ES2288856T3 - PROCEDURE AND APPLIANCE TO SUPPLY METALLURGICALLY IMPROVED FUSED METAL. - Google Patents

Abstract

A method and an apparatus for enhanced metallurgical processing of molten metal includes an enclosable ladle chamber (23) for reducing the escape of heat during transport of the ladle from a manufacturing vessel such as a furnace (13) to an intermediate processing (15) or refining station or during processing or transport to a receptacle vessel such as a tundish (17). The method comprises introducing a refractory body into the ladle chamber (23), the body having an adjusted specific gravity having a reduced steel ballast to refractory material ratio that is less than required for a specific gravity required to buoyantly support the body in the molten metal. Preferably, the ratio provides a specific gravity greater than the specific gravity required to buoyantly support the body entirely in the slag layer. The method includes enclosing the ladle (22) for example, with a lid (90) and maintaining said refractory body in said ladle until substantially termination of the discharge of the molten metal from the vessel. Preferably, the method also includes intermediate refining such as introducing a balancing composition to the ladle before enclosing. The ratio of steel ballast and refractory material used to achieve the preferred specific gravity may also be adjusted in conjunction with other temperature-resistant or corrosion-resistant changes to the refractory body. For example, high temperature alumina may be used as a refractory material in a higher degree than in previously known bodies, a high temperature cement may be used to join the refractory material and ballast components, and a non-wetting agent made of carbonaceous or siliceous material may reduce deterioration of the body during the extended period of steel and slag contact in the ladle.

Description

Procedure and apparatus for supplying metal metallurgically improved cast.

Field of the Invention

The present invention relates to a procedure for enhanced metallurgical processing of cast metal compositions during transfer and supply of molten metal, and specifically to a process to improve metal casting procedures.

Prior art

In traditional alloy production metallic, the ingredients to prepare a composition Default metal are introduced into an oven, such as an oven basic oxygen or an electric arc furnace, in which constituents are liquefied and mixed to form a wash of molten metal. A layer of slag is carried that includes impurities and catalysts to the top of the molten metal layer. TO the molten metal is then discharged to a pouring spoon for transport to an intermediate or other processing post production facility, such as cord or sheet processing. In the production facility, the metal is discharged from the Pouring spoon to a bowl like a trough. While in the processing stations can provide heat sources to maintain a liquid mixture once the laundry has reached the processing destination, a substantial amount of heat is I was losing in the known open up spoons previously.

In order to address issues about energy conservation, it has been found useful to close the pouring spoons during transport of molten metal from the ovens to the processing equipment and during processing. By On the other hand, another recent innovation has been to strengthen the metallurgical composition of the laundry adding metallurgical improvements to the slag layer or molten metal while maintaining or Adjust the thermal energy in the pouring spoon. Unfortunately, although closing the chamber of the pouring spoon allows metallurgical improvement even during transport of molten metal from the oven to a processing or installation post production, the prolonged period of the conditions of Processing, which includes heat and inaccessibility, does not allow successfully employ in these known technical vessels formerly of laundry control.

For example, previously known techniques to control the discharge from the container in which it is placed a refractory cap and lowered over the nozzle by mechanical arms, as in a static oven, they cannot be used with containers closed. On the other hand, known refractory bodies previously as taught in US Pat. nº 4,601,415 for Koffron cannot be placed in a container closed when the level of molten metal in the container approaches at the critical level at which a vortex forms in the nozzle of discharge. Moreover, the previous refractory bodies formed with a specific weight designed exclusively so that lean floatingly on the fade can deteriorate quickly in prolonged exposure to spoon conditions of laundry and may not complete its intended function in contact Prolonged with molten metal and interface layer human waste.

