BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] This invention relates to the technical field of metal making and processing using
the continuous casting process. More specifically, this invention pertains to an improved
mold surface for a continuous casting machine, and to a system and method for controlling
the casting process by actually monitoring the temperature of the casting at the mold
surface while the machine is operating.
2. Description of the Prior Art and the Related Technology
[0002] Production of metals by use of the continuous casting technique has been increasing
since its large-scale introduction about thirty years ago, and now accounts for a
large percentage of the volume of steel, among other metals, produced each year worldwide.
It is well known that continuous casting machines typically include a mold that has
two essentially parallel and opposed wide walls, and two essentially parallel opposed
narrow walls that cooperate with the wide walls to define a casting passage of rectangular
cross section. Molten metal is supplied continuously into a top end of the casting
passage, and the mold is designed to cool the metal so that an outer skin forms before
the so-formed slab or strand exits a bottom of the casting passage. In order to efficiently
dissipate the heat from the molten steel, the mold casting surfaces are typically
lined with copper or have a copper alloy surface layer and contain numerous passages
through which water flows, during the molding process for rapid heat exchange. In
some instances, the mold is cooled by spraying water directly against the cooler side
of the mold liner. The strand is further cooled by spraying as it travels away from
the mold, until it becomes completely solidified. It may then be processed further
into an intermediate or finished metal product, such as steel plate, sheeting or coils
by traditional techniques such as rolling.
[0003] The mold casting surfaces, also known as the "hot faces" of the mold, are exposed
to the high temperature molten steel and corrosive mold flux for prolonged periods
of time. Copper is a very efficient thermal conductor, but is relatively soft and
is thus susceptible to early wear and other types of degradation. Under normal casting
conditions, the hot faces of the mold experience relatively rapid degradation such
as wear, cracking and steam and chemical erosion. This effect is exacerbated in high-speed
molds, which tend to run at higher temperatures wherein the copper material begins
to further soften. The assignee of this invention, A.G. Industries, Inc., is the largest
North American provider of maintenance and repair services for continuous casting
machines, and is intimately familiar with the degradation and wear that occurs on
mold faces during casting.
[0004] In order to prolong the life of the mold surfaces for as long as possible, it is
typical to pre-coat the copper mold surface with a friction and corrosion resistant
material, such as such as nickel or chromium. Other techniques for protecting the
mold wall surfaces have been proposed and/or put into commercial use. For example,
U.S. Patent 5,499,672 discloses a process for protecting a copper mold surface by
applying a metal carbide protective material onto the mold surface. Another protective
coating technique involves applying a Ni-Cr alloy to the copper mold faces by a thermal
spraying process. This process is described in the publication
Ni-Cr Alloy Thermal Spraying of the Narrow Face of Continuous Casting Mold, dated May 1989 by Nippon Steel Corporation and Mishima Kosan Co., Ltd. While the
coatings that have been developed to date have been able to reduce the rate and severity
of mold wear to some extent, it remains a fact of life in the continuous casting industry
that the mold faces must be periodically removed and replaced or repaired. Taking
the mold off line to do this represents a significant cost to a steelmaker, perhaps
as much as fifteen thousand dollars per hour.
[0005] The strand or slab has a very thin skin when it initially forms in the mold. Rupture
of the skin must be avoided at all costs because it can cause a condition known as
a breakout, i.e., where molten metal escapes through the skin beneath the mold. A
severe breakout can encase portions of the machine that are in its path in molten
metal, rendering those components unusable and requiring them to be replaced and reconditioned.
One of the factors that is important in determining whether or not a breakout is likely
to occur is the thickness of the skin as the casting moves though the mold. Theoretically,
skin thickness could be measured
in situ during casting by monitoring the infrared emissions of the slab, but in practice
this has not been feasible because the entire slab is surrounded by the mold, making
measurement impossible. Some systems exist that attempt to model the casting thickness
by sampling temperatures at selected locations in the mold liner; but these systems
can be less than accurate because of the varying thickness of the copper material
between the sensors and the casting surface.
[0006] JP 62 130748 discloses a water-cooled mold with a ceramic liner to improve wear resistance
and durability. The inold's liner is composed of boron nitride of a thermal conductivity
greater than or equal to 50 W/mK. The mold is not in the field of continuous casting
however. A mold for casting aluminium is shown in WO98/16335 and consists of mold
wall assemblies having an inner portion arranged to conduct heat away from the mold
liner, and an outer portion coated with boron nitride or diamond.
[0007] A need exists for a continuous casting mold that permits improved monitoring of the
casting as it moves through the mold so that breakouts and other unwanted conditions
can be prevented.
SUMMARY OF THE INVENTION
[0008] It is an object of the invention to provide a continuous casting mold that permits
improved monitoring of the casting as it moves through the mold so that breakouts
and other unwanted conditions can be prevented.
[0009] In order to achieve the above and other objects of the invention, an improved mold
wall assembly for use in a continuous casting machine is provided as defined in claim
1 below. A preferred embodiment comprising continuous casting machine is defined in
claim 7. According to a further aspect of the invention, there is provided a method
of making a strand of continuously cast material in accordance with claim 8 below.
[0010] For a better understanding of the invention, its advantages, and the objects obtained
by its use, reference should be made to the drawings which form a further part hereof,
and to the accompanying descriptive matter, in which there is illustrated and described
a preferred embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011]
FIGURE 1 is a fragmentary horizontal cross-sectional view taken through a mold wall
assembly for a continuous casting machine that is constructed according to a preferred
embodiment of the invention;
FIGURE 2 is a vertical cross-sectional view taken through one component of the assembly
shown in FIGURE 1;
FIGURE 3 is a diagrammatical view of a preferred feature in the assembly shown in
FIGURES 1 and 2;
FIGURE 4 is a schematic diagram depicting a preferred control system for the assembly
shown in FIGURES I through 3;
FIGURE 5 is a fragmentary vertical cross-sectional view taken through a mold wall
assembly that is constructed according to a second embodiment of the invention; and
FIGURE 6 is a fragmentary vertical cross-sectional view taken through a mold wall
assembly that is constructed according to a third embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0012] Referring now to the drawings, wherein like reference numerals designate corresponding
structure throughout the views, and referring in particular to FIGURE 1, an improved
mold wall assembly 12 for a continuous casting machine 10 includes a plurality of
mold walls, including an opposing pair 14, 16 of narrowface walls and an opposing
pair of broadface walls 18,20. Each of the mold walls 14, 16, 18, 20 has at least
one mold surface that together define a casting space 26 having an upper opening and
a lower opening. The mold wall assembly 12 is designed, as is conventional, so that
molten metal can be supplied continuously into the top end of the casting space 26,
and so as to cool the metal so that an outer skin forms before the so-formed slab
or strand exits a bottom of the casting passage. As is conventional, coolant supply
pipes 22, 24 are provided for providing a water coolant to the narrowface walls 14,
16 and the broadface walls 18, 20, respectively.
