JP2002522225A - Continuous cast molding system and method associated therewith - Google Patents

Abstract

An improved mold and process for continuous casting involves the use of a mold surface that is fabricated from a material, such as diamond, that is nonmetallic, an efficient conductor of heat and that is more degradation-resistant than the conventional materials and coatings that are used on mold surfaces. In one embodiment, the nonmetallic material is bonded to a conventional mold liner. In a second embodiment, the entire mold wall can be fabricated from the nonmetallic material. In another aspect of the invention, since materials such as diamond are transparent in the infrared range, the temperature of the outer shell of the casting can be monitored through the nonmetallic material without interfering with the casting process, and this information can be used to control one or more variables in the casting process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the technical field of metal formation and processing using a continuous casting process, and more precisely, the present invention relates to an improved mold surface for a continuous casting machine, and to the molding surface during operation of the machine. The present invention relates to controlling a casting process by accurately monitoring a casting temperature.

[0002]

[Prior Art and Related Art]

Metal production using continuous casting technology has increased since its large-scale introduction about 30 years ago, and today it accounts for a large proportion of steel and other products that are produced worldwide every year. As is well known, this continuous casting machine generally includes a mold having two generally parallel opposed wide walls and two substantially parallel opposed narrow walls, and the two pairs of wall Defines a quadrilateral casting path. Molten metal is continuously fed to the top of the casting passage and the mold is designed to cool the metal and form a skin before the billets (slabs) or strands exit the bottom of the casting passage. The casting surface of the mold is typically lined with copper or has a copper alloy surface layer so that heat can be exchanged quickly during the casting process to efficiently dissipate heat from the molten steel. It contains multiple passages for passing through. In some cases, the mold is cooled by spraying water directly onto the relatively cool side of the mold liner material. The strands are further cooled by water sprinkling until completely solidified away from the mold. It may then be processed by conventional techniques, such as rolling, into intermediate or final metal products, such as steel plates, sheets, coils, and the like.

[0003] The casting surface of the mold, also referred to as the "hot face" of the mold, is subject to prolonged exposure to hot molten steel and corrosive mold flows. Although copper is a very efficient heat conductor, it is relatively soft and rapidly wears and degrades. Under normal casting conditions,
The hot surface of the mold degrades relatively quickly due to wear, cracks, and steam, chemical attack, and the like. This effect is worse than in the case of high speed casting, which tends to occur at high temperatures, and the copper material begins to soften further. AG Industries, Inc., the assignee of the present invention, is the largest provider of maintenance and repair services for continuous casting machines in North America and has very detailed information on the deterioration and wear on the mold surfaces during casting. are doing.

To maximize the life of the mold surface, it is typical to precoat the copper mold surface with a friction and erosion resistant material such as nickel or chromium. Other techniques for protecting the mold wall have been proposed and / or generalized. For example, US Pat. No. 5,499,672 discloses a copper mold surface protection process performed by depositing a metal carbide protective material on the mold surface. Another protective coating technique uses a thermal spray process to deposit a Ni-Cr alloy on the copper mold surface. This process is based on the publication “Ni-Cr All” published in May 1989 by Nippon Steel and Mishima Kosan.
oy thermal spraying of the Narrow Face of Continuous Casting Mold. Although coating materials developed to date have reduced the rate and strength of mold wear to some extent, it is well known that the continuous casting industry must periodically remove, replace, or repair mold surfaces. is there. Removing the mold to do this could cost steelmakers $ 15,000 an hour.

[0005] Strands or billets have a very thin skin when initially formed in a mold.
This damage to the skin must be avoided at all costs. The reason for this is that this leads to a condition known as breakout, i.e. a condition in which the molten metal blows out of the shell below the mold surface. Serious breakouts extend to machine parts in the path of the molten metal, rendering those parts unusable and forcing replacement and repair. One of the factors that determines whether a breakout occurs is the thickness of the skin as the cast metal moves through the mold. Theoretically, the skin thickness could be measured during casting by monitoring the slab's infrared radiation, but in practice the entire slab is surrounded by the mold, making measurement impossible. Therefore, it is not feasible. Some systems model casting thickness by sampling temperature at selected locations within the mold liner, but these systems rely on the thickness of the copper material between the sensor and the casting surface. Is very inaccurate because it is not constant.

[0006] The continuous casting industry requires a mold surface that is more resistant to wear and degradation during casting than conventional mold surfaces. There is also a need for a continuous casting mold that can more accurately monitor cast metal moving within the mold to avoid breakouts and other unwanted conditions.

[0007]

Problems and Means to be Solved by the Invention

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a configuration of a mold surface which is superior in wear resistance and deterioration resistance during casting as compared with a conventional mold surface.

It is a further object of the present invention to provide a continuous casting mold that can more accurately monitor the casting metal moving in the mold to avoid breakouts and other unnecessary conditions.

To achieve these and other objects, according to the present invention, there is provided a casting mold wall assembly for use in a continuous casting machine, such that heat during operation is removed from the mold liner. A structured and disposed inner portion, and an outer surface that constitutes a casting surface of the mold, the outer surface comprising a degradable, non-metallic material having high thermal conductivity, whereby the mold A casting mold wall assembly is provided wherein the liner is configured to exhibit good resistance to degradation and heat transfer during operation of the continuous casting apparatus.