Additional examples of such are described. refractory bodies for discharge control from containers metal casting in documents US-4854550, JP-540042305. These documents include caps of wash to automatically close and block a hole discharge of the laundry container. These wash plugs they comprise spheres that have a metal core coated with a refractory and arranged so that they have densities such that casting plugs are lighter than molten metal but more Heavy than scum. DE-4025605 unveils an additional similar ball used as a pouring plug, and that  is thrown into the laundry container at the right time to Close the discharge opening. The document JP-63180350, on the contrary, reveals an inhibitor of vortices, as opposed to a pouring plug, comprising a tray-shaped heat resistant refractory body, for float on molten metal to prevent the development of a vortex free in molten metal.

According to the present invention a procedure to improve metal casting procedures as defined in the attached claims 1 to 8.

Description of the invention

An embodiment of the present invention addresses the above-mentioned disadvantages by providing a process for improving metal casting processes that allows extended processing of molten metal and improves the amount of improved quality metal that is discharged from a container after Enhanced Processing In general, the process of metallurgical improvement processes of metal casting is combined with an enhanced supply which involves closing the metal casting vessel with a cover, preferably after starting the intermediate refining, for example, by introducing a balancing composition to achieve an equilibrium object composition in the container. The method comprises the introduction of a vortex inhibitor that is specially constructed with a refractory body, and the maintenance of the metal casting, preferably with the balancing composition, and a refractory body in the container, until the discharge of molten metal ends . A prolonged period of maintenance of the refractory body is allowed by the specially constructed vortex inhibitor in which the body of refractory composition modeled to fit in a pouring spoon is formed from a mixture of a steel stabilizer, refractory material and a penetration inhibitor, and has an adjusted specific gravity, the adjusted specific gravity having a ratio between steel stabilizer and refractory material less than the proportion for a specific weight required for the body's floating support in the molten metal at the interface of slag and molten metal in the pouring spoon. For a preferred alignment on the interface, the proportion is also preferably greater than the proportion for a specific weight required to support the body completely in the slag layer. The penetration inhibitor comprises at least one among a particulate carbonaceous material, silica and silica-based glass, and increases the penetration resistance and resistance to deterioration of the body throughout the time spent in the
metal.

As a consequence, in the present invention the refractory body resists deterioration during prolonged exposure to molten metal, slag and retained heat. He refractory body has a substantially more robust structure that maintains the integrity of the body in a way that provides Vortex reduction in casting operations previously inhospitable for the previously known control technology of slag and performance improvement. In addition, the pouring spoon cover provides an improved transfer mechanism and a enhanced metallurgical production system that allow greater precision in alloy production, improved production or quantities of use of high quality metals and greater efficiency energy than known production systems previously.

Brief description of the drawings

Fig. 1 is a partial diagram view of a processing facility for metal production that includes a sectional representation of a container of transfer used in the system;

fig. 2 is an enlarged elevation view in cross section of the bottom of a pouring spoon with a gate valve nozzle configuration for discharge molten metal; Y

fig. 3 is an enlarged elevation view in cross section from the perspective of the line 3-3 of fig. 2.

Detailed description of the preferred embodiment

Referring to fig. 1, a system is shown of metal production 10 comprising an installation of formation 12, a transfer mechanism 14 and an installation of processing 16. Training facility 12 may include a basic oxygen furnace, an electric arc furnace or other alloy fusion facility, in which raw materials basic for metal production are introduced in an oven and heat to melt and intermingle raw materials to production of a particularly desired metal composition. Although the quality and composition of the particular metal formed in oven 13 is consistent with the original raw materials introduced into the oven, the impurities in each of the ingredients can cause variations between the composition of desired metal and metal requirements to be used in a processing facility 16. Processing facility 16 it can be a volume production facility, for example, a cords manufacturing facility that includes a trough which receives molten metal for supply as a cord, or a sheet metal or other molten metal modeling article that hardens for subsequent overheating, modeling, conformation or processing. However, the complexity, the size and functional differences between team 12 and 16 make it is necessary to use a transfer mechanism 14 whereby the metal molten is discharged from training facility 12 and it supplies to an intermediate processing post 15 or to the processing facility 16 or between the post and the installation.