[0013] Referring now to FIGURE 2, which is a vertical cross-sectional view taken through
one of the broad face walls 20 in FIGURE 1, it will be seen that wall 20 includes
a liner assembly 27 that bears the mold face 28, and a support assembly 32 to which
the liner assembly 27 is secured. As may be seen in FIGURE 2, the liner assembly 27
includes an inner portion 29 that is embodied as a copper liner 30, and an outer layer
44 of degradation-resistant, non-metallic material that forms the mold face 28, and
will be discussed in greater detail below. The support assembly 32 includes the coolant
supply pipe 24, a coolant return pipe 42, an inlet plenum 36 and an outlet plenum
38. Both the inlet and outlet plenums 36, 38 are in communication with a cooling channel
34 that is defined in the copper liner 30 of the liner assembly 27. In operation,
as is conventional, the coolant, which is typically water, is introduced from the
coolant supply pipe 24 into the inlet plenum 36, where it flows upwardly through the
cooling channel 34 and out into the outlet plenum 38. The coolant is then returned
to a circulation pump through the return pipe 42.
[0014] The layer 44 of degradation-resistant, non-metallic material is diamond or cubic
boron nitride. These materials preferably a are efficient conductors of heat, that
are very hard and degradation-resistant, that can tolerate the high temperatures that
exist in a continuous casting mold during operation, that are resistant to the acidic
environment in which a continuous casting machine typically functions, and that, for
reasons discussed in greater detail below, are transparent in the infrared portion
of the spectrum.
[0015] Diamond is a allotrope of carbon that is metastable at ordinary pressures, having
a large activation energy barrier that prevents conversion to graphite, the more stable
allotrope at ordinary temperatures and pressures. It has long been sought after not
only for its intrinsic beauty and value as a gemstone but also for its many unique
and valuable mechanical, electrical, optical and thermal properties. Diamond is the
hardest material occurring in nature, has a low co-efficient of friction, is extremely
resistant to chemical attack, is optically transparent to much of the electromagnetic
spectrum, including being highly transparent to infrared radiation, and has the highest
heat conductivity of any material. Cubic boron nitride (CBN) has properties that are
comparable to diamond in many respects.
[0016] One advantageous feature of the invention is depicted diagrammatically in FIGURE
3. As may be seen in FIGURES 2 and 3, a passage 46 is formed in the copper liner plate
30 of the liner assembly 27. An optical fiber 48 is situated in the passage 46, and
is optically coupled to the transparent layer 34 of degradation-resistant, non-metallic
material on a side thereof that is opposite to the casting surface or mold face 28
of the layer 44. A sensor 50 is then coupled to a second, opposite end of the optical
fiber 48. The purpose of the sensor 50 is to monitor a property of the continuous
casting process by examining the spectral characteristics of the light that is carried
through the optical fiber 48. In its preferred embodiment, sensor 50 is constructed
and arranged to monitor the infrared profile of the transmitted light, so as to monitor
the temperature of the exterior of the cast strand as it moves downwardly along the
casting surface within the mold. By monitoring this temperature, the thickness of
the skin of the casting can be determined, which is a useful indicator for many things,
including the susceptibility of the strand to breakouts after it exits the bottom
of the mold, the optimal withdrawal speed of the strand from the machine, the optimal
rate at which coolant is circulated through the mold walls, and the uniformity of
shell growth. Referring now to FIGURE 4, it will be seen that a number of such sensors
50 are provided in the mold assembly, and that each of those sensors provides information
to a CPU 52 that serves as a local control system for the mold wall assembly 12. CPU
52 is in two-way communication with a main control system 54 of the continuous casting
machine 10, and is further in communication with different subsystems for modifying
different performance variables of the continuous casting process. FIGURE 4 depicts
four such subsystems 56, 58, 60 , 62, but the number could be more or less, depending
upon the number of performance variables that are desired to be controlled in response
to the optical monitoring that is performed by the sensor 50. For example, one of
the subsystems may permit adjustment of the withdrawal speed of the continuous casting
machine. Another subsystem may permit adjustment of the taper of the mold. Third and
fourth subsystems for adjusting the rate of cooling the mold may constitute a control
system for adjusting the volumetric flow of coolant through one or more of the mold
walls, or changing the composition of mold flux for changing the heat conduction properties
of the mold.
[0017] In order to analyze the data that is gathered by the sensors 50, a commercially available
thermal imaging system may be used. One such imaging system that could be used is
available from Mikron Instruments of Oakland, New Jersey and is sold as an "Imaging
Pyrometer." This system is disclosed in part in U.S. Patent 4,687,344, the disclosure
of which is hereby incorporated as if set forth fully herein.
[0018] Looking now to FIGURE 5, a mold assembly 64 that is constructed according to a second
embodiment of the invention includes a casting surface 66, and a body 68 that is fabricated
entirely of the non-metallic, degradation-resistant material of the type that is discussed
in detail above. A cooling channel 70 is defined in the body 68 of material, and a
sensor 72, which is similar in construction to the sensor 50 discussed above, is coupled
to a rear side of the body 68. In this embodiment of the invention, the entire mold
wall is made of the diamond or CBN material. It is believed that this embodiment holds
great potential for the future, because such a mold wall would be expected to substantially
outperform any mold wall that is in service today. Fabricated entirely of a material
such as diamond, it would be much more efficient at conducting heat away from the
strand during casting than a metallic mold wall would, it would exhibit lower friction
than any metallic mold wall would, and it would be virtually indestructible in terms
of wear.
[0019] FIGURE 6 depicts yet another embodiment of the invention. In this embodiment, as
in the embodiment that is described above in reference to FIGURE 5, the entire mold
liner 80 is fabricated from a degradation-resistant nonmetallic material that has
high thermal conductivity, whereby the mold liner will exhibit superior wear and heat
transfer characteristics during its operation in a continuous casting machine. As
in the embodiment of FIGURE 5, the preferred materials are diamond or CBN, and the
mold liner can be constructed according to any of the fabrication processes disclosed
below, or by any other process that will be effective. A sensor 72, which is similar
in construction to the sensor 50 discussed above, is coupled to a rear side of the
mold liner 80. In this embodiment, the mold liner 80 does not have an internal cooling
passage, but is constructed as a "spray-type" mold in which the side 86 of the liner
that is opposite the casting 82 is subjected to cooling spray from one or more spray
nozzles 88. The high thermal conductivity of this type of mold liner will contribute
to the effective cooling of the casting and the formation of casting that has a uniform
solidified shell 84. In addition, a significant amount of heat will also be transferred
away from the casting by means of radiation as a result of the transparency of the
mold in the infrared range. This stands in favorable contrast to a conventional continuous
casting mold, where there is no heat transfer through the mold wall by means of radiation.