According to a different aspect of the invention, there is provided a method of producing a strand of a continuous cast material, comprising: (a) providing an outer coating of at least one mold surface comprising a degradable non-metallic material having high thermal conductivity. Introducing a molten metal to a mold having a plurality of mold surfaces having: (b) cooling the molten metal by removing heat from the molten metal through the outer coating; Moving the strands from the mold.

According to a third aspect of the present invention, there is provided a mold assembly for use in a continuous casting apparatus, the mold assembly having at least one mold surface and defining a casting space having an upper end opening and a lower end opening. Wherein at least one of said mold walls is formed of a non-metallic material having high thermal conductivity and high resistance to deterioration, thereby providing said good resistance to deterioration and heat transfer performance to the operation of a continuous casting apparatus. A mold assembly is provided that is configured to play therein.

According to a fourth aspect of the present invention, there is provided a method for producing a strand of a continuous casting material, comprising: introducing a molten metal into a mold having a plurality of mold surfaces; Cooling the molten metal by removing heat from the molten metal by conducting heat therethrough; and further cooling the molten metal located within the mold by radiant heat generated through the at least one mold surface. A method is provided.

According to a fifth aspect of the present invention, there is provided a mold assembly for use in a continuous casting apparatus, comprising a surface constituting a casting surface of the mold, the surface being at least partially in the infrared region. A mold assembly, characterized in that the mold cools the molten metal located in the mold by means of radiant heat conduction occurring through the surface.

[0014] These and other features and novel features that characterize the invention are pointed out in the claims hereof which are a part of this description. However, in order to understand the present invention, its effects and objects, it is necessary to refer to the description and drawings described in the following preferred embodiments.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Reference numbers are assigned to the corresponding structures throughout the figures. In particular, in FIG. 1, an improved mold wall assembly 12 for a continuous casting machine 10 includes a plurality of mold walls, including opposed elongated walls 14 and 16, and opposed wide walls 18 and 20. . Mold walls 14, 16, 18,
20 each have at least one mold surface, and these surfaces define a casting space 26 having openings at the top and bottom. The mold wall assembly 12 is conventionally designed so that the molten metal is continuously fed from the upper end of the casting space 26 and the skin is formed before the billet or strand exits from the lower part of the casting passage. The metal is cooled. As before, the pipes 22 and 24 for supplying the coolant are connected to the elongated mold walls 14 and
16 for supplying cooling water to the wide mold walls 18 and 20, respectively.

Reference is now made to FIG. FIG. 2 is a vertical cross-sectional view of one of the wide mold walls of FIG. 1, showing a liner assembly 27 having a mold surface 28, and a liner assembly 27.
A support assembly 32 for fixing the is shown in the mold wall 20. As seen in FIG. 2, the liner assembly 27 includes an inner portion 29 embedded in a copper liner 30 and an outer layer 44 of a non-degradable non-metallic material forming a mold surface 28, which will be described in more detail below. Is described in The support assembly 32 includes a coolant supply pipe 24, a coolant return pipe 42, a suction space 36, and a discharge space 38. Both the suction space 36 and the discharge space 38 are connected to a cooling channel 34 defined by a copper liner 30 included in the liner assembly 27. In operation, a coolant, typically water, as before, is drawn through the coolant supply pipe 24 into the suction space 36.
, From which it moves upward through the cooling copper channel 34 and flows out to the discharge space 38. Next, the coolant is returned to the circulation pump through the return pipe 42.

The layer 44 of non-metallic material, which is resistant to degradation, is an efficient heat conductor, high hardness, resistant to degradation, the high temperatures resulting from the casting process and the acidic conditions under which continuous casting machines typically operate. It is preferable to be made of a material that can withstand the above environment and is transparent in the infrared region for the reason described in detail below. There are two known materials that meet these requirements: diamond and crystalline boron nitride.

Diamond, an allotrope of carbon, is metastable at normal pressures and has a large activation energy barrier that prevents its return to black coal, a more stable allotrope at normal temperatures and pressures. Diamonds have been valued not only for their beauty and value as gems, but also for their numerous unique and valuable mechanical, electrical, optical and thermal properties. Diamond is the hardest of naturally occurring materials, has a low coefficient of friction and extreme resistance to chemical erosion, is optically transparent to most of the electromagnetic spectrum, and is particularly resistant to infrared radiation. It has high permeability and the highest thermal conductivity of all materials. Crystalline boron nitride (CBN) has properties similar to diamond in many respects.

