JPS63500043A - Method for processing molten metal and equipment for its implementation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Methods of processing molten metal and means for its implementation Technical field The present invention relates to the field of metal melting in metallurgy and foundry, and more particularly to the field of melting metals in metallurgy and foundry. The present invention relates to a method for treating the genus and means for its implementation.

Background technology Today, the trend in the steel manufacturing industry is to expand the capacity of melting equipment and increase the output per equipment. As a result, steel is becoming more sophisticated and of higher quality for a variety of uses.

The implementation of molten metal refining and finishing processes in large steel melting facilities with high production volumes is Regardless of its performance characteristics, it is accompanied by difficulties in bending, a substantial increase in heating time, and technical and The advanced method of degassing, desulfurization, deoxidation, alloy addition, etc., which deteriorates the economic index, is the melting method. It is carried out off-site, i.e. in the equipment most suitable for the purpose.

Modern ex-furnace metal processing methods require vacuum, inert or active gases, and highly reactive desorption. Acid and modifier powders are used, and intense stirring and heating of the reaction phase is also required. . These various methods depend on the rate and completeness of the reaction and the extent to which harmful impurities are removed. It has a great advantage over the specificity of realizing these within the melting equipment. Ru.

Ex-furnace treatment of steel is carried out by checking metal quality (sulfur content, gas content, amount of non-metallic inclusions, temperature and composition uniformity). It is widely used in continuous casting processes, which have stricter requirements for uniformity.

Ex-furnace processing of steel solves copper manufacturing problems such as: In other words, hydrogen in steel Removal of metal to a level that avoids stress cracking (flake cracking), controlled deoxidation, the formation of nonmetallic inclusions of a predetermined composition in a metal; Precise alloying of defined amounts of elements with very narrow fluctuations, metal stacks in a ladle Uniform temperature and composition throughout the body, complete decarburization of pure metals and molten alloys, desulfurization ( (if means of heating and stirring the molten metal and slag are available). Ex-furnace refining The use of the method increases copper furnace production and allows the furnace to be emptied more quickly for the next melt. This reduces the amount of ferroalloy wear and prevents rolling due to chemical composition defects and surface defects. Product defects are reduced, the quality of the final product is improved, and the service life of the product is extended. , high economic effects can be obtained.

The selection of the furnace and the method for refining metal outside the furnace depends on the grade of steel to be melted and the requirements for the product metal. determined by the quality of the casting, the technical cycle time and the casting conditions.

In addition to equipping the electric furnace factory with repeating and circulation type vacuum degassing equipment, A ladle vacuum degassing device with heat and stirring or oxygen injection functions under vacuum is also installed. It is a prerequisite to be prepared. Such vacuum degassers typically have a capacity of 20 It is installed in an electric furnace factory where electric furnaces up to 0 tons are installed, and the highest grade bearing steel, Used to produce structural alloy steels and various ultra-low carbon corrosion-resistant steels. in the ladle If you heat the metal, it will need to be overheated (superheat, 5uperheat) in the furnace. This increases the durability of the lining and substantially increases the production capacity of steelmaking equipment. Add.

What should be considered in the layout of a new electric furnace factory is the metal and Using electric heating and stirring of the slag and slag, a neutral gas and powdered additives are used to The aim is to arrange the equipment so that complex smelting of steel can be carried out below.

Known techniques (one of the techniques is a method of heating molten metal during deoxidation under vacuum and its implementation) (U.S. Pat. No. 3,501,289, 1970, Class 7) 5-12).

In this known method, a vacuum is created above the molten metal surface for degassing, and the electrode and molten metal are The molten metal is heated by an alternating current arc applied between the More complete degassing To do this, check the temperature difference between the part of the molten metal that comes into direct contact with the arc and the other parts of the molten metal. Stirring of the molten metal is necessary due to the convective heat exchange that occurs.