[0020] There are a number of known techniques for artificially building coatings and masses
of materials such as diamond and CBN, and the inventors recognize that any one of
those known techniques could be used within the purview of the invention. The inventors
further appreciate that this technology is advancing at a rapid rate, and expect to
be able to utilize other, more efficient techniques for creating the necessary structure
when such new technology becomes available. The following U.S. Patents and PCT Publications
disclose techniques for artificially building coatings and masses of materials such
as diamond and CBN, and are to be considered exemplary for purposes of this disclosure.
Each of the documents listed below are hereby incorporated into this disclosure as
if set forth fully herein:
U.S. Patent No. |
Name |
Publication Date |
4,490,229 |
Mirtich et al. |
12/23/94 |
4,504,519 |
Zelez |
3/12/85 |
4,770,940 |
Ovshinsky et al. |
9/13/88 |
4,830,702 |
Singh et al. |
3/16/89 |
4,910,041 |
Yanagihara et al. |
3/20/90 |
4,939,763 |
Pinneo et al. |
7/3/90 |
4.948,629 |
Hacker et al. |
8/14/90 |
4,954,365 |
Neifeld |
9/4/90 |
4,981,717 |
Thaler |
1/1/91 |
4,987,007 |
Wagal et al. |
1/22/91 |
5,015,528 |
Pinneo |
5/14/91 |
5,071,677 |
Patterson et al. |
12/10/91 |
5,080,753 |
Doll et al. |
1/14/92 |
5,082,359 |
Kirkpatrick |
1/21/92 |
5,096,740 |
Nakagama et al. |
3/17/92 |
5,154,945 |
Baldwin et al. |
10/13/92 |
5,221,411 |
Narayan |
6/22/93 |
5,221,501 |
Feldman et al. |
6/22/93 |
5,230,931 |
Yamazaki et al. |
7/27/93 |
5,236,740 |
Peters et al. |
8/17/93 |
5,243,170 |
Maruyama et al. |
9/7/93 |
5,260,106 |
Kawarada et al. |
11/9/93 |
5,264,071 |
Anthony et al. |
11/23/93 |
5,271,890 |
Shimura et al. |
11/21/93 |
5,273,731 |
Anthony et al. |
12/28/93 |
5,273,788 |
Yu |
12/28/93 |
5,302,231 |
Bovenkerk et al. |
4/12/94 |
5,516,500 |
Liu et al. |
5/14/96 |
5,525,815 |
Einset |
6/11/96 |
PCT App. No. |
Name |
Publication Date |
PCT/US95/05941 |
Mistry |
11/23/95 |
PCTIUS95/00782 |
Mistry |
??? |
Most Preferred Processes for Applying the Non Metallic Wear Resistant Layer
[0021] In one embodiment, which utilizes the process that is taught in U.S. Pat. No. 4,490,229,
a diamond-like carbon film can be deposited in the surface of a substrate by exposing
the surface to an argon ion beam containing a hydrocarbon. The current density in
the ion beam is low during initial deposition of the film. Subsequent to this initial
low current condition, the ion beam is increased to full power. At the same time a
second argon ion beam is directed toward the surface of the substrate. The second
ion beam has an energy level much greater than that of the ion beam containing the
hydrocarbon. This addition of energy to the system increases mobility of the condensing
atoms and serves to remove Lesser-bound atoms, increasing the percentage of diamond
bonds.
[0022] In a second embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,504,519, an amorphous, carbonaceous, diamond-like film is produced by a hybrid process
in a deposition chamber using a radio frequency plasma decomposition from an alkane,
such as n-butane, using a pair of spaced, generally parallel, carbon electrodes, preferably
ultra pure carbon electrodes. While most films of this invention were deposited using
normal butane, other alkanes, such as methane, ethane, propane, pentane, and hexane
can be substituted in the process of this invention to produce the improved carbonaceous,
diamond-like film thereof. The deposition chamber, such as a stainless steel chamber,
includes a pair of generally parallel and horizontal, vertically spaced, pure carbon
electrodes with the substrate to be coated positioned on the lower carbon electrode.
The electrodes are typically positioned about 2 up to about 8 centimeters apart from
each other, with the preferred electrode spacing being approximately 2.5 centimeters.
The chamber is evacuated to its ultimate pressure, generally in the region of about
10< - 7 > torr, and then backfilled with an alkane, such as n-butane, to a pressure
of approximately 8 x 10< - 4 > torr. Thereafter, the vacuum system is throttled to
a pressure in the range of approximately 25 to 100 millitorr. After stabilization
of the pressure, the radio frequency power is applied to the pair of pure carbon electrodes
with the lower electrode (substrate target) being biased in the range of about 0 to
about - 100 volts, and the upper electrode being biased in the range of about - 200
to about - 3500 volts. Radio frequency plasma decomposition is begun, and an amorphous,
carbonaceous, diamond-like film is deposited onto the substrate at rates varying between
about 8 up to 35 angstroms per minute, to produce a film of up to about 5 micrometers
in thickness.
[0023] In a third embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,770,940, a hard carbonaceous film is formed by decomposing a gaseous hydrocarbon
having carbon atoms tetrahedrally coordinated to its nearest neighbors through carbon-carbon
single bonds. The gaseous hydrocarbon is decomposed in a radio frequency maintained
plasma and the plasma decomposition products are deposited on a cathodic substrate.
Optionally, fluorocarbons may be present in a decomposition gas.
[0024] In a fourth embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,830,702, a hydrocarbon/hydrogen gas mixture is passed through a refractory metal
hollow cathode which is self heated to a high temperature. The gas mixture is dissociated
by a combination of thermal and plasma effects. The plasma plume emanating from the
hollow cathode heats the substrate, which is positioned on a surface of the anode.
Growth of the diamond film is enhanced by bombardment of electrons.
[0025] In a fifth embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,910,041, a film is formed on a substrate through a process of bringing a substrate
into contact with a plasma zone formed by generating, by use of a discharge electrode
or discharge electrodes, high temperature or quasi-high temperature plasma of a gas
containing at least one carbon-containing compound. The electrodes include a sheet-like
electrode provided with a slit having a linear portion and connected to a microwave
electric source. Alternatively, the plasma zone is formed by forcing a high temperature
or quasi-high temperature plasma generated in an arc between the electrodes to move
by applying a magnetic field. The process enables energy efficient formation of films
on substrate surfaces.
[0026] In a sixth embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,939,763, a synthetic diamond film may be formed by a D.C. plasma-assisted deposition
at 0.5 to 1.5 amperes plasma current at a temperature of 600 to 800 degrees C using
methane/ hydrogen (0.8-1 : 99.5-1 volume ratio) at a total pressure of 20-30 torr.
[0027] In a seventh embodiment, which utilizes the process that is taught in U.S. Pat. No.
4.948,629, diamond films are deposited at substrates below temperatures of 400 degrees
C. by chemical vapor deposition using a high powered pulsed laser and a vapor which
is an aliphatic carboxylic acid or an aromatic carboxylic anhydride.