One of the features of the present invention is illustrated in FIG. As can be seen from FIGS. 2 and 3, the passage 46 is formed by the copper liner plate 30 included in the liner assembly 27. An optical fiber 48 is located in the passage 46 and has a casting surface or layer 44.
On the side facing the mold surface 28, a layer 34 made of a non-metallic material having deterioration resistance and having permeability is provided.
Optically connected to Next, a sensor 50 is connected to the second end of the optical fiber 48, the other end. The purpose of sensor 50 is to monitor the characteristics of the continuous casting process by examining the spectral characteristics of the light passing through optical fiber 48. In the preferred embodiment, the sensor 50 is created and arranged to monitor the infrared properties of the transmitted light and the external temperature of the casting strand as it travels down the casting surface within the mold. By monitoring this temperature, the skin thickness of the cast metal, which is a useful indicator in many respects, can be determined. The indicators include the probability that the strand will break out after exiting the bottom of the mold, the optimal strand recovery rate from the casting machine, the optimal coolant circulation rate within the mold wall,
And uniformity of shell growth. Referring now to FIG.
That each of these sensors provide information to the CPU 52 acting as a local control system for the mold wall assembly 12, the central control of the continuous casting machine 10 Communicating bi-directionally with the system 54;
And this has been shown to communicate with other subsystems to modify various performance variables of the continuous casting process. Figure 4 shows four such subsystems
Although 56, 58, 60, 62 are illustrated, this number depends approximately on the number of performance variables that it is desired to control in response to the optical monitoring values performed by sensor 50. For example, one subsystem may adjust the recovery speed of the continuous casting machine, while another subsystem may adjust the taper of the mold. In the third and fourth subsystems, the flow rate of the coolant in one or more molds is adjusted to adjust the cooling rate of the mold of the coolant, and the composition of the mold flow is changed to change the heat conductivity of the mold. Properties can be changed.

In order to analyze the data acquired by the sensor 50, a general-purpose thermal image processing system can be used. One such image processing system is sold by Mikron Instruments (Auckland, NJ, USA) as an "Imaging Pyrometer". This system is partially disclosed in U.S. Pat. No. 4,687,344, the disclosure of which is incorporated herein as if fully set forth.

Reference is now made to FIG. A mold assembly 64 constructed in accordance with the second embodiment of the present invention includes a casting surface 66 and a body 68 made entirely of a non-metallic, degradable material of the type described in detail above. The cooling channel 70 is made of a material 68
A sensor 72, structurally similar to sensor 50 described above, is coupled to the rear of body 68. In this embodiment of the invention, the entire mold wall is made from diamond or CBN material. This embodiment is considered to have great potential since such mold walls are expected to significantly outperform any currently used mold walls. Made entirely of a material such as diamond, heat transfer from the strands during casting can be performed much more efficiently than metal mold walls and has a lower coefficient of friction than any metal mold wall And there is virtually no wear.

FIG. 6 shows another embodiment of the present invention. In this embodiment, as in the embodiment of FIG. 5, the mold liner 80 is all made of a degradable non-metallic material having high thermal conductivity, so that the mold liner is excellent for operation of a continuous casting machine. Shows wear and heat transfer characteristics. As in the embodiment of FIG. 5, the superior material is diamond or CBN, and the mold liner can be made by any of the manufacturing processes described below and by any effective process. A sensor 72, made similarly to the sensor 50 described above, is connected to the rear of the mold liner 80. In this embodiment, the mold liner 80 has no internal cooling passages, but the 86 side of the liner facing the cast metal 82
It is made as a “spray-type” mold that receives a spray of coolant from one or more nozzles 88. This type of mold liner has high thermal conductivity, which effectively cools the cast metal and helps to form a cast metal having a uniformly solidified shell 84. Also, the permeability of the mold in the infrared region allows a significant amount of heat to escape from the cast metal. This is a significant advantage over conventional continuous casting molds in which there is no heat transfer from the mold by radiation.

[0023] There are many methods of artificially using and mass-producing materials such as diamond and crystalline boron nitride as coatings, and the inventors use these known techniques within the scope of this invention. We recognize that we can do it. In addition, the inventor predicts that this technology is rapidly evolving and that as other more efficient technologies become available, they can create the required structures. The following U.S. Patent Publication and PCT International Publication disclose artificial coating and mass production techniques using materials such as diamond and crystalline boron nitride, and are considered exemplary for the purposes of this disclosure: . Each of the documents listed below is hereby incorporated by reference as if fully set forth herein.

[0024]

[Table 1] Most Preferred Processes for Applying the Non Metallic Wear Resistant Layer The first embodiment utilizes the process described in U.S. Pat.No.4,490,229, in which the substrate surface is exposed to an argon ion beam containing hydrocarbons. Alternatively, a diamond-like carbon coating can be deposited on the substrate surface. The ion beam current density during the initial deposition of the coating is low. Following this initial low current condition, the ion beam is increased to full power while a second argon ion beam is directed at the substrate surface. This second ion beam has a much higher energy level than the first beam containing carbohydrates. This additional energy to the system increases the mobility of atoms during solidification and helps to remove less constrained atoms and increase the percentage of diamond bonds.