The invention is also well adapted for systems 10 in which a processing post can be included intermediate 15, as a secondary refining facility, between the production facility 12 and processing facility 16. In general, the oven produces steel in a chemical range and temperature That steel is then poured into a spoon of wash and transported to a ladle spoon refining oven, a stirring station or a degassing station, each of which can be described as a processing post intermediate, useful in adjusting metal chemistry. Chemistry and the temperature is then adjusted in a more exact range and narrow based on the desired quality to be produced, which is usually indicated by customer orders. In consequently, when preferred, each liquefied metal (cast) unloaded from the oven can be basically in the same interval of chemistry. Then all chemical adjustments are made for the various qualities that will be produced in the oven of Pouring spoon refining. For example, addition of materials such as Ca, Mn, Al, MgO, Si and calcium carbide; bubble of argon through steel; and overheating it with electrodes or other reheating procedures to improve Content compliance with specifications. Preferably, the intermediate processing takes place before the introduction of a refractory body when the body is not limits in position on a discharge nozzle by means extrinsic

In general, the transfer mechanism 14 includes a travel element 18 to transfer a load of molten metal. In the preferred embodiment, the element of displacement 18 includes a dragged spoon 22 by a support arm 24 or other transmission element, and can also include a support arm 24 for a cover 90 for the pouring spoon 22. In general, the support arm 20 supplies the pouring spoon to the training facility 12 so that the open top 26 of the pouring spoon 22 receives the discharge of a nozzle or other discharge opening of an oven 13 at installation 12. Similarly, the pouring spoon includes a discharge nozzle 28 which allows the content to be downloaded in a trough or other receiving vessel at the installation of processing 16. Preferably, the nozzle 28 includes a valve of gate 30. Gate valve 30 is sensitive to a control 32

Control 32 may include a sensor in the nozzle to detect if the flow through the nozzle is strangle, that is, is reduced in volume by an inhibitor of vortices or other plug, to finish the discharge of metal from the pouring spoon, preferably before the floating slag on top of the molten metal mix with the layer of molten metal. However, when using the body of the inhibitor of vortices, the transition from metal to slag is almost instantaneous because the body has almost eliminated mixing of metal-slag by vortex removal. The Transition happens very quickly and is almost discreet. Download it must be terminated regularly when workers observe slag or by any automatic detection, although termination in response to the strangulation observation may not lead to the maximum performance. The strangulation effect, or the transition from metal to slag flow, can be observed by the workers or, otherwise, be detected automatically. In addition, the response of control 32 can be initiated manually or automatically in response to strangulation detection or scum content detection.

As best shown in fig. 2, the answer Flow termination can be manipulated by mechanisms hydraulic-mechanical sensitive to the detection of constriction. For example, a hydraulic cylinder 40 whose piston 42 is coupled with a guide piece 44 is engaged with a box Sliding 46. Sliding housing 46 includes a recess bearing a sliding plate 48 made of material refractory. The slide plate 48 slides adjacent to a bottom plate 50, also made of refractory material and transported in metal with brick reinforcement 52. Metal with brick reinforcement 52 includes four lateral supports for plate and an adjustment mechanism with a set screw 54 for adjust the position of the bottom plate 50 with respect to the nozzle inserts when mounting the metal with reinforcement of bricks in the pouring spoon, so that the opening of the bottom plate 56 is aligned with opening 58 in an insert of nozzle 60. A bottom plate holder 62 is mounted or welded in the coating the ladle and gears with the sliding plate housing 64 bolted to the bracket of the bottom plate 62.

The opening 66 in the slide plate 48 moves through the sliding box in response to operation of the hydraulic cylinder 40 in a well known manner. In addition, the slide case rests on a clamp 68 by means of a clamp arm 76 (fig. 3) to retain a nozzle of chimney 70 in a chimney nozzle box. The nozzle of chimney 70 also includes an opening 74 that can be aligned with the openings 66 of the slide plate 48, 56 in the plate bottom 50, and the nozzle opening 58 in the nozzle of the insert 60. The chimney nozzle box 72 slides and is rotated in position with bayonet closures in the slide box 46. A clamp arm 76 includes a centered jogger that is moves in response to a clamp lever 80 to maintain the chimney nozzle 70 in alignment with the nozzle of the insert 60 and the gate valve open by displacement of the plate sliding 48 with respect to the bottom plate 50. A spring helical 82 mounted in a position of lower thermal influence of the gate supports the facial load on the brick of slip 48.

The open top 26 of the spoon laundry is closed with a cover or cover 90 that can be made of a refractory material or a coating covered with material refractory. The cover 90 is transported and placed with one arm of support 24. The cover 90 can be placed or hinged in the container to confine the inner chamber 23 of the spoon casting between the closed nozzle 28 and the open top 26. Such covers have been previously known for use in retain heat inside chamber 23. Moreover, in sight of the heat retained in the ladle, could be realized Enhanced metallurgical adjustments in the spoon content of laundry during transport time. In particular, before the cover 90 is placed on the open top 26 of a pouring spoon 22, constituents of additional alloys and catalysts in chamber 23 so that The content can be refined. In particular, the composition of molten metal in chamber 23 can be kept inside a desired range of alloy or combination while the layer of slag continues to provide catalysts that eliminate impurities of molten metal and prevents the reintroduction of impurities in the content of molten metal.

Preferably, adjustments are not made. during transport time, but rather when the spoon of laundry is at intermediate processing station 15 or in the secondary refining installation. The pouring spoon is not free of intermediate processing post 15 or installation of secondary refining for transport to the installation of production until the chemistry and temperature of the steel have reached a narrow object range. Preferably, the body refractory is introduced into the ladle after it have made all the adjustments in the processing post Intermediate 15 or secondary refining facility. Preferably, intermediate processing occurs before cover 90 is placed on top and more preferably, before the introduction of the refractory body, either in the Refining installation, during transportation to the installation of production or production facility.

As a result of the closing of the part open top 26 and the nozzle 28 of the pouring spoon 22, the camera 23 is inaccessible to further improvements, such as the use of a vortex inhibitor to control the intermingling of the layer of slag with the molten metal layer when discharge is desired metal. On the other hand, upon reaching the destination vessel 17 of the processing facility 16 by the mechanism of displacement 24, the cover 90 may not open until the Cast metal casting has been completed substantially or completely. In some plants, the cover is removed from the pouring spoon when the pouring spoon is almost empty. This can be done when the discharge pouring spoon is almost empty, and it is carried The next pouring spoon fills the continuous smelter discovered.

As a consequence, the introduction of a Vortex inhibitor in a ladle to be covered represents a substantially different period of time during the which the refractory body is subjected to contact with the metal molten and slag layer than in known uses previously. As a consequence, unlike inhibitors of previously known vortices, specific gravity and refractory body refractory adjust to provide appropriate results in the casting stage, which occurs substantially after filling, and after a while Extended transport confined. Preferably, the laundry is Produces after intermediate processing. Although the stage of laundry can last between 35 and 180 minutes, the refractory body must provide appropriate results during the last part, for example, 10 minutes, of the stage of wash.

In one example, although they were normally used refractory bodies with specific weight ranges from 4.8 to 5.2 to maintain the separation between the slag layer and the layer of molten metal in ovens for a period of approximately two to ten minutes to inhibit the formation of a vortex at the level of critical height of molten metal in the oven until throttling or other termination point used to terminate the flow from the discharged nozzle, said bodies were ineffective in the environment of closed ladle. As a consequence, it they made several changes to contribute to the longevity of the Vortex inhibitors in a ladle spoon environment. In In particular, the alumina (Al 2 O 3) was changed at a range of  high temperature and increased in proportion to the remaining constituents from about 45% by weight to about 70% by weight. In addition, the constituents were mixed with cement to high temperature, such as 1% to 2% by weight of, for example, a calcium aluminate cement or a high equivalent cement resistance or low water content.

On the other hand, the ratio between steel stabilizer and refractory material was reduced to give a specific gravity, preferably about 3.7, but preferably within the range of substantially 2.7 to 4.5. In addition, a non-wetting agent was introduced, preferably in form of a carbonaceous particle material, in the mixture refractory to reduce the amount by which it would penetrate the body molten metal or slag and would damage it, erode it, corroded, decomposed or dissolved by slag or metal cast, during extended periods of contact with steel and human waste. However, silicates, borosilicates and other silicate-based glasses as inhibitors of penetration.

Normally, materials can be used more expensive refractories such as MgO, but can be avoided when they should Limit expenses. In any case, the refractory body includes a mixture of steel stabilizer and refractory material and has a specific weight adjusted from inhibitors of refractory bodies known previously. The setting can include changes due to the desired target chemical of the metal, by example, stainless steel fibers, carbide of silicon, magnesite refractory materials, materials chrome refractories, zircon refractory materials, materials zirconia refractories, tabular alumina refractory materials or refractory materials of malite. The setting can be determined also by volume density specifications and life expectancy in cast steel. Preferred intervals of steel stabilizer with a weight per cubic decimeter of 10.5-14.1 #, preferably in a range of 30% at 80% by weight, and from 30% to 80% by weight of refractory material of the types previously disclosed. A binder of high temperature cement, at least able to withstand 538 ° C (1,000ºF) but preferably capable of withstanding from 1,315ºC to 1,815ºC (2,400ºF to 3,330ºF) without substantial deterioration, preferably from 2% to 12% by weight.

The reduced ratio between stabilizer of steel and refractory material has a specific weight less than required to flotrate the body in molten metal in the slag layer interface in the pouring spoon, although preferably greater than that required to support by body flotation in the slag layer. As a consequence, the specific weight and refractoriness (ability to resist or survive in a liquid metal environment), the adjustments have given as a result refractory bodies that are still maintained in manageable way to perform the functions of inhibition of vortices and strangulation even after the end of a prolonged exposure in the confined environment of a pouring spoon that transfers molten metal from an oven to a receiving container The change in specific body weight it can also ensure that the body is not absorbed in the nozzle of Download too soon.

Although forms of embodiment of the invention, it is not intended that these forms of realization illustrate and describe all possible forms of invention. Rather, the words used in the specification they are descriptive and non-limiting words, and it is understood that they can several changes be made without departing from the scope of the invention as defined in the appended claims.

Claims (8)

1. A procedure improvement procedure of metal casting with a metal casting vessel (22) that contains molten metal and a discharge opening (28) in said container, comprising the procedure: formation of a vortex inhibitor from of a mixture of a steel stabilizer, refractory material and at least one among a particulate carbonaceous material, silica and silicate-based glass to increase the strength of said body for penetration by molten metal and slag in the bucket of laundry (22), wherein said body has a lower specific gravity than that required for support by floating the body in said molten metal and greater than that required for flotation support of said body in a slag layer on top of the metal molten; introduction of the vortex inhibitor in the metal casting container (22) that closes the container metal casting (22) with a cover (90); Y maintenance of said vortex inhibitor confined in the metal casting vessel (22) during a extended period of time until a download of said molten metal. 2. The procedure as described in the claim 1 and further comprising carrying out a intermediate processing (15) in the metal casting vessel (22). 3. The procedure as described in the claim 2 wherein said intermediate processing comprises refined in pouring spoon. 4. The procedure as described in the claim 3 wherein said refining step comprises the introduction of a balancing composition into the container of metal casting (22) before said closing stage. 5. The procedure as described in the claim 4 wherein said refining step comprises degassing 6. The procedure as described in a any one of claims 1 to 5 wherein the stabilizer steel comprises between 30 and 80% by weight of the inhibitor of Vortices 7. The procedure as described in a any one of claims 1 to 6 wherein said material refractory comprises alumina, and said vortex inhibitor It comprises 45 to 70% alumina by weight. 8. The procedure as described in a any one of claims 1 to 7 wherein said weight specific to the vortex inhibitor is in a range of 2.7 to 4,5.