another part of a
Cu--Cr alloy member. 24 The Present Mold composed of a combination
of an upper stream Non Non 258 60 m Excellent Invention, part of a
graphite member with bulk density of 1.82 Complete with a coating
of a glassy carbon material, and casting another down stream part
of a metal-based self-lubricating composite member obtained by
dispersing WS.sub.2 + BN (85 vol %) to W alloy. 25 The Present Mold
composed of a combination of an upper stream Non Non 258 60 m
Satisractory Invention, part of a graphite member with bulk density
of 1.82 Complete with a coating of a layered carbon material, and
casting another down stream part of a metal-based self-lubricating
composite member obtained by dispersing WS.sub.2 + BN (85 vol %) to
W alloy. 26 The Present Mold composed of a combination of a part of
a Non Non 258 60 m Satisfactory Invention, ceramic member obtained
by sintering sialone Complete (30 vol %) and BN (70 vol %) with a
CVD coating of casting BN, and another part of a graphite member
with bulk density of 1.82. 27 The Present Mold composed of a
combination of a part of a W Non Non 258 60 m Satisfactory
Invention, alloy member obtained by dispersing WS.sub.2 + BN to W
Complete alloy with a plate coating of a metal-based casting
self-lubricating composite material, and another part of a graphite
member with bulk density of 1.82. 28 The Present Mold composed of a
metal-based self-lubricating Non Non 258 60 m Satisfactory
Inventiion, composite member obtained by dispersing WS.sub.2 + BN
Complete (85 vol %) to W alloy followed by sintering with a casting
frame coating of ZrO.sub.2--8 wt % Y.sub.2O.sub.3 applied to the
inner wall in the upper stream position including the
solidification starting position. 29 The Present Mold composed of a
W alloy member with a plate Non Non 258 60 m Satisfactory
Invention, coating of a metal-based self-lubricating composite
Complete material obtained by dispersing WS.sub.2 + BN to W alloy
casting applied to the inner wall in the solidification starting
position and with a sprayed ZrO.sub.2--8 wt % Y.sub.2O.sub.3
applied to the inner wall in the upper stream position including
the solidification starting position. 30 The Present Mold composed
of a combination of an upstream part Non Non 258 60 m Satisfactory
Invention, of a W alloy member with a plate coating of a Complete
metal-based self-lubricating composite material casting obtained by
dispersing WS.sub.2 + BN to W alloy applied to the inner wall in
the solidification starting position, and with a sprayed
ZrO.sub.2--8 wt % Y.sub.2O3 applied to the inner wall in the upper
stream position including the solidification starting position, and
a downstream part of a graphite member with bulk density of 1.83.
34 Comparative Mold composed of a natural graphite member. Non Non
258 3 m Frequent Interrupt of occurrence of pulling out pulling out
due to slab mark crack failure 35 Comparative Mold composed of a
graphite member with bulk Non Non 258 3 m Frequent density of 1.77.
Interrupt of occurrence of pulling out pulling out due to slab mark
crack failure 36 Comparative Mold composed of graphite member with
bulk Non Non 258 4 m Frequent density of 1.82. Interrupt of
occurrence of pulling out pulling out due to slab mark crack
failure 37 Comparative Mold composed of a graphite member with bulk
Non Non 258 8 m Frequent density of 1.90. Interrupt of occurrence
of pulling out pulling out due to slab mark crack failure
[0099] The casting was intended to ensure a length of about 60 m
upon completion. However, due to an abnormal rise of pulling out
resistance because of mold biting in the initial solidification
shell was observed in some cases in the middle of the pulling out.
The quality of the slab surface was evaluated by visually
determining flaws thereon.
[0100] It is apparent from Tables 1 and 2 that the complete casting
was successful in the present invention with good quality. However,
in the comparative, complete casting could not be performed and the
quality was not acceptable to commercial work.