The second embodiment utilizes the process described in US Pat. No. 4,504,519, which employs a mixing step in a deposition chamber using a radio frequency plasma deposited coating from an alkane such as n-butane. Amorphous, carbonaceous diamond-like coatings are typically made using a pair of parallel, spaced, and ultra-pure carbon electrodes. Most of the coatings according to the present invention are deposited using normal butane, and other alkanes such as methane, ethane, propane and hexane can be used in the process of the present invention to produce carbonaceous diamond-like coatings. it can. A deposition chamber made of stainless steel or the like generally contains a pair of pure, parallel, horizontally and vertically spaced carbon electrodes,
The substrate to be coated is associated with the lower electrode. These electrodes typically have a spacing of about 2-8 cm, with a spacing of about 2.5 cm being preferred. The deposition chamber is evacuated to an extreme pressure, typically 10 × 10 ^-7 Torr, and then filled with an alkane such as n-butane to 8 × 10 ^-4 Torr. Thereafter, the vacuum system is regulated by a valve to a pressure of about 25-100 mTorr. After stabilizing the pressure, a radio frequency current is applied to the pure carbon electrode pair, and the lower electrode (substrate target) is 0 V to about -100 V
A bias voltage of about -200 V to about -3500 V is applied to the higher electrode. Radio frequency plasma deposition is initiated, and at a rate of about 8-35 ° per minute, an amorphous, carbonaceous diamond-like coating is deposited on the substrate, forming a coating up to about 5 μm thick. The third embodiment utilizes a process described in U.S. Pat.No. 4,770,940, in which a gaseous hydrocarbon is decomposed to arrange adjacent carbon atoms in a single bond and form a tetrahedron. Thereby, a hard carbonaceous film is formed. Gaseous hydrocarbons are decomposed in a plasma maintained at radio frequency, and the decomposed substances are deposited on a cathode substrate. Optionally, fluorocarbon may be included in the deposition gas.

The fourth embodiment utilizes the process described in US Pat. No. 4,830,702, in which a hydrocarbon / hydrogen gas mixture is passed through a hard metal hollow cathode (where the hollow cathode is The temperature rises by self-heating). This gas mixture is separated by the mixing effect of heat and plasma. The plasma jet generated from the hollow cathode heats the substrate on the anode. The diamond coating is formed by strong electron irradiation.

The fifth embodiment utilizes the process described in US Pat. No. 4,910,041 in which one or two discharge electrodes are formed by a hot or quasi-hot plasma of a compound containing at least one carbon. The substrate is brought into contact with the plasma region to be formed to form a coating on the substrate. The electrodes include sheet-like electrodes having slits with straight portions and connected to a microwave power supply. In an alternative process, a plasma region is formed by moving a hot or quasi-hot plasma generated by an arc between the electrodes with a magnetic field. This step allows for energy efficient coating formation on the substrate surface.

The sixth embodiment utilizes the process described in US Pat. No. 4,939,763, in which a plasma current of 0.5-1.5 A and a temperature of 600-800 ° C. are obtained by deposition with DC plasma.
Thus, a synthetic diamond coating is formed using methane / hydrogen at a total pressure of 20-30 torr (volume ratio 0.8-1: 99.5-1).

A seventh embodiment utilizes the process described in US Pat. No. 4,948,629, which employs a high energy laser pulse and an aliphatic or aromatic carboxylic anhydride and a temperature of 400 ° C. Under CVD, a diamond coating is deposited on the substrate.

An eighth embodiment utilizes the process described in US Pat. No. 4,954,365, in which a substrate is immersed in a liquid containing carbon and hydrogen, and then the substrate is irradiated at least once with a laser pulse. By doing so, a diamond thin film is formed.

The ninth embodiment utilizes the process described in US Pat. No. 4,981,717, in which a diamond-like coating is deposited by depositing nuclides from a hydrocarbon gas precursor plasma. Plasma is generated by a laser pulse that is radiated onto the gas and absorbed by the initiator in the gas. The resulting explosion produces a plasma of ions, radicals, molecular fragments, and electrons, which are accelerated by the detonating pressure wave toward the substrate and deposit on the substrate.

A tenth embodiment utilizes the process described in US Pat. No. 4,987,007, in which a layer of material is deposited on a substrate by extracting ions from a laser ablator jet in a vacuum. It is formed. In a basic embodiment, this device
It has a vacuum chamber with a target material and a laser that irradiates the material to ablate it and ionize a portion of the ablative jet. The acceleration grid in the vacuum chamber is charged to extract ions from the jet and accelerate the ions toward the substrate to form a layer of material on the substrate. In this basic embodiment, a diamond-like carbon coating is deposited on a clean, nuclide-free silicon substrate at a rate of about 20 μm per hour. This diamond-like carbon coating has a uniform thickness of 1.5 mm with a smooth surface
It has exceptional quality, including a uniform refractive index in the range of ~ 2.5, a resistance in excess of 40 MΩ / cm, and a hard surface that can withstand physical wear. The enhanced embodiment has multiple targets in a vacuum chamber and a mechanism for selectively producing ions from each target. This allows layers of different or doped materials to be formed on the substrate. In addition, this enhanced embodiment also has a mechanism for forming patterns or circuits in each layer. One version incorporates a mask in the ion fluence or ion optics system, and the pattern of the mask can be enlarged and formed on a substrate. In another version, an ion beam is formed using ion optics, and the beam can be controlled by a deflector to form a desired pattern on a substrate.

An eleventh embodiment utilizes the process described in US Pat. No. 5,015,528, in which the deposition of a carbon gas source in the presence of atomic hydrogen on a substrate placed in a fluidized bed is performed. The synthetic diamond forming process involved is used. Diamond can also be overcoated by evaporation of non-diamond material.