Since combustion in an electric arc involves substantial heat loss by radiation, the molten metal of this known method The energy efficiency of heating is low. As such, the method requires a vacuum to perform. This is a substantial drawback. In addition, the above method also includes alloying element addition, decarburization Processing of metals such as deoxidation, desulphurization or dephosphorization with slag formation. It is technically difficult to do so.

This known method is carried out in a facility having a vacuum chamber containing a molten metal container inside.

Means for fixing the non-consumable electrodes are provided within the body of the vacuum chamber. This electrode Can move in planes and vertical planes.

Furthermore, there is also a means for applying voltage to the molten metal from an AC power source.

The means of heating the molten metal during vacuum degassing is complicated by the need to maintain a vacuum. be.

One known method is a molten metal refining method (FRG Patent No. 1,217,986). No., 1966, classification 18b).

, this known method uses oxidizing gas to reduce the amount of carbon in the molten metal. This oxidized molten metal is then oxidized using a plasma jet generated using an inert gas. Heat in a hot pot. At the same time, a triatomic gas is introduced into an inert gas as an active medium. .

Hydrogen is used as a diatomic gas for deoxidizing the molten metal. At that time, inert gas The amount of hydrogen introduced into the plasma is such that the plasma mainly consists of hydrogen. Deoxidation of molten metal Later, an inert gas, e.g. argon, is again used as plasma-forming gas. It will be done.

Substantial heat loss due to radiation due to the formation of plasma shared above the molten metal surface A loss occurs. Therefore, energy efficiency is low.

Using this known molten metal refining method, heat exchange and The process of material exchange is slow and the refining time is long, making it uneconomical. Moreover, molten metal Some parts of the process may be incomplete.

In this known method, (7)? at the metal-slag-plasma jet interface. 9t Processes such as desulfurization and dephosphorization that involve slag formation cannot be carried out because n is not effectively agitated. unable to do the right thing perfectly. Furthermore, stirring is performed only by convective heat exchange. temperature and composition is not uniform throughout the metal. It is practically impossible to carry out alloying additions to the molten metal by known methods.

Equipment for carrying out this known method consists of a ladle for molten metal and a cold plasma jet generator. and a plasma generator for molten metal. It is arranged and installed for reciprocating movement.

The ladle refractory liner is shorten the service life of the ring.

The closest prior art to the present invention is a method for refining molten metal using a direct current plasma jet. and means for its implementation (U.S. Pat. No. 3,547.622, 197 Year 0, classification 75-10).

In this known method, a cold plasma is generated by passing a plasma-forming gas through an arc. Generates a plasma jet and converts this low-temperature plasma jet into molten metal, that is, molten steel. The molten steel is delivered and heated, a vacuum is formed above the molten metal surface, and a direct current is passed through this vacuum. The molten metal is stirred by creating a DC magnetic field that works together with the magnetic flux of the arc. Do this.

Degassing of the molten metal can be achieved by processing the molten metal under vacuum, stirring with a low-temperature plasma jet, or and during heating.

Since the combustion of an electric arc involves substantial heat loss by radiation, this known method Heating energy efficiency is low. This method requires a vacuum, so it is practically There are difficulties in In addition, when this known method is carried out as described above, alloying element additions Processing of molten metal such as addition, deoxidation, and further desulfurization and dephosphorization with slag formation. is technically difficult.

This known molten metal processing method is difficult to effectively stir the molten metal and requires heat exchange. and the surface area of the high-temperature plasma-molten metal interface, where mass exchange takes place most effectively, is small. The small size requires substantial energy consumption.

This known method consists of two metal transport channels arranged one above the other in a vertical plane and interconnected by two metal transport channels. The process is carried out in a facility comprising two molten metal baths that are connected to each other. One of the baths has a vertical surface A low-temperature plasma placed above the molten metal surface and reciprocating within the molten metal. - A plasma generator for jet generation is provided.

The equipment is equipped with a DC power source to generate a cold plasma jet. Ru.