EXAMPLE B
[0101] There are 34 kinds of Cu alloys of the chemical compositions
shown in Table 3, which were smelted similarly to Example A. A
continuous casting test was carried out while varying the
production condition, and they were evaluated in the same method as
Example A. The results are shown in Tables 4 and 5. A satisfactory
result was obtained in any mold, any casting condition and any
chemical composition in the present invention. In contrast, an
unsatisfactory result for quality was obtained using comparative
molds. TABLE-US-00003 TABLE 3 Alloy No. Ti Cr Zr Ag Sn Mn Co Si Mg
Fe Al Zn Ni P Others 1 -- 0.39 2.95 -- -- -- -- -- -- -- -- -- --
-- -- 2 2.01 0.40 -- 0.25 -- -- -- -- -- -- -- -- -- -- Mg: 0.1,
Ca: 0.1 3 1.02 .20 0.99 -- -- -- -- -- -- -- -- -- -- -- -- 4 2.99
1.01 -- -- -- -- -- -- -- -- -- -- -- -- -- 5 -- 0.99 3.99 -- -- --
-- -- -- -- -- -- -- -- -- 6 -- 2.00 0.12 -- -- -- -- -- -- -- --
-- -- -- Li: 0.1, Sc: 0.5 7 0.98 1.97 -- 5.00 -- -- -- -- -- -- --
-- -- -- -- 8 3.01 -- 2.01 -- -- -- -- -- -- -- -- -- -- -- -- 9
1.01 4.00 -- 0.10 -- -- -- -- -- -- -- -- -- -- -- 10 5.00 0.99 --
-- -- -- -- -- -- -- -- -- -- 0.001 Nb: 0.2, Ge: 2.0 11 3.01 0.97
-- -- 0.41 -- -- 0.49 -- -- 0.51 -- -- Hf: 1.0, Bi: 0.5 12 -- 0.98
1.99 -- 0.10 -- -- 0.20 1.00 -- -- 0.21 -- -- -- 13 1.98 0.99 -- --
0.35 -- -- 0.04 -- -- 0.29 -- 1.50 0.001 Sb: 1.1 14 0.50 0.99 0.05
-- -- -- -- -- -- 2.00 0.21 0.50 -- 0.001 -- 15 2.02 1.01 0.49 --
2.01 -- -- -- -- 0.51 -- 0.26 0.01 0.120 -- 16 3.01 -- 0.72 0.01
0.29 -- -- 0.41 -- 0.32 -- 0.01 -- -- Ta: 0.5, Se: 0.2 17 1.98 0.99
-- -- 0.39 -- -- -- -- -- -- 0.40 -- -- -- 18 -- 1.03 1.93 -- 1.01
-- -- 0.01 -- 0.01 -- -- 0.150 -- 19 1.95 1.01 -- -- 0.35 -- 0.20
-- -- -- 0.21 1.01 -- -- Mo: 0.3, W: 0.05 20 -- 1.01 2.00 -- 0.40
0.01 0.01 0.11 -- -- 0.15 -- -- -- -- 21 1.98 0.50 -- -- 0.19 --
0.33 0.48 0.01 -- -- 0.01 0.05 -- Y: 1.8, Nd0.8, Ce0.4 22 4.01 0.98
-- -- -- -- 0.19 0.31 -- -- -- 0.21 0.45 -- -- 23 2.02 0.29 -- --
-- 2.00 0.45 -- -- -- 0.11 0.11 -- -- 24 1.99 0.99 0.52 -- -- -- --
0.39 -- -- -- -- 0.81 -- V: 0.5, In: 1.2 25 1.98 1.01 -- -- -- 0.01
-- 0.05 -- -- 0.01 -- -- -- -- 26 -- 0.98 2.01 0.25 -- 0.50 -- 0.79
-- 0.01 -- 0.46 -- -- -- 27 2.02 -- 0.98 -- -- 0.55 0.39 2.00 -- --
-- -- -- -- Te: 0.4, Sr: 3.2, B: 0.5 28 3.01 1.03 -- -- -- 2.00 --
0.50 -- 0.01 -- -- -- -- -- 29 -- 1.02 2.02 -- -- -- 1.00 0.20 --
0.20 0.09 -- 0.15 -- -- 30 1.99 3.03 -- -- 0.01 -- 0.48 -- -- --
2.00 -- 0.35 -- B: 0.01, Nb2.0 31 3.99 0.10 3.00 -- -- -- -- 0.10
0.05 -- -- -- -- -- -- 32 1.99 1.00 -- -- -- -- -- -- -- -- -- 3.00
-- 0.003 -- 33 -- 0.98 5.00 2.00 -- -- -- -- -- -- -- -- 3.00 --
Gd: 1.0, Mm: 2.0 34 2.01 1.02 1.01 -- -- -- -- 0.11 -- 0.10 -- --
-- -- B: 1.0
[0102] [Table 4] TABLE-US-00004 TABLE 4 Average Vertical Forced
casting Test Alloy vibration lubrication speed(mm/ Casting Quality
No. No. Mold of mold of mold min) length (m) of slab 38 The present
1 Mold composed of a graphite member with bulk density of Non Non
258 60 m Excellent invention, 1.83, with a coating of a glassy
carbon material applied to Complete the inner wall in the
solidification starting position. casting 39 The present 2 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position.. casting 40 The present 3 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 41 The present 4 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 42 The
present 5 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 43 The present 6 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 44 The present 7 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 45 The present 8 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 46 The