The twelfth embodiment utilizes the process described in US Pat. No. 5,071,677 to increase the ability to supply (1) carbon, (2) hydrogen, (3) and halogen to a reactor on a substrate material. In this method, the diamond coating and particles are deposited on various substrates by flowing a gas or gas mixture. The reactive gas can be premixed with an inert gas to keep the overall volume of the gas mixture low in the specific volume of carbon and high in the ratio of hydrogen. Pretreatment of the reactive gas to a high energy state is not necessary, as is the case in most prior art steps of chemical vapor deposition of diamond. Since no pre-treatment is required, virtually any size, shape, or applicable to it. The reactive gas mixture is preferably passed through the reactor at an initial portion of from about 400 ° C to about 920 ° C, and more preferably at about 800 ° C to about 920 ° C. The substrate on which the diamond is to be formed is placed in an area in the reactor maintained at a lower temperature of the preferred diamond formation temperature range of about 250 ° C to about 750 ° C. The process is preferably performed at atmospheric pressure, but pressures before and after it are also possible. A considerable amount of pure diamond coating and particles are formed in just 8 hours. The purity of the diamond coating and particles has been verified by Raman spectroscopy and power X-ray diffraction techniques.

A thirteenth embodiment utilizes the process described in US Pat. No. 5,080,753, in which a thin film of single-crystal, crystalline boron nitride, disposed in parallel on a silicon substrate, is laser-coated. Formed using ablation technology.

The fourteenth embodiment utilizes the process described in US Pat. No. 5,082,359, and in this method of forming a polycrystalline coating such as diamond on a foreign substrate, a discrete nucleation site is defined. Preparation of the substrate takes place before the coating deposition. The substrate is prepared for film deposition by forming an irregular pattern on the substrate surface. The undulations (usually craters) are arranged in a predetermined pattern corresponding to the desired pattern at the location of the coating crystal. It is desirable that the craters are uniformly arranged at a predetermined size and a predetermined distance. Craters can be formed by a variety of techniques, including focused ion beam milling, laser evaporation or chemical or plasma etching using patterned photoresist. Once the substrate has been prepared, the coating can be deposited using a number of known techniques. Coatings produced in this way are characterized by a regular crystalline surface pattern, which can be arranged in virtually any arbitrary pattern.

A fifteenth embodiment utilizes the process described in US Pat. No. 5,096,740, in which an excimer laser is irradiated onto a target consisting of boron atoms and optionally nitrogen atoms, and is directed against the target. A high purity cubic boron nitride coating is formed on a substrate by a method that includes depositing cubic boron nitride on a disposed substrate.

A sixteenth embodiment utilizes the process described in US Pat. No. 5,154,945, in which an infrared laser is used to deposit a thin film of diamond on a substrate. During In certain embodiments, the coating deposition is carried out from a mixed gas of CH ₄ and H _2, mixed gas, which is sent to the chemical vapor deposition chamber, the laser is applied to the substrate surface to be coated, the Supplied to the substrate surface. In another embodiment, transmitted to the surface of pure carbon in the form of soot is coated, devoted to the surface laser beam directly in the environment to prevent become CO ₂ burned carbon.

The seventeenth embodiment utilizes the process described in US Pat. No. 5,221,411, and this method of forming a thin film of diamond on a non-diamond substrate is useful for grating-to-plane matching or lattice matching substrates. Including implanting carbon ions. The embedded portion of the substrate is then annealed to form a thin diamond coating on the non-diamond substrate. Also, the non-diamond lattice formed by this method
A thin diamond coating on a planar reference substrate is also disclosed. Preferred substrates are lattices and planes that match diamonds such as copper, the preferred implantation method is ion implantation, and the preferred annealing method is pulsed laser annealing.

The eighteenth embodiment utilizes the process described in US Pat. No. 5,221,501, using a substrate that is removed when a second layer is deposited on the diamond coating.
A method of manufacturing a transparent diamond plate is used. The second coating must have a refractive index that is approximately the same as diamond, and it is particularly preferred that it contains zinc selenide and titanium diocide. A diamond coating having two smooth surfaces by depositing two diamond coatings simultaneously on parallel opposing substrates until they contact and form a single coating or plate, and then removing at least a portion of the at least two substrates. Can be manufactured.

The nineteenth embodiment utilizes the process described in US Pat. No. 5,230,931 in which a diamond or I-carbon coating is formed on the surface of an object by the force of plasma-assisted chemical vapor deposition. Is done. The hardness of the coating can be enhanced by applying a bias voltage to the object during deposition.

The twentieth embodiment utilizes the process described in US Pat. No. 5,236,740, in which a substantial amount of carbide tungsten carbide substrate is prepared for coating with a diamond layer. The step of first removing a small amount of tungsten carbide on the surface of the substrate while leaving the cobalt binder intact is performed on the surface of the substrate to be coated. Murakami's reagent is currently preferred. Next, as a result of performing the step of removing tungsten carbide, the substrate is subjected to a step of removing any residue remaining on the surface. Solutions of sulfuric acid and hydrogen peroxide are presently preferred.
A diamond coated cemented tungsten carbide tool is formed using an unpolished substrate that can be prepared by etching as described above or etching with nitric acid before diamond coating. A fairly continuous deposition of a diamond coating can be achieved by reactive deposition, heat assisted (hot filament) CVD, plasma enhanced CVD, or other techniques.