[0028] In a eighth embodiment, which utilizes the process that is taught in U.S. Pat. No
4954365. a thin diamond film is prepared by immersing a substrate in a liquid containing
carbon and hydrogen and then subjecting the substrate to at least one laser pulse.
[0029] In an ninth embodiment, which utilizes the process that is taught in U.S. Pat. No.
4,981,717, a method of depositing diamond-like films produces depositing species from
a plasma of a hydrocarbon gas precursor. The plasma is generated by a laser pulse,
which is fired into the gas and is absorbed in an initiater mixed with the gas. The
resulting detonation produces a plasma of ions, radicals, molecular fragments and
electrons which is propelled by the detonation pressure wave to a substrate and deposited
thereon.
[0030] In a tenth embodiment, which utilizes the process that is taught in U.S. Pat. No
4,987,007 a method and apparatus is provided which produces a layer of material on
a substrate by extracting ions from a laser ablation plume in a vacuum environment.
In a basic embodiment, the apparatus includes a vacuum chamber containing a target
material and a laser focused on the target to ablate the material and ionize a portion
of the ablation plume. An accelerating grid within the vacuum chamber is charged to
extract the ions from the plume and direct the ions onto a substrate to grow the layer.
The basic embodiment has produced diamond-like carbon films on a clean, unseeded silicon
substrate at deposition rates approaching 20 microns per hour. The diamond-like carbon
films produced were of exceptional quality: uniform thickness with a surface roughness
about 1 Angstrom; uniform index of refraction within the range of 1.5-2.5; resistivity
greater than 40 megs ohms per centimeter; and a hard surface resistant to physical
abuse. An enhanced embodiment includes multiple targets within the vacuum chamber
and mechanisms to selectively produce ions from each target. Thus, layers of different
materials or doped materials can be made on the substrate. Additionally, the enhanced
embodiment includes a mechanism for making patterns or circuits within each layer.
One version incorporates a mask within the ion fluence and ion optics to magnify the
mask pattern onto the substrate. Another version uses ion optics to form an ion beam
and deflection plates controlling the ion beam to write the desired pattern on the
substrate.
[0031] In an eleventh embodiment, which utilizes the process that is taught in U.S. Pat.
No. 5,015,528, a process for forming synthetic diamond is utilized which involves
vapor deposition of a carbon gas source in the presence of atomic hydrogen on a substrate
contained in a fluidized bed. The diamond may be overcoated by vapor deposition of
a non-diamond material.
[0032] In a twelfth embodiment, which utilizes the process that is taught in U.S. Pat. No.
5,071,677, a method for depositing diamond films and particles on a variety of substrates
by flowing a gas or gas mixture capable of supplying (1) carbon, (2) hydrogen and
(3) a halogen through a reactor over the substrate material. The reactant gases may
be pre-mixed with an inert gas in order to keep the overall gas mixture composition
low in volume percent of carbon and rich in hydrogen. Pre-treatment of the reactant
gases to a high energy state is not required as it is in most prior art processes
for chemical vapor deposition of diamond. Since pre-treatment is not required, the
may be applied to substrates of virtually any desired size, shape or configuration.
The reactant gas mixture preferably is passed through a reactor, a first portion of
which is heated to a temperature of from about 400 degrees C. to about 920 degrees
C. and more preferably from about 800 degrees C. to about 920 degrees C. The substrate
on which the diamond is to be grown is placed in the reactor in a zone that is maintained
at a lower temperature of from about 250 degrees C. to about 750 degrees C., which
is the preferred diamond growth temperature range. The process preferably is practiced
at ambient pressures, although lower or higher pressures may be used. Significant
amounts of pure diamond films and particles have been obtained in as little as eight
hours. The purity of the diamond films and particles has been verified by Raman spectroscopy
and powder x-ray diffraction techniques.
[0033] In a thirteenth embodiment, which utilizes the process that is taught in U.S. Pat.
No. 5,080,753, thin films of single crystal, cubic phase boron nitride that is epitaxially
oriented upon a silicon substrate are formed using laser ablation techniques.
[0034] In a fourteenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,082,359, a method of forming a polycrystalline film, such as a diamond, on a foreign
substrate involves preparing the substrate before film deposition to define discrete
nucleation sites. The substrate is prepared for film deposition by forming a pattern
of irregularities in the surface thereof. The irregularities, typically craters, are
arranged in a predetermined pattern, which corresponds to that desired for the location
of film crystals. The craters preferably are of uniform, predetermined dimensions
(in the sub-micron and micron size range) and are uniformly spaced apart by a predetermined
distance. The craters may be formed by a number of techniques, including focused ion
beam milling, laser vaporization, and chemical or plasma etching using a patterned
photoresist. Once the substrate has been prepared the film may be deposited by a number
of known techniques. Films prepared by this method are characterized by a regular
surface pattern of crystals, which may be arranged in virtually any desired pattern.
[0035] In a fifteenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,096,740, a highly pure cubic boron nitride film is formed on a substrate by a method
which involves irradiating an excimer laser on a target comprising boron atoms and
optionally nitrogen atom and depositing cubic boron nitride on a substrate which is
placed to face the target.
[0036] In a sixteenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,154,945, infrared lasers are used to deposit diamond thin films onto a substrate.
In one embodiment, the deposition of the film is from a gas mixture of CH4 and H2
that is introduced into a chemical vapor deposition chamber and caused to flow over
the surface of the substrate to be coated while the laser is directed onto the surface.
In another embodiment, pure carbon in the form of soot is delivered onto the surface
to be coated and the laser beam is directed onto the surface in an atmosphere that
prevents the carbon from being burned to CO2.
[0037] In a seventeenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,221,411, a method for developing diamond thin films on a non-diamond substrate involves
implanting carbon ions in a lattice-plane matched or lattice matched substrate. The
implanted region of the substrate is then annealed to produce a diamond thin film
on the non-diamond substrate. Also disclosed are the diamond thin films on non-diamond
lattice-plane matched substrates produced by this method. Preferred substrates are
lattice and plane matched to diamond such as copper, a preferred implanting method
is ion implantation, and a preferred annealing method is pulsed laser annealing.
[0038] In a eighteenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,221,501, a method of producing transparent diamond laminates is used which employs
a substrate which is removed once a second layer is deposited over the diamond coating,
thereby exposing a smooth diamond surface. The second coating should have a refractive
index substantially identical to diamond, with zinc selenide and titanium dioxide
being particularly preferred. Diamond films having two smooth surfaces may be produced
by simultaneous deposition on parallel, opposed substrates until the two diamond films
merge together to form a single film or plate, followed by removal of at least a portion
of the two substrates.
[0039] In a nineteenth embodiment, which utilizes the process that is taught in U.S. Pat.
5,230,931, a diamond film or an I-Carbon film is formed on a surface of an object
by virtue of plasma-assisted chemical vapor deposition. The hardness of the films
can be enhanced by applying a bias voltage to the object during deposition.