present 9 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 47 The present 10 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 48 The present 11 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 49 The present 12 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 50 The
present 13 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 51 The present 14 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 52 The present 15 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 53 The present 16 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 54 The
present 17 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 55 The present 18 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 56 The present 19 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 57 The present 20 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 58 The
present 21 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting
[0103] [Table 5] TABLE-US-00005 TABLE 5 Forced Average Vertical
lubri- casting Alloy vibration cation speed Casting Quality No. No.
Mold of mold of mold (mm/min) length (m) of slab 59 The present 22
Mold composed of a graphite member with bulk density of Non Non 258
60 m Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidilication
starting position. casting 60 The present 23 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 61 The present 24 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 62 The
present 25 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 63 The present 26 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 64 The present 27 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 65 The present 28 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 66 The
present 29 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 67 The present 30 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 68 The present 31 Mold composed of a
graphite member with bulk density of Non Non 258 60 m Excellent
invention, 1.83, with a coating of a glassy carbon material applied
to Complete the inner wall in the solidification starting position.
casting 69 The present 32 Mold composed of a graphite member with
bulk density of Non Non 258 60 m Excellent invention, 1.83, with a
coating of a glassy carbon material applied to Complete the inner
wall in the solidification starting position. casting 70 The
present 33 Mold composed of a graphite member with bulk density of
Non Non 258 60 m Excellent invention, 1.83, with a coating of a
glassy carbon material applied to Complete the inner wall in the
solidification starting position. casting 71 The present 34 Mold
composed of a graphite member with bulk density of Non Non 258 60 m
Excellent invention, 1.83, with a coating of a glassy carbon
material applied to Complete the inner wall in the solidification
starting position. casting 73 The present 3 Mold composed of a
combination of a part of a glassy Non Non 258 60 m Excellent
invention, carbon member including the solidification starting
Complete position, and another part of a graphite member with bulk
casting density of 1.83. 74 The present 3 Mold composed of a
combination of a part of a layered Non Non 258 60 m Satisfactory
invention, carbon member including the solidification starting
Complete position, and another part of a graphite member with bulk
casting density of 1.83. 75 Comparative 3 Mold composed of a
graphite member with bulk density Non Non 258 4 m Frequent 1.82.
Interrupt occurrence of pulling of pulling out due to out mark slab
failure crack 76 Comparative 4 Mold composed of a graphite member
with bulk density Non Non 258 4 m Frequent 1.82. Interrupt
occurrence of pulling of pulling out due to out mark slab failure
crack 77 Comparative 11 Mold composed of a graphite member with
bulk density Non Non 258 4 m Frequent 1.82. Interrupt occurrence of
pulling of pulling out due to out mark slab failure crack 78
Comparative 12 Mold composed of a graphite member with bulk density
Non Non 258 4 m Frequent 1.82. Interrupt occurrence of pulling of
pulling out due to out mark slab failure crack
EXAMPLE C
[0104] For the three kinds of alloys shown in Table 6, slabs of 20
mm.times.200 mm section were casted by use of a mold composed of
graphite with bulk density of 1.82, with a glassy carbon applied to
the inner wall, and the influence of the cooling rate on
characteristics was examined by varying the water quantities of
primary cooling and secondary cooling, and varying the cooling rate
from the solidification start point to 600.degree. C. The cooled
slabs were cold rolled to 3 mm, then aged at 400.degree. C. for 2
hr under an inert gas atmosphere followed by cold rolling to 0.5
mm, and finally aged at 350.degree. C. for 6 hr. The electric
conductivity and tensile strength by tensile test of the resulting
test materials were evaluated by the following methods.
[0105] [Table 6] TABLE-US-00006 TABLE 6 Alloy Cooling No. Ti Cr Zr
rate(.degree. C./s) TS(MPa) IACS(%) Evaluation* Remarks Comparative
35 2.00 1.51 -- 0.10 -- -- X Not evaluated because of cracking
during cold rolling The present 35 2.01 1.51 -- 0.50 802 40
.largecircle. invention 35 1.98 1.49 -- 5.00 956 27 .largecircle.
35 1.99 1.51 -- 10.00 1174 19 .largecircle. Comparative 36 -- 1.50
2.02 0.10 420 65 X The present 36 -- 1.50 2.04 0.50 750 52
.largecircle. invention 36 -- 1.49 1.99 5.00 872 48 .largecircle.
36 -- 1.48 2.00 10.00 1012 35 .largecircle. Comparative 37 1.51 --
1.49 0.10 -- -- X Not evaluated because of cracking during cold
rolling The present 37 1.53 -- 1.50 0.50 892 35 .largecircle.
invention 37 1.49 -- 1.49 5.00 1015 24 .largecircle. 37 1.52 --
1.48 10.00 1230 17 .largecircle. Note: *.largecircle. means
satisfying equation (1)
<Tensile Strength>
[0106] A test piece 13 B, according to the regulation of JIS Z
2201, was collected from each specimen, and the tensile strength
[TS (MPa)] at room temperature (25.degree. C.) was determined
according to the method regulated in JIS Z 2241.
<Electric Conductivity>
[0107] A test piece with width of 10 mm.times.length of 60 mm was
prepared from each specimen, current was carried in the
longitudinal direction of the test piece in order to measure the
potential difference between both ends of the test piece, and the
electric resistance was determined by a 4-terminal method.
Successively, the electric resistance (resistivity) per unit volume
was calculated from the volume of the test piece that was measured
by a micrometer, and the electric conductivity [IACS (%)] was
determined from its ratio to resistivity 1.72 .mu..OMEGA.cm of a
reference sample obtained by annealing polycrystalline pure
copper.
[0108] In case of having a cooling rate lower than 0.5.degree. C./s
according to the comparative, cracking was caused in cold rolling,
and even if cold rolling could be performed, the balance between
strength and electric conductivity was poor. On the other hand, the
balance between both was satisfactory and the high tensile strength
in relation with the high electric conductivity is provided
according to the present invention,
[0109] The "high tensile strength in relation with conductivity"
means a state satisfying the following equation (1) (this state is
hereinafter referred to as "well-balanced state of tensile strength
and electric conductivity"):
TS.gtoreq.k.sub.10+k.sub.11exp(-k.sub.12IACS) (1)
[0110] wherein TS: tensile strength (MPa), IACS: electric
conductivity (%), k.sub.10=658.06, k.sub.11=985.48, and
k.sub.12=0.0513.
[0111] IACS means the percentage to the electric conductivity of
the pure copper polycrystalline material.
[0112] Further, characteristics of the alloys shown in Table 3 were
similarly evaluated in the above-mentioned casting condition while
setting the cooling rate 5.degree. C./s from the solidification
start to 600.degree. C. The result is shown in Table 7. As a
result, each alloy has the balance between strength and
conductivity satisfying the above equation (1), and a satisfactory
result was obtained by the present invention.