Plasma is used to simultaneously heat, stir, and degas molten metal under vacuum. ・The ionized gas column of the arc collides with the surface of the molten metal, generating a high amperage direct current. Flows through the plasma arc column into the molten metal bath. Directly in the direction of arc current flow A DC magnetic field passing through the bath at the corner acts in conjunction with the magnetic flux induced by the arc current to transform the molten metal. Move along the perimeter of the rectangle.

The equipment used for processing molten metal has two baths lined with refractory material. Moreover, it is complicated to implement because it requires creating a vacuum above the molten metal.

Because the plasma arc is high amperage and the molten metal circulates, the metal transport path is and poor durability of the refractory lining of the bath. In particular, in practice, processing of molten metal is Since the treated molten metal is drained and new molten metal is injected periodically, the bath is always This becomes even more technically complex due to the unsealing process.

Disclosure of invention The object of the present invention is to provide heat exchange and material exchange between a low temperature plasma jet and molten metal. Delivering a cold plasma jet into the molten metal to facilitate exchange and additives By supplying It promotes heat exchange and mass exchange between fillers, and also has a simple structure for molten metal processing. Molten metal processing methods and methods that improve the mechanical and practical properties of alloys by means of The goal is to provide the means to implement it.

The purpose is to create a cold plasma jet by passing a plasma forming agent through the arc. A method of processing molten metal that generates a jet of plasma and delivers a low-temperature plasma jet to the molten metal. In the process, the cold plasma jet is applied to the molten metal to agitate the molten metal. Delivered to the surface side of the molten metal inside the metal body at a speed of about 1500 m/s and the additives are previously introduced through the plasma jet. Achieved by metal processing methods.

Plasma and molten metal by delivering a low temperature plasma jet inside the molten metal can substantially facilitate heat and mass exchange between In this case, the melt The floating plasma-forming gas bubbles, which are hotter than the hot water, impart thermal energy to the molten metal. Therefore, the total thermal energy of the plasma jet is actually spent heating the molten metal. It will be done.

If the thermal energy of the plasma jet is high, the material between the plasma and the molten metal The reactive capacity of the plasma-forming gas to promote the exchange process is increased. Furthermore, the present invention The implementation of the method provides the advantage of using plasma technology most effectively.

In other words, a compound that has been heated or melted in a plasma arc to give it high reaction ability. Plasma technology is used to deliver the gold and slag-forming additives. simultaneous The plasma arc is an effective heat source, and the plasma arc is Immersion eliminates radiant heat loss and provides the highest thermal efficiency, making it virtually It becomes possible to start the process of molten metal processing at a significantly lower temperature.

When carrying out the method of the invention, it is desirable to use nitrogen-containing additives.

The use of nitrogen-containing additives, for example, Substituting some of these elements in corrosion-resistant and wear-resistant steels that contain tenite-forming elements It is most effective when alloyed for specific purposes.

In carrying out the disclosed method, particles having a size in the range of about 0.1 to about 1.0 mm are prepared in advance. It is desirable to use finely ground slag-forming additives. Occurred in the bath of steel manufacturing equipment. The rates of the various processes (slag formation, dephosphorization, desulfurization, etc.) substantially slower than the rate of heating of the genus.

Powdered slag-forming additives are activated in advance in a plasma arc and added to the molten metal body. When the surface layer of metal/slag is developed to the highest degree, processes such as dephosphorization and desulfurization occur. conditions are created for the highest speed.

When using slag-forming additives, the plasma generating agent has a volume of 0 to 100% of its own volume. Oxygen may suitably be included in an amount of vol.

The use of oxygen in the above amounts promotes the formation of a highly active iron-bearing limestone slag. Slag is formed in a molten metal body), and the dephosphorization process occurs during the floating of slag particles. Stir molten metal effectively.