The twenty-first embodiment utilizes the process described in US Pat. No. 5,243,170, and this method of coating a diamond coating on a substrate includes a plasma jet deposition method, wherein the deposited diamond coating is conventionally used. Have a predominantly hexagonal crystal structure different from the cubic crystal structure produced under the conditions described above, thereby further extending the advantages obtained by diamond coating of the tool in terms of hardness and smoothness of the coating surface. The only improvement is that only hydrogen is used as the plasma gas,
Control not to exceed 300 torr, maintain substrate surface temperature between 800 ° C and 1200 ° C, create a temperature gradient of at least 13,000 ° C / cm in the boundary layer of the substrate surface.

The twenty-second embodiment utilizes the process described in US Pat. No. 5,260,106, in which a first layer comprising a mixture of major components of a substrate and a sintering reinforcement for diamond is used. On the surface, then forming a second layer of the mixture of the above-described agent and diamond on the first layer, and finally forming a diamond coating on the second layer. Is firmly attached to the substrate.

The twenty-third embodiment utilizes the process described in US Pat. No. 5,264,071 in which the bonding strength between diamond and the substrate on which it is deposited by a chemical vapor deposition method is similar to that of a freestanding monolithic sheet. It is reduced to the extent that diamond can be peeled from the substrate. Adhesive strength can be reduced by polishing the substrate, removing corners from the substrate, slow cooling of the substrate after deposition, delayed cooling at intermediate temperatures, or the application or formation of an intermediate layer between diamond and the substrate. A separate sheet of diamond is envisioned for a particular use of the embodiment of FIG.

The twenty-fourth embodiment utilizes the process described in US Pat. No. 5,271,890, in which a carbon fine powder is continuously supplied to a substrate while a high power level laser beam is used. To induce sublimation of the carbon fine powder,
The sublimated carbon fine powder is rapidly cooled and deposited on the substrate, whereby a coating film of carbon allotrope is formed on the substrate.

The twenty-fifth embodiment utilizes the process described in US Pat. No. 5,273,731, which produces a highly transparent polycrystalline diamond coating having a thickness of 50 μm or more. The mixture of hydrogen and methane is conveyed to a hot filament reaction zone adjacent to a suitable substrate, such as a molybdenum substrate, to produce a non-cohered polycrystalline, highly transparent polycrystalline diamond coating.

The twenty-sixth embodiment utilizes the process described in US Pat. No. 5,273,788, in which a layer of hydrocarbon molecules is formed by Langmuir-Blodge.
tt) applied to the substrate by a technique, and the surface is illuminated with a laser to break down the molecular layers on the surface without affecting the substrate. After decomposition, the carbon atoms rearrange on the substrate surface, forming a DLC coating.

The twenty-seventh embodiment utilizes the process described in US Pat. No. 5,302,231, wherein a method of forming diamond on a diamond substrate by chemical vapor deposition involves first increasing the temperature of the diamond substrate to Cn Xm at elevated temperatures. Alternately contacting the gas, and then the CIZp-type gas. X and Z each form a single bond with carbon. In addition, X and Z are reactive to form ZX or derivatives. ZX bonds are stronger than CX bonds and stronger than CZ bonds. In the formula, n, m, l, and p are integers.

The twenty-eighth embodiment utilizes a process described in US Pat. No. 5,516,500, in which a diamond material is formed by sandwiching a carbon-containing material in a gap between two electrodes. By passing a high amperage between the two electrode plates, rapid heating of the carbon-containing material occurs. The current can cause heating of the carbon-containing material at a rate of at least about 5000 ° C / sec, and only takes a moment to raise the temperature of the carbon-containing material to at least about 1000 ° C. When the current is turned off, the carbon content is then quenched (cooled). This can be done by placing one or more electrodes in contact with a heat sink such as a large steel table. The carbon-containing material can be repeatedly heated and cooled (eg, periodically) until the carbon-containing material forms diamond. Argon (At), helium (He), or nitrogen
The process is advantageously performed in a "shield" (inert or non-oxidizing) gas environment such as (N2). In embodiments of the invention, the carbon-containing material is polystyrene (eg, a coating)
Or glassy carbon (eg, coating 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 on which the formation of a diamond coating is desired, and the substrate itself is used as one of the two electrodes.

The twenty-ninth embodiment utilizes the process described in US Pat. No. 5,525,815, in which a continuous diamond structure deposited by chemical vapor deposition has at least two thermal elements controlled by the rate of diamond formation. With a conductive diamond layer, one thermally conductive diamond has a high growth rate of at least 1 micron per hour for hot filaments and at least 2-3 micron per hour for microwave plasma assisted chemical vapor deposition. It is disclosed that a thermally conductive diamond layer is formed at a lower growth rate and substrate temperature than a high growth rate diamond layer formed thereon at a substrate temperature that promotes high growth rate in a chemical vapor deposition bath. . High-growth and low-growth diamond layers can be deposited in any order to obtain a continuous diamond layer with improved thermal conductivity that cannot be distinguished as a separate crystalline columnar layer.