[0040] In a twentieth embodiment, which utilizes the process that is taught in U.S. Pat.
5,236,740, a cemented tungsten carbide substrate is prepared for coating with a layer
of diamond film by subjecting the substrate surface to be coated to a process which
first removes a small amount of the tungsten carbide at the surface of the substrate
while leaving the cobalt binder substantially intact. Murakami's reagent is presently
preferred. The substrate is then subjected to a process, which removes any residue
remaining on the surface as a result of the performance of the process, which removes
the tungsten carbide. A solution of sulfuric acid and hydrogen peroxide is presently
preferred. A diamond coated cemented tungsten carbide tool is formed using an unpolished
substrate, which may be prepared by etching as described above or by etching in nitric
acid prior to diamond film deposition. Deposition of a substantially continuous diamond
film may be accomplished by reactive vapor deposition, thermally assisted (hot filament)
CVD, plasma-enhanced CVD, or other techniques.
[0041] In a twenty-first embodiment, which utilizes the process that is taught in U.S. Pat.
5,243,170, a method for providing a coating film of diamond on a substrate involves
the plasma jet deposition method, in which the deposited diamond film has, different
from the cubic crystalline structure formed under conventional conditions, a predominantly
hexagonal crystalline structure so as to greatly enhance the advantages obtained by
the diamond coating of the tool in respect of the hardness and smoothness of the coated
surface. The improvement comprises: using hydrogen alone as the plasma-generating
gas; controlling the pressure of the plasma atmosphere not to exceed 300 Torr; keeping
the substrate surface at a temperature of 800 degrees-1200 degrees C.; and making
a temperature gradient of at least 13,000 degrees C./cm within the boundary layer
on the substrate surface.
[0042] In a twenty-second embodiment, which utilizes the process that is taught in U.S.
Pat. 5,260,106, a diamond film is attached securely to the substrate by forming a
first layer on the surface comprising a mixture of a main component of the substrate
and a sintering reinforcement agent for diamond, then forming a second layer comprising
a mixture of said agent and diamond on said first layer, and finally forming the diamond
film on the second layer.
[0043] In a twenty-third embodiment, which utilizes the process that is taught in U.S. Pat.
5,264,071, the bond strength between a diamond and the substrate onto which it is
deposited by the chemical vaporization method is decreased to the point where the
diamond can be removed from the substrate as a free standing monolithic sheet. The
bond strength can be decreased by polishing the substrate, removing comers from the
substrate, slow cooling of the substrate after deposition, an intermediate temperature
delay in cooling or the application or formation of an intermediate layer between
the diamond and the substrate. The freestanding sheet of diamond is envisioned as
being of particular use for the embodiment of FIGURE 5.
[0044] In a twenty-fourth embodiment, which utilizes the process that is taught in U.S.
Pat. 5,271,890, a coating film of a carbon allotrope is formed on a substrate by continuously
supplying a fine carbon powder onto the substrate and simultaneously irradiating the
fine carbon powder with a laser beam of a high output level thereby inducing sublimation
of the fine carbon powder, and quenching the sublimated fine carbon powder to cause
deposition thereof on the substrate.
[0045] In a twenty-fifth embodiment, which utilizes the process that is taught in U.S. Pat.
5,273,731, a substantially transparent polycrystalline diamond film is made having
a thickness greater than 50 microns. A mixture of hydrogen and methane is conveyed
into a heat filament reaction zone, which is adjacent to an appropriate substrate,
such as a molybdenum substrate to produce non-adherent polycrystalline substantially
transparent diamond film.
[0046] In a twenty-sixth embodiment, which utilizes the process that is taught in U.S. Pat.
5,273,788, a layer of a hydrocarbon molecule is applied to a substrate by the Langmuir-Blodgett
technique, and the surface is irradiated with a laser to decompose the layer of molecules
at the surface without influencing the substrate. After decomposition the carbon atoms
rearrange on the surface of the substrate to form a DLC film.
[0047] In a twenty-seventh embodiment, which utilizes the process that is taught in U.S.
Pat. 5,302,231, a method for growing diamond on a diamond substrate by chemical vapor
deposition involves alternatingly contacting at elevated temperature said diamond
substrate with a gas having the formula Cn X m and then with a gas having the formula
C 1 Z p . X and Z each form single bonds with carbon. X and Z also are reactable to
form ZX or a derivative thereof. The Z-X bond is stronger than the C-X bond and also
is stronger than the C-Z bond. In the formulas, n, m, 1, and p are integers.
[0048] In a twenty-eighth embodiment, which utilizes the process that is taught in U.S.
Pat. 5,516,500, diamond materials are formed by sandwiching a carbon-containing material
in a gap between two electrodes. A high-amperage electric current is applied between
the two electrode plates so as cause rapid heating of the carbon-containing material.
The current is sufficient to cause heating of the carbon-containing material at a
rate of at least approximately 5,000 degrees C./sec, and need only be applied for
a fraction of a second to elevate the temperature of the carbon-containing material
at least approximately 1000 degrees C. Upon terminating the current, the carbon-containing
material is subjected to rapid-quenching (cooling). This may take the form of placing
one or more of the electrodes in contact with a heat sink, such as a large steel table.
The carbon-containing material may be rapidly-heated and rapidly-quenched (RHRQ) repeatedly
(e.g., in cycles), until a diamond material is fabricated from the carbon-containing
material. The process is advantageously performed in an environment of a "shielding"
(inert or non-oxidizing) gas, such as Argon (At), Helium (He), or Nitrogen (N2). In
an embodiment of the invention, the carbon-containing material is polystyrene (e.g.,
a film) or glassy carbon (e.g., film or powder). In another embodiment of the invention,
the carbon-containing material is a polymer, fullerene, amorphous carbon, graphite,
or the like. One of the electrodes is preferably a substrate upon which it is desired
to form a diamond coating, and the substrate itself is used as one of the two electrodes.
[0049] In a twenty-ninth embodiment, which utilizes the process that is taught in U.S. Pat.
5,525,815, a continuous diamond structure deposited by chemical vapor deposition is
disclosed having at least two thermal conductivity diamond layers controlled by the
diamond growth rate where one thermal conductivity diamond layer is grown at a high
growth rate of at least one micron per hour for hot filament chemical vapor deposition
and at least 2-3 microns per hour for microwave plasma assisted chemical vapor deposition,
on a substrate such as molybdenum in a chemical vapor deposition chamber and at a
substrate temperature that promotes the high growth rate, and the other thermal conductivity
diamond layer is grown at a growth rate and substrate temperature lower than the high
growth rate diamond layer. High growth rate and low growth rate diamond layers can
be deposited in any sequence to obtain a continuous diamond structure that does not
show distinguishable, separate, crystalline columnar layers, having improved thermal
conductivity.
[0050] In a thirtieth embodiment, which utilizes the process that is taught in PCT Publication
WO 95/31584 (Corresponding to International Application No. PCT/US95/05941), energy,
such as from a UV excimer laser, an infrared Nd:YAG laser and an infrared CO
2 laser is directed through a nozzle at the surface of a substrate to mobilize and
vaporize a carbon constituent (e.g. carbide) within the substrate (e.g. steel). An
additional secondary source (e.g. a carbon-containing gas, such as CO
2) and an inert shielding gas (e.g. N
2) are also delivered through the nozzle. The vaporized constituent element is reacted
by the energy to alter its physical structure (e.g. from carbon to diamond) to that
of a composite material, which is diffused into the back of the substrate as a composite
material.
[0051] In a thirty-first embodiment, which utilizes the process that is taught in PCT Publication
WO 95/20253 (Corresponding to International Application No. PCT/US95/00782), laser
energy is directed at a substrate to mobilize, vaporize and react a constituent (primary)
element (e.g. carbon) contained within the substrate. so as to modify the composition
(e.g. crystalline structure) of the constituent element, and to diffuse the modified
constituent back into the substrate, as an adjunct to fabricating a coating (e.g.
diamond or diamond-like carbon) on the surface of the substrate. This creates a conversion
zone immediately beneath the substrate, which transitions metallurgically from the
composition of the underlying substrate to the composition of the coating being fabricated
on the surface of the substrate, which results in diffusion bonding of the coating
to the substrate. Additional (secondary) similar (e.g. carbon) or dissimilar elements
may be introduced in a reaction zone on and above the surface of the substrate to
augment the fabrication of and to determine the composition of the coating. The laser
energy is provided by a combination of an excimer laser, an Nd: YAG laser and a CO
2 laser, the output beams of which are preferably directed through a nozzle delivering
the secondary element to the reaction zone. The reaction zone is shielded by an inert
(non-reactive) shielding gas (e.g. N
2) delivered through the nozzle. A flat plasma is created by the lasers, constituent
element and secondary element on the surface of the substrate and the flat plasma
optionally extends around the edges of the substrate to fabricate a coating thereon.
Pre-treatment and coating fabrication can be preformed in conjunction with one another
(in-situ). Alternatively, a substrate can be pre-treated to characterize its surface
for subsequent coating. In either case, certain advantageous metallurgical changes
are induced in the substrate due to the pre-treatment. The processes (pre-treatment
and coating fabrication) are suitably performed in ambient, without preheating the
substrate and without a vacuum. The lasers are directed at any suitable angle (including
coaxial) relative to the substrate and/or the plasma.
[0052] It is to be understood, however, that even though numerous characteristics and advantages
of the present invention have been set forth in the foregoing description, together
with details of the structure and function of the invention, the disclosure is illustrative
only, and changes may be made in detail, especially in matters of shape, size and
arrangement of parts within the principles of the invention to the full extent indicated
by the broad general meaning of the terms in which the appended claims are expressed.
1. A mold wall assembly (20) for use in a continuous casting machine, comprising:
an inner portion (29) that is constructed and arranged to conduct heat away from a
mold liner (30) during operation; and
an outer surface (44) that forms a casting surface (28) of the mold, said outer surface
(44) comprising a material that is selected from the group consisting of diamond and
cubic boron nitride;
characterized in that
the mold wall assembly (20) further includes optical monitoring means (48, 50)
for optically monitoring a property of the continuous casting process through said
material (44), and comprises an optical fiber (48) that is optically coupled to said
material (44) at a side thereof that is opposite the casting surface (28) of the mold.
2. A mold wall assembly (20) according to claim 1, wherein said optical monitoring means
(48, 50) comprises spectral measurement means for measuring the spectral characteristics
of light that is transmitted through said material (44), and means for analysing the
spectral characteristics of light that is measured by said spectral measurement means.
3. A mold wall assembly (20) according to claim 2, wherein said optical monitoring means
(48, 50) further comprises means for modifying at least one performance variable of
the continuous casting process in response to the analysis that is performed by said
means for analysing the spectral characteristics of light that is measured by said
spectral measurement means.
4. A mold wall assembly (20) according to claim 2, wherein said means for analysing the
spectral characteristics of light that is measured by said spectral measurement means
comprises means for sensing the temperature of an outer surface of cast strand that
is positioned adjacent the mold wall assembly.
5. A mold wall assembly (20) according to claim 3, wherein said means for modifying at
least one performance variable of the continuous casting process in response to the
analysis that is performed by said means for analysing the spectral characteristics
of light that is measured by said spectral measurement means comprises means for adjusting
the withdrawal speed of a continuous casting machine.
6. A mold wall assembly (20) according to claim 3, wherein said means for modifying at
least one performance variable of the continuous casting process in response to the
analysis that is performed by said means for analysing the spectral characteristics
of light that is measured by said spectral measurement means comprises means for adjusting
the rate at which heat is transferred away from said inner portion.
7. A continuous casting machine (10) including a mold wall assembly (20) according to
claim 1, the machine having a plurality of sensors (50) optically monitoring said
property of the continuous casting process and providing information to a CPU (52)
which is in two-way communication with a main control system (54) of the continuous
casting machine (10) and with one or more sub-systems each controlling a performance
variable of the continuous casting process in response to data gathered from said
sensors, the performance variables being selected from the group consisting of:
(a) adjustment of the withdrawal speed of the continuous casting machine;
(b) adjustment of the taper of the mold;
(c) adjusting the rate of cooling by adjusting the volumetric flow of coolant through
one or more of the mold walls, and
(d) adjusting the rate of cooling by changing the composition of mold flux thereby
changing the heat conduction properties of the mold.
8. A method of making a strand of continuously cast material, comprising:
(a) introducing molten metal into a mold that includes a plurality of mold surfaces
(27), at least one of the mold surfaces (27) having an outer surface (44) comprising
a material that is selected from the group consisting of diamond and cubic boron nitride;
(b) cooling the molten metal by conducting heat away from the molten metal through
the outer surface; and
(c) moving the cast strand out of the mold;
characterized in that the method
further comprises optically monitoring a property of the continuous casting process
through said outer surface material (44) involving the use of an optical fiber (48)
that is optically coupled to said material (44) at a side thereof that is opposite
the casting surface of the mold (27).
9. A method according to claim 8, wherein optically monitoring a property of the continuous
casting process through said outer surface material (44) comprises measuring the spectral
characteristics of light that is transmitted through said material, and the method
includes analysing the spectral characteristics of light that is measured by said
spectral measurement means.
10. A method according to claim 9, further comprising modifying at least one performance
variable of the continuous casting process in response to the step of analysing the
spectral characteristics of light that is measured by said spectral measurement means.
11. A method according to claim 9, further wherein analysing the spectral characteristics
of light that is measured by said spectral measurement means includes sensing the
temperature of an outer surface of a cast strand that is positioned adjacent the mold.
12. A method according to claim 10, wherein modifying at least one performance variable
of the continuous casting process comprises adjusting the withdrawal speed of a continuous
casting machine.
13. A method according to claim 10, wherein modifying at least one performance variable
of the continuous casting process comprises adjusting the rate at which heat is transferred
away from said inner portion.
14. An assembly according to any of claims 1-6, wherein said outer surface comprises a
smooth surface of a film of said material that is applied to a metallic substrate.
15. An assembly according to claim 14, wherein said film comprises a conversion zone which
transitions metallurgically from the composition of the underlying substrate to the
composition of said material.
1. Formwandanordnung (20) für eine Stranggußmaschine mit:
einem Innenteil (29), der so aufgebaut und angeordnet ist, dass er im Einsatz Wärme
von einer Formauskleidung (30) ableiten kann, und
einer Außenfläche (44), die eine Gußfläche (28) der Form bildet und aus einem Material
besteht, das aus der aus Diamant und kubischem Bornitrid bestehenden Gruppe gewählt
ist;
dadurch gekennzeichnet, dass die Formwandanordnung (20) weiterhin optische Überwachungseinrichtungen (48, 50)
zur optischen Überwachung einer Eigenschaft des Stranggußprozesses durch das Material
(44) hindurch enthält und einen Lichtwellenleiter (48) aufweist, der mit dem Material
(44) auf einer Seite desselben, die der Gußfläche (28) der Form gegenüber liegt, optisch
gekoppelt ist.
2. Formwandanordnung (20) nach Anspruch 1, bei der die optische Überwachungseinrichtung
(48, 50) Spektralmesseinrichtungen zum Messen der spektralen Eigenschaften von durch
das Material (44) hindurch übertragenem Licht sowie Einrichtungen zur Analyse der
spektralen Eigenschaften von von der Spektralmesseinrichtung gemessenem Licht aufweist.
3. Formwandanordnung (20) nach Anspruch 2, deren optische Überwachungseinrichtung (48,
50) weiterhin Einrichtungen aufweist, mit denen mindestens eine Ausführungsvariable
des Stranggußprozesses in Reaktion auf die Analyse modifizierbar ist, die die Einrichtung
zur Analyse der spektralen Eigenschaften von von der Spektralmesseinrichtung gemessenem
Licht ausführt.
4. Formwandanordnung (20) nach Anspruch 2, bei der die Einrichtung zur Analyse der spektralen
Eigenschaften von von der Spektralmesseinrichtung gemessenem Licht Einrichtungen aufweist,
mittels deren die Temperatur einer Außenfläche des Gussstrangs erfassbar ist, die
angrenzend an die Formwandanordnung angeordnet ist.
5. Formwandanordnung (20) nach Anspruch 3, bei der die Einrichtung zum Modifizieren mindestens
einer Ausführungsvariablen des Stranggussprozesses in Reaktion auf die Analyse, die
die Einrichtung zum Analysieren der spektralen Eigenschaften von von der Spektralmesseinrichtung
gemessenem Licht ausführt, Einrichtungen aufweist, mit denen die Abzuggeschwindigkeit
einer Stranggussmaschine nachstellbar ist.
6. Formwandanordnung (20) nach Anspruch 3, bei der die Einrichtung zum Modifizieren mindestens
einer Ausführungsvariablen des Stranggussprozesses in Reaktion auf die Analyse, die
die Einrichtung zur Analyse der Spektraleigenschaft von von der Spektralmesseinrichtung
gemessenem Licht durchführt, Einrichtungen zum Nachstellen der Geschwindigkeit aufweist,
mit der Wärme vom Innenteil abgeführt wird.
7. Stranggussmaschine (10) mit einer Formwandanordnung (20) nach Anspruch 1, welche Maschine
eine Vielzahl von Sensoren (50)aufweist, die die genannte Eigenschaft des Stranggussprozesses
optisch überwacht und Informationen an eine CPU (52) liefert, die in zweiseitiger
Übertragungsverbindung mit einer Hauptsteuerung (54) der Stranggussmaschine (10) steht,
wobei ein oder mehr Subsysteme jeweils eine Ausführungsvariable des Stranggussprozesses
in Reaktion auf von den Sensoren gesammelten Daten steuern und die Ausführungsvariablen
gewählt sind aus der Gruppe, die besteht aus:
(a) Einstellen der Abzuggeschwindigkeit der Stranggussmaschine;
(b) Einstellen der Formschräge;
(c) Einstellen der Kühlgeschwindigkeit durch Einstellen der Volumenströmung eines
Kühlmittels durch eine oder mehr der Formwandungen; und
(d) Einstellen der Kühlgeschwindigkeit durch Ändern der Zusammensetzung des Flussmittels
und daraus resultierendes Ändern der Wärmeleiteigenschaften der Form.
8. Verfahren zum Herstellen eines Stranges aus stranggegossenem Material durch:
(a) Einführen von Metallschmelze in eine Form mit einer Vielzahl von Formflächen (27),
von denen mindestens eine eine Außenfläche (44) aus einem Material hat, das aus der
aus Diamant und kubischem Bornitrid bestehenden Gruppe gewählt ist;
(b) Kühlen der Schmelze durch Abführen von Wärme von derselben durch die Außenfläche
hindurch; und
(c) Herausführen des Gussstrangs aus der Form;
dadurch gekennzeichnet, dass man eine Eigenschaft des Stranggussprozesses durch das Außenflächenmaterial (44)
hindurch unter Verwendung eines Lichtwellenleiters (48) überwacht, der mit dem Material
(44) auf der der Gussfläche der Form (27) entgegengesetzten Seite desselben optisch
gekoppelt ist.
9. Verfahren nach Anspruch 8, bei dem man zur optischen Überwachung einer Eigenschaft
des Stranggussprozesses durch das Außenflächenmaterial (44) hindurch die spektralen
Eigenschaften von durch das Material hindurch übertragenem Licht misst und bei dem
man die spektralen Eigenschaften von mittels der Spektralmesseinrichtung gemessenem
Licht analysiert.
10. Verfahren nach Anspruch 9, bei dem man weiterhin mindestens eine Ausführungsvariable
des Stranggussprozesses in Reaktion auf die Analyse der spektralen Eigenschaften von
von der Spektralmesseinrichtung gemessenem Licht modifiziert.
11. Verfahren nach Anspruch 9, bei dem bei der Analyse der spektralen Eigenschaften von
von der Spektralmesseinrichtung gemessenem Licht auch die Temperatur einer Außenfläche
eines Gussstrangs erfasst, der angrenzend an die Form angeordnet ist.
12. Verfahren nach Anspruch 10, bei dem zum Modifizieren mindestens einer Ausführungsvariablen
des Stranggussprozesses die Abzuggeschwindigkeit einer Stranggussmaschine nachgestellt
wird.
13. Verfahren nach Anspruch 10, bei dem man zum Modifizieren mindestens einer Ausführungsvariablen
des Stranggussprozesses die Geschwindigkeit nachstellt, mit der Wärme von dem Innenteil
abgeführt wird.
14. Anordnung nach einem der Ansprüche 1-6, bei der die Außenfläche eine glatte Oberfläche
einer dünnen Schicht des auf ein Metallsubstrat aufgetragenen Materials ist.
15. Anordnung nach Anspruch 14, bei dem die dünne Schicht eine Umwandlungszone aufweist,
in der die Zusammensetzung des darunter liegenden Substrats metallurgisch in die Zusammensetzung
des genannten Materials übergeht.
1. Un ensemble de paroi de moule (20) destiné à être utilisé dans une machine de moulage
continu, comprenant :
une partie intérieure (29) qui est construite et agencée pour conduire la chaleur
à distance d'un revêtement du moule (30) pendant le fonctionnement ; et
une surface extérieure (44) qui forme une surface de moulage (28) du moule, ladite
surface extérieure (44) comprenant un matériau qui est sélectionné à partir du groupe
constitué de diamant et de nitrure de bore cubique ;
caractérisé en ce que
l'ensemble de paroi de moule (20) inclut également un moyen de surveillance optique
(48, 50) pour surveiller optiquement une propriété du processus de moulage continu
à travers ledit matériau (44), et comprend une fibre optique (48) qui est couplé optiquement
audit matériau (44) sur un côté de ce dernier qui est opposé à la surface de moulage
(28) du moule.
2. Ensemble de paroi de moule (20) selon la revendication 1, dans lequel ledit moyen
de surveillance optique (48, 50) comprend un moyen de mesure spectrale pour mesurer
les caractéristiques spectrales de la lumière qui est transmise à travers ledit matériau
(44) et un moyen servant à analyser les caractéristiques spectrales de la lumière
qui sont mesurées par ledit moyen de mesure spectrale.
3. Ensemble de paroi de moule (20) selon la revendication 2, dans lequel ledit moyen
de surveillance optique (48, 50) comprend également un moyen servant à modifier au
moins une variable de performance du processus de moulage continu en réponse à l'analyse
réalisée par ledit moyen servant à analyser les caractéristiques spectrales de la
lumière qui sont mesurées par ledit moyen de mesure spectrale.
4. Ensemble de paroi de moule (20) selon la revendication 2, dans lequel ledit moyen
servant à analyser les caractéristiques spectrales de la lumière qui sont mesurées
par ledit moyen de mesure spectrale comprend un moyen servant à détecter la température
d'une surface extérieure de fil de moulage qui est située à côté de l'ensemble de
paroi de moule.
5. Ensemble de paroi de moule (20) selon la revendication 3, dans lequel ledit moyen
servant à modifier au moins une variable de performance du processus de moulage continu
en réponse à l'analyse réalisée par ledit moyen servant à analyser les caractéristiques
spectrales de la lumière qui sont mesurées par ledit moyen de mesure spectrale comprend
un moyen servant à ajuster la vitesse de retrait d'une machine de moulage continu.
6. Ensemble de paroi de moule (20) selon la revendication 3, dans lequel ledit moyen
servant à modifier au moins une variable de performance du processus de moulage continu
en réponse à l'analyse réalisée par ledit moyen servant à analyser les caractéristiques
spectrales de la lumière qui sont mesurées par ledit moyen de mesure spectrale comprend
un moyen servant à ajuster la vitesse à laquelle la chaleur est transférée à distance
de la partie intérieure.
7. Machine de moulage continu (10) incluant un ensemble de paroi de moule (20) selon
la revendication 1, la machine ayant une pluralité de capteurs (50) surveillant optiquement
ladite propriété du processus de moulage continu et fournissant des informations à
une unité centrale (52) qui est en communication à deux sens avec un système de contrôle
principal (54) de la machine de moulage continu (10) et avec un ou plusieurs sous-systèmes
contrôlant chacun une variable de performance du processus de moulage continu en réponse
à des données recueillies par lesdits capteurs, les variables de performance étant
sélectionnées à partir du groupe constitué des éléments suivants :
(a) ajustement de la vitesse de retrait de la machine de moulage continu ;
(b) ajustement de la conicité du moule;
(c) ajustement de la vitesse de refroidissement par ajustement du flux volumétrique
de liquide de refroidissement à travers une ou plusieurs parois du moule, et
(d) ajustement-de la vitesse de refroidissement par changement de la composition du
flux de moulage changeant ainsi les propriétés de conduction de la chaleur du moule.
8. Procédé de réalisation d'un fil de matériau moulé en continu, comprenant les étapes
consistant à :
(a) introduire du métal en fusion dans un moule qui inclut une pluralité de surfaces
de moulage (27), au moins l'une des surfaces de moulage (27) ayant une surface extérieure
(44) comprenant un matériau qui est sélectionné à partir du groupe constitué de diamant
et de nitrure de bore cubique ;
(b) refroidir le métal en fusion en conduisant la chaleur à distance du métal en fusion
à travers la surface extérieure ; et
(c) déplacer le fil de moulage hors du moule ;
caractérisé en ce que le procédé
comprend également la surveillance optique d'une propriété du processus de moulage
continu à travers le matériau de la surface extérieure (44) impliquant l'utilisation
d'une fibre optique (48) qui est couplée optiquement audit matériau (44) sur un côté
de ce dernier qui est opposé à la surface de moulage du moule (27).
9. Procédé selon la revendication 8, dans laquelle la surveillance optique d'une propriété
du processus de moulage continu à travers ledit matériau de surface extérieure (44)
comprend la mesure des caractéristiques spectrales de la lumière qui est transmise
à travers ledit matériau, et le procédé inclut l'analyse des caractéristiques spectrales
de la lumière qui sont mesurées par ledit moyen de mesure spectrale.
10. Procédé selon la revendication 9, comprenant également la modification d'au moins
une variable de performance du processus de moulage continu en réponse à l'étape d'analyse
des caractéristiques spectrales de la lumière qui sont mesurées par ledit moyen de
mesure spectrale.
11. Procédé selon la revendication 9, dans lequel l'analyse des caractéristiques spectrales
de la lumière qui sont mesurées par ledit moyen de mesure spectrale inclut également
la détection de la température d'une surface extérieure d'un fil de moulage qui est
situé à côté du moule.
12. Procédé selon la revendication 10, dans lequel la modification d'au moins une variable
de performance du processus de moulage continu comprend l'ajustement de la vitesse
de retrait d'une machine de moulage continu.
13. Procédé selon la revendication 10, dans lequel la modification d'au moins une variable
de performance du processus de moulage continu comprend l'ajustement de la vitesse
à laquelle la chaleur est transférée à distance de ladite partie intérieure.
14. Ensemble selon l'une quelconque des revendications 1-6, dans laquelle ladite surface
extérieure comprend une surface lisse d'un film dudit matériau qui est appliquée sur
un substrat métallique.
15. Ensemble selon la revendication 14, dans lequel ledit film comprend une zone de conversion
qui assure la transition métallurgique de la composition du substrat inférieur à la
composition dudit matériau.