The purpose of this is to provide a It consists of a plasma generator for generating low-temperature plasma jets located in In the means for carrying out the molten metal processing method, the plasma generator includes a nozzle. The nozzle has an end face facing the molten metal and a low temperature plasma jet. having an inlet substantially equal to an outlet of the plasma generator at the outlet; The length of the part of the nozzle immersed in the molten metal is about 0.1 to about the height of the column of molten metal. This is also achieved by the molten metal processing means of the present invention which is 0.8 times as large.

The presence of a nozzle on the end face of the plasma generator enables low-temperature plasma jet generation. molten metal and pre-activated additives below the surface of the molten metal. Conditions are obtained for introducing and further activating mass exchange processes. Low temperature plasma di The molten metal-slag-gas interface is A highly developed surface is created, so that heat and mass exchange is substantially and economics of additives such as slag-forming additives are achieved.

The plasma generating device may be mounted such that it is suitable for movement in a horizontal plane.

This allows the molten metal to be treated in its entirety, including its periphery; As a result, the temperature and composition of the molten metal can be leveled out rapidly. In particular, plasma generator It is necessary to move a large amount of molten metal (more than 5 tons) in a horizontal plane. This is because it is most advantageous when processing the genus.

It is desirable to use a torch-type plasma generator. This type of plasma generator Additives may be added to the molten metal when there is no need to substantially heat the molten metal itself. Most suitable for shipping inside. In this case, to apply a potential to the molten metal There is no need to use special electrodes.

Plasma generators with external plasma arcs substantially heat the molten metal High melting point additives that require relatively high temperature plasma sharing for melting It is convenient to use when using additives.

The nozzle can be equipped with a plate such as: i.e. this plate has a central hole coaxial with the internal hole of the nozzle, and a direction from the center to the periphery of the plate itself. It has an increasing number of vertical through passages.

This plate facilitates heat and mass exchange between the plasma and the molten metal. It is designed to extend the travel path of gas bubbles in the molten metal and extend the residence time. lengthen This breaks up gas bubbles more effectively. However, most of the gas bubbles Effective splitting is achieved by ensuring that the floating gas bubbles are split and then evenly distributed as they enter the passageway. The plate adds vertical passageways that allow the entire molten metal to float above the This will be achieved if you have the following.

In the inlet zone, the nozzle may be provided with holes for the introduction of additives. like this The large pores provide a desirable effect on the delivery of powdered additives into the molten metal.

Brief description of the drawing For a clearer understanding of the present invention, preferred embodiments are described below with reference to the accompanying drawings. This will be explained in more detail.

Figure 1 shows a vertical cross-sectional view of the ladle and a partial cross-sectional view of the plasma generator lifting and lowering rotating mechanism. Best mode for carrying out the schematic invention of the molten metal processing means of the present invention including The molten metal processing method disclosed herein involves passing a plasma generating agent through an arc. involves the generation of a low-temperature plasma jet.

The plasma generating agent is argon, nitrogen, oxygen, hydrogen, and/or a mixture thereof. selected from a set of objects.

Additionally, the disclosed method is intended to deliver a cold plasma jet to molten metal. do.

In the molten metal processing method, the arc output is maintained at a level of about 50kW to about 5.0cm. The amount of molten metal ranges from about 50 kW to about 25,000 kg. low temperature Lasma jet is delivered to the surface inside the molten metal body at a speed of 1500 m/s This causes the molten metal to be stirred. Introducing additives can be done by pre-purifying the additives. This is done by passing it through a lasma jet.

Additives include nitrogen-containing additives (e.g. pure nitrogen, nitrogen-argon mixtures) and and pre-ground slag-forming additives (e.g. (e.g., alloying element powders such as titanium and tungsten, lime, gravel, etc.) are used. .

When slag-forming additives are used, the plasma generating agent is It should contain oxygen in the range of 0.00vol.

Means for carrying out molten metal processing include generating a low temperature plasma jet 2. It comprises a plasma generator 1 (FIG. 1). Plasma generator N1 is vertically It is arranged to move back and forth within a special container 4 (for example a ladle or The molten metal 3 is placed above the surface of the molten metal 3 contained in the receiving tank. Plasma emission The raw equipment 1 is equipped with a nozzle 5, and the end face of the nozzle 5 faces the molten metal 3. At the location of the discharge of the warm plasma jet 2 there is substantially the outlet of the plasma generator 1. The length of the part of the nozzle 5 immersed in the molten metal 3 is the same as that of the molten metal 3. It is about 0.1 to about 0.8 times the height of the column of molten metal 3.

To perform reciprocating motion in a vertical plane of the plasma generator 1 equipped with the nozzle 5 The drive device used has a support plate 8 placed on a base 6 via a spherical support 7. In addition, the support 9 and the main bodies of the lower support 10 and the upper support 11 are fixed to the base 6. has been established. The lead screw 14 has a special lower thrust in the supports io, ii. It is fixed in a bearing 12 and a special upper thrust bearing 13. Turns to lead screw 14 The rotation is transmitted from the electric motor 15 via the transmission device J6. perform translational movement A nut 17 is secured to the lead screw 14.

In order to prevent the nut 17 from rotating together with the lead screw 14, a A slotted hole 9' holds a nut 17. Plasma generator equipped with nozzle 5 1 is fixed to a bracket 18 fixed to a napht 17.

The configuration of the means disclosed herein enables movement of the plasma generator 1 in a horizontal plane. Ru. For this purpose, the drive device is rotated about its own axis on the spherical support 7. It will be done.

This means can be achieved by using a torch-type plasma generator (not shown) or an external plasma arc. A plasma generator of the type shown in FIG.

When processing molten metal according to the first embodiment, the arc is a torch-shaped plasma. It is formed between the anode and cathode of the generator 1.

When using the plasma generator 1 with an external plasma arc, the arc is connected to the cathode. and the molten metal 3, and a direct current is applied to the molten metal 3 via a special electrode 20. The anode of source 19 is connected. Even if the electrode 20 is immersed on the bath surface side in the molten metal, Alternatively, it may be placed on the bottom or side wall of the molten metal processing vessel.

In the outlet zone, the nozzle 5 has a central hole 2 coaxial with its internal hole (FIG. 1). 2 (FIG. 2).

Plate 2J may be made as a solid body or in the process of Plate 21 is completely submerged in molten metal 3. By doing this As a result, the path of movement of the gas bubbles 2' floating in the molten metal 3 is extended, and the gas bubbles 2' Since the plasma 2 is divided when it passes through the vertical passage 23 of the plate 21, the plasma 2 and the inner diameter of the container 4 in which the heat exchange and material exchange 3 process between the molten metal 3 and the molten metal 3 take place. It is about 1/3 to about 1/2 of that. According to this plate size, the processing process can be carried out and processed. maximum effectiveness is ensured. The vertical passage 23 of the plate 21 has a round cross section. Or it can be square.

The optimum inner dimension of the through passage 23 is 8 to 10 mm. Internal dimensions (hole diameter or If the square side) exceeds 10 mm, some of the through passages on one side of the nozzle 5 may be tends to pass through, causing the through-way to function unevenly. Penetration path 23 If the dimension of An ugly situation arises.

The gas plasma jet passing through the passage 23 is divided into small pieces floats above the plate 21 in the form of gas bubbles 2', thereby causing highly developed gas A metal/metal interface is provided. Ensure that all of the molten metal is processed above plate 21. Also, in order to In order to avoid a situation where the They are arranged uniformly and the quantity (density, intensity) of the through passages 23 is increase from the center to the periphery.

In the inlet zone, the nozzle 5 has holes 24 (FIG. 1) for the introduction of additives. have This allows the powdered additive to pass through the plasma jet 2 to the molten metal. It can be introduced into the main body of 3.

The means for treating the molten metal in the ladle operates as follows.

High manganese steel is used as the processing target. Heating takes place in an induction furnace. Lifting and turning mechanism The molten metal is poured from the induction furnace into the ladle.