The thirtieth embodiment utilizes a process described in PCT Publication WO95 / 31584 (corresponding to International Application No. PCT / US95 / 05941), and in this method, an ultraviolet excimer laser, infrared Nd: YAG Energy from a laser and an infrared CO ₂ laser is applied to the substrate surface to move and vaporize carbon components (eg, carbide) in the substrate (eg, steel) from the nozzle. An additional secondary source (eg, a carbon-containing gas such as CO ₂ ) and an inert shielding gas (eg, N ₂ ) are also provided from the nozzle. The vaporized component reacts with the energy and changes its physical structure into a composite structure that is diffused behind the substrate as a composite (eg, from carbon to diamond).

The thirty-first embodiment utilizes the process described in PCT Publication WO95 / 20253 (corresponding to International Application No. PCT / US95 / 00782), in which the laser energy is applied to the substrate ( A primary (e.g., carbon) element is applied to a substrate to transfer, vaporize, and react, altering the composition of the component (e.g., crystal structure), and forming a coating (e.g., diamond or diamond-like carbon) on the substrate surface. The components changed to be adjacent to () are dispersed in the substrate. This creates a transduction zone just below the substrate, resulting in a metallic change from the composition of the underlying substrate to the composition of the coating formed on the substrate surface, resulting in the dispersive bonding of the coating to the substrate. Additional (secondary) similar (eg, carbon) or dissimilar elements can be sent to the reaction area on the substrate surface to enhance the manufacture of the coating configuration or to determine the coating configuration. Laser energy is provided by a combination of an excimer laser, a Nd: YAG laser and a CO ₂ laser, the output beam of which preferably feeds a secondary element through a nozzle to the reaction zone. The reaction zone is shielded by an inert (non-reactive) shielding gas (eg, N ₂ ) supplied through a nozzle. A flat plasma is created on the substrate surface by a laser, components and secondary components, the flat plasma optionally forming a coating also around the edge of the substrate. Pretreatment and coating formation can be performed in conjunction with each other (as is). Alternatively, the substrate can be pretreated on its surface for subsequent coating to obtain the required characteristics.
In both cases, the pretreatment results in certain advantageous metallic changes in the substrate. Suitably, the steps (pre-treatment and coating formation) are carried out at ambient temperature, without preheating the substrate and without vacuum. The laser can be directed at any suitable angle (including coaxial) that is proportional to the substrate and / or plasma.

Although many features and advantages of the invention have been described above with details of the structure and function of the invention, the disclosure is illustrative only and should not be construed as limiting the details, in particular, the shape, size, and arrangement of parts. In face, it is to be understood that the full scope of the appended claims, which may be indicated by the broader general meaning of the conditions stated, may vary within the principles of the invention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a wall assembly of a mold for a continuous casting machine having a partially broken portion according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of one part of the mold wall assembly shown in FIG.

FIG. 3 is a schematic diagram illustrating preferred features of the assembly shown in FIGS. 1 and 2;

FIG. 4 is a schematic diagram showing an example of a preferred control system for the assembly shown in FIGS.

FIG. 5 is a cross-sectional view of a mold wall assembly according to a second embodiment of the present invention, which has a partially broken portion.

FIG. 6 is a cross-sectional view of a mold wall assembly according to a third embodiment of the present invention, which has a partially broken portion.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY , CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP , KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, UZ, VN, YU, ZW (72) Inventor Noble John El United States of America Pennsylvania 19086 Rose Valley Briake Drive 30 F term (reference) 4E004 AA10 AB02 MA01 MA05 PA05

Claims (32)

[Claims] 1. A casting mold wall assembly for use in a continuous casting machine, comprising: an inner portion configured and arranged to remove heat during operation from a mold liner; and a casting surface of the mold. An outer surface, the outer surface comprising a non-metallic material having high thermal conductivity, which is resistant to deterioration, so that the mold liner has good resistance to deterioration and heat conduction. A casting mold wall assembly configured to play therein. 2. The mold wall assembly of claim 1, wherein said non-metallic material having high thermal conductivity is selected from the group consisting of diamond and crystalline boron nitride. Mold wall assembly. 3. The mold wall assembly according to claim 1, wherein said non-metallic material having a high thermal conductivity and a deterioration-resistant material includes a carbon-containing material. 4. The mold wall assembly according to claim 1, wherein the non-metallic material having high thermal conductivity and having a high thermal conductivity includes a carbon allotrope. 5. The mold wall assembly according to claim 1, wherein said non-metallic material having high thermal conductivity is transparent in the infrared range. 6. The mold wall assembly according to claim 5, further comprising optical monitoring means for optically monitoring the condition of a continuous casting process through said material. 7. The mold wall assembly of claim 6, wherein said optical monitoring means comprises an optical fiber, said optical fiber being optically attached to a surface of said transparent material opposite said casting surface of said mold. An optical assembly, wherein the optical assembly is attached to the optical assembly. 8. The mold wall assembly according to claim 6, wherein said optical-optical monitoring means comprises a spectrum measuring means, wherein said spectrum measuring means measures a spectral characteristic of light transmitted through said transmission material. A mold wall assembly. 9. The mold wall assembly according to claim 6, wherein said optical monitoring means comprises means for analyzing a spectral characteristic of light measured by said spectrum measuring means. Wall assembly. 10. The mold wall assembly according to claim 9, wherein said optical monitoring means further comprises means for analyzing at least one performance variable of a continuous casting process with a spectral characteristic measured by said spectrum measuring means. Characterized in that it has means for changing according to the results of the analysis performed by the mold wall assembly. 11. The mold wall assembly according to claim 9, wherein the means for analyzing the spectral properties of the light measured by the spectrum measuring means comprises a temperature of an outer surface of a casting strand adjacent the mold wall assembly. A mold wall assembly comprising means for detecting 12. The mold wall assembly of claim 10, wherein at least one of the continuous casting performance variables is responsive to an analysis performed by the analyzing means of the spectral characteristics of the light measured by the spectral measuring means. Means for adjusting the rate of reduction in the speed of the continuous casting apparatus. A mold wall assembly. 13. The mold wall assembly of claim 10, wherein at least one of the performance variables of the continuous casting is responsive to an analysis performed by the analyzing means of the spectral properties of the light measured by the spectral measuring means. Means for adjusting the rate at which heat is transmitted from said inner portion. 14. A method for producing a strand of a continuous cast material, comprising: (a) at least one mold surface having a plurality of mold surfaces having an outer coating of a degradable non-metallic material having high thermal conductivity. Introducing a molten metal to a mold; (b) cooling the molten metal by removing heat from the molten metal through the outer coating; and (c) moving the strand from the mold. A method comprising: and 15. The method of claim 14, wherein in step (a), the high thermal conductivity, non-deteriorating non-metallic material is selected from the group consisting of diamond and crystalline boron nitride. A method performed under conditions. 16. The method according to claim 14, wherein the step (a) is performed under a condition that the high thermal conductivity non-deteriorating nonmetallic material includes a carbon-containing material. how to. 17. The method of claim 14, wherein step (a) is performed under conditions where the high thermal conductivity, non-degradable non-metallic material comprises a carbon allotrope. A method comprising: 18. The method of claim 14, wherein step (a) is performed under conditions wherein the high thermal conductivity degradable non-metallic material is transparent in the infrared range. The method characterized in that: 19. The method according to claim 18, further comprising an optical monitoring step for optically monitoring a condition of a continuous casting process through the material. 20. The method of claim 19, wherein the step of optically monitoring the status of the continuous casting process through a layer of quartz transparent diamond member comprises: opposing a casting surface of the mold of the transparent material. The use of an optical fiber optically attached to the surface. 21. The method according to claim 19, wherein the optical-optical monitoring step includes a spectrum measurement step, and the spectrum measurement step measures a spectral characteristic of light transmitted through the transmission material. A method comprising: 22. The method according to claim 21, wherein said optical monitoring step comprises a step of analyzing a spectral characteristic of the light measured by said spectrum measuring step. 23. The method according to claim 22, further comprising: at least one performance variable of the continuous casting step being a result of the analysis performed by the step for analyzing the spectral properties measured by the spectrum measuring step. A method according to claim 1, wherein the method includes a step of changing in response. 24. The method of claim 22, wherein analyzing the spectral characteristics of the light measured by the spectral measuring step comprises detecting a temperature of an outer surface of a casting strand adjacent the mold wall assembly. A method comprising the steps of: 25. The method of claim 23, wherein at least one of the continuous casting performance variables is changed in response to an analysis performed by an analysis of the spectral properties of the light measured by the spectrum measurement. Performing the step of adjusting the rate of reduction of the speed of the continuous casting apparatus. 26. The method of claim 23, wherein at least one of the performance variables of the continuous casting is responsive to an analysis performed by an analysis of the spectral properties of the light measured by the spectrum measurement.
The step of modifying one comprises means for adjusting the rate at which heat is transmitted from the inner portion. 27. A mold assembly for use in a continuous casting apparatus, comprising: a plurality of mold walls each having at least one mold surface and defining a casting space having an upper end opening and a lower end opening; The two mold walls are formed of a degradable non-metallic material having high thermal conductivity, thereby being configured to exhibit the good degradation resistance and heat transfer performance during operation of a continuous casting apparatus. A mold assembly, characterized in that: 28. A method of producing a strand of continuous casting material, comprising: (a) introducing molten metal into a mold having a plurality of mold surfaces; and (b) heat passing through the mold surface. Cooling the molten metal by removing heat from the molten metal by conduction; and (c) further cooling the molten metal located within the mold by radiant heat generated through the at least one mold surface. A method comprising: 29. The method of claim 28, wherein the at least one mold surface comprises a material that is substantially transparent in the infrared range. 30. The method of claim 29, wherein said material is selected from the group consisting of diamond and crystalline boron nitride. 31. A mold assembly for use in a continuous casting machine, the mold assembly having a surface comprising a casting surface of the mold, the surface being at least partially transparent to radiation in the infrared region. A mold assembly wherein the mold cools the molten metal located within the mold by means of radiant heat conduction occurring through the surface. 32. The mold assembly of claim 31, wherein said material is selected from the group consisting of diamond and crystalline boron nitride.