[0113] [Table 7] TABLE-US-00007 TABLE 7 Alloy No. TS (MPa) IACS (%)
1 800 45 2 1145 25 3 967 32 4 1281 20 5 820 45 6 668 79 7 965 36 8
1279 19 9 970 40 10 1469 8 11 1286 15 12 960 33 13 1143 21 14 862
36 15 1139 20 16 1288 14 17 1145 18 18 980 28 19 1138 21 20 965 29
21 1135 19 22 1386 9 23 1140 17 24 1152 18 25 1142 16 26 972 33 27
1141 20 28 1279 15 29 992 28 30 1137 20 31 1385 14 32 1145 19 33
1002 30 34 1149 18
INDUSTRIAL APPLICABILITY
[0114] The present invention involves a continuous casting mold
used mainly for a direct-connection type of continuous casting,
with a mold directly connected to a holding furnace, and a
continuous casting method of a Cu alloy. Namely, the present
invention provides a mold capable of continuously and efficiently
producing a sound slab or bloom, and also a continuous casting
method of a Cu alloy which ensures excellent characteristics, such
as strength, electric conductivity, vending workability, impact
resistance and fatigue strength of the final product after working
and heat treatment. Particularly, the application of the production
of the Cu alloy containing elements such as Zr, Ti, Cr, Ta and V
that easily generate carbides provides a profound effect.
BRIEF DESCRIPTION OF THE FIGURES
[0115] [FIG. 1] An example of a continuous casting mold according
to the present invention.
[0116] [FIG. 2] An example of the continuous casting mold according
to the present invention, which has a coating 8 of a self-lubricant
or a metal-based self-lubricating composite material applied to the
mold inner wall in the solidification starting position of a Cu
alloy melt.
[0117] [FIG. 3] An example of the continuous casting mold according
to the present invention, which is composed of a plurality of parts
of mold members.
[0118] [FIG. 4] An example of the continuous casting mold according
to the present invention, which is composed of a plurality of parts
of mold members, and has a coating 8 of a self-lubricant or
metal-based self-lubricating composite material applied to the mold
inner wall in the solidification starting position of an alloy
melt.
[0119] [FIG. 5] Another example of the continuous casting mold
according to the present invention, which includes a coating 9 of
ceramic material applied to the inner wall in the position that
contacts with a Cu alloy melt in order to inhibit the reaction with
the melt.
[0120] [FIG. 6] Another example of the continuous casting mold
according to the present invention, which has a coating 8 of a
metal-based self-lubricating composite material applied to the mold
inner wall in the solidification starting position of an alloy
melt, and a coating 9 of a ceramic material applied to the inner
wall in the position that contacts with a Cu alloy melt in order to
inhibit reaction with the melt.
[0121] [FIG. 7] Another example of the continuous casting mold
according to the present invention, which is composed of an
upstream part of a metal member and a downstream part of a graphite
member, with a coating 8 of a metal-based self-lubricating
composite material applied to the inner wall in the solidification
starting position of an alloy melt, and with a coating 9 of a
ceramic material applied to the inner wall in the position that
contacts with a Cu alloy melt in order to inhibit the reaction with
the melt.
[0122] [FIG. 8] A phase diagram of a Ti--Cr alloy.
[0123] [FIG. 9] A phase diagram of a Zr--Cr alloy.
[0124] [FIG. 10] A phase diagram of a Ti--Zr alloy.
EXPLANATION OF REFERENCE NUMERALS
[0125] 1. Cu alloy melt [0126] 2. Holding furnace wall [0127] 3.
Mold member [0128] 3'. Another part of mold member [0129] 4: Slab
[0130] 5. Cooling jacket [0131] 6. Secondary cooling [0132] 7.
Pulling out direction [0133] 8. Coating to the inner wall in the
solidification starting position of a Cu alloy melt [0134] 9.
Coating to the inner wall on the position that contacts with a Cu
alloy melt [0135] 10. Solidification starting position of a Cu
alloy melt
* * * * *