Water for the cooler of the plasma generator 1 is delivered to a water supply 25 (FIG. 1).

At the same time, delivery of plasma-forming gas is started through the connection terminal 26. Power switch Turn on the switch and apply voltage to the plasma generator to generate an arc.

The plasma generator equipped with the nozzle 5 is lowered and the nozzle 5 is immersed in the molten metal. do. As a result, a lining zone is formed in which processing of the molten metal takes place.

In order that the invention may be more fully understood, specific examples of embodiments of the invention are illustrated in the drawings below. I will explain while referring to it.

Example 1 The composition is 0.36% carbon, 0.29% silicon, and 0.61% manganese in weight percent. Steel was produced in an induction furnace. Next, pour this molten metal into a ladle with a capacity of 160 kg, The plasma generator was moved to the ladle using an elevating and rotating mechanism. plasma generator The equipment was started under the following operating conditions. i.e. arc current 350A, plasma formation Gas (argon) consumption was 3.2 g/s. Next, the nozzle of the plasma generator The slurry was immersed into the molten metal to a depth of 601 cm and the treatment was carried out for 10 minutes. after that Molten metal was cast. At the same time, metal samples were taken for mechanical property testing.

The obtained test piece was normalized. The mechanical properties of this treated steel are as follows: be. That is, σs 560MPa, 623%, '%28%, KCV (impact Strength') 460 kJ/bo, where σ is the tensile strength and δ is the elongation.

For comparison, the mechanical properties of the same steel without treatment are ('B 480 MPa , δ16%, ≠21%, KCV (impact strength) 355 kJ/m. plasma As a result of examining the cast metal after treatment, it was found that steel of the same composition without plasma treatment In comparison, it was found that the amount of non-metallic impurities was reduced by 30-50%. Moreover, Non-metallic impurities are crushed, have a precise surface, and are uniformly distributed throughout the metal .

It has been established that the amount of gas in metals treated by plasma is substantially reduced. It has been certified. For example, the oxygen content decreases from 0.0035% to 0.0024% Ta. Examination of the steel after plasma treatment revealed a low hydrogen content of 0.00065%. amount, which is substantially lower than the starting material with a hydrogen content of 0.00085%. stomach.

These improving factors substantially enhance the mechanical and practical properties of the cast product.

Example 2 The treatment was carried out on wear-resistant steel produced in an induction furnace. The composition of this copper is 1% carbon by weight. ．． 10%, manganese 12.20%, silicon 0.83%, titanium 0.09%, sulfur 0.037%, 0.074% phosphorus, and 0.0072% nitrogen. Then pour the molten metal 160 kg of plasma was injected into a ladle and immersed in the molten metal in the ladle. Nitrogen from the arc was alloyed through a nozzle.

The plasma generator was started under the following operating conditions. That is, arc current 300 A. The consumption amount of plasma generating gas (nitrogen) is 4.5 g/s. Melt the bottom end of the nozzle. It was immersed in the molten metal to a depth of 50 to 60 mm. Depending on this type of processing Metals and gases can be effectively agitated, allowing for heat exchange and mass exchange. Provides a highly developed surface for The chemical composition of the metal after 12 minutes of blowing is , carbon 1.07%, manganese 12.0%, silicon 0.75%, sulfur 0.032% , 0.068% phosphorus, and 0.065% nitrogen. The mechanical properties of the steel after treatment are σm 760MPa, σ1570MPa, δ20.8%, V) 24.1%, KCV (Impact strength) was 2100 kJ/a.

The mechanical properties of the starting steel are σm 680MPa, δ7390MPa, δ19.2 %, weight 23.2%, and KCV (impact strength) 1980 kJ/g.

To approximate the condition of impact wear, two Tests were conducted in a ball mill consisting of a drum. The inside dimensions of the drum are diameter It was 20+ nm and 320 mm in length. Rotate the drum at a speed of 33 rpm I set it. Each drum contains 10 kg of steel balls (HRC50) with a diameter of 50 mm, with limited dimensions. 6 kg of crushed granite (approximately 10 to 20 mm), and the dimensions are 10 x 1 A specimen of treated steel measuring 0 x 25 mm was loaded. Abrasion resistance evaluation of ropes is based on relative wear resistance. It was done through wear and tear. The starting steel specimen was used as the standard.

As a result of the test, the wear resistance of the steel alloyed with nitrogen using the disclosed technology was lower than that of the starting steel. It was found that the wear resistance was improved by 30%.

Example 3 The composition is, in weight%, 3.98% carbon, 0.91% silicon, 0.52% manganese, Pig iron containing 0.110% phosphorus and 0.026% sulfur was melted in an induction furnace. molten metal It was poured from an induction furnace into a ladle with a capacity of 160 kg.

The temperature of the metal before treatment was 1260°C. Plasma generator ready for operation It was moved to a ladle and placed above the molten metal.

The plasma generator was started under the following operating conditions. That is, arc current 300 ~400A, voltage drop 180~250■, consumption of plasma forming gas 4g/ It is s. Plasma generating gas consists of argon (95%) and oxygen (5%) . The nozzle was immersed into the molten metal to a depth of 70-8 mm. At the same time, in the molten metal Finely divided slag-forming addition with a composition (wt%) of 80% lime and 20% fluorite (The size of the powder particles is selected based on the conditions that ensure the operability of the plasma generator.) ) was introduced. The total consumption of powder was 13 kg/l.

After the powder particles pass through the plasma arc, they are melted in a heated or molten state. Go into the metal. In the blowing zone, a gas pump containing a slag former and molten metal is used. Conditions are in place for effective stirring of the plasma jet. in plasma state The oxygen produced in the injection process forms a highly active iron-bearing lime-based slag in the molten metal. Contribute to As a result, in this case it occurs in the blowing zone and during the floating of slag particles. 'm, the subsequent dephosphorization process takes place rapidly and effectively. Continuous blowing for 3 minutes Later, the temperature of the molten pig iron rose to 1285°C.

Slag removal and deoxidation after processing molten metal by gas plasma jet , and metal casting operations.

The composition of the pig iron after treatment is, in weight percent, 3.60% carbon, trace amount of silicon, and manganese: Trace amounts were 0.01% phosphorus and 0.018% sulfur.

Industrial applicability The present invention can be applied to ordinary iron-carbon alloys, alloys containing expensive rare elements, and special alloys ( (e.g., wear-resistant alloys, corrosion-resistant alloys, heat-resistant alloys, high-temperature alloys, etc.), as well as special It is most advantageously used in the production of ferrous and non-ferrous alloys (e.g. aluminum alloys). can be done.

Procedural amendment September 1, 1986 Mr. Kunio Kogawa, Commissioner of the Patent Office 1.Display of the incident PCT/SU85100071 , name of invention Method of processing molten metal and means for its implementation 3. Person making the correction Relationship to the incident: Patent applicant Address: 8-10-5, Toranomon-chome, Minato-ku, Tokyo 105, Increased number due to amendment Light number 1 (increased from 1 to 2) 6, subject to correction (1) In the “Brief description of the drawings” column of the specification and “Best method for carrying out the invention” column (2) Scope of claims 7. Contents of correction (1) (i) rU-riJ on page 11, line 18 of the specification is corrected to “A-AJU” do.

(ii) "45%" in the first line of page 18 of the specification is corrected to "45 degrees J."

(2) Amend the scope of claims as shown in the attached sheet.

8. List of attached documents Tsumebo Hankai: l recitation The scope of the claims 1. Create a low-temperature plasma jet ( 2) and delivering the cold plasma jet (2) to the molten metal (3). In the molten metal processing method, the low temperature plasma is used to stir the molten metal (3). ・Give the molten metal (3) inside the body of the molten metal (3) on the surface side of the molten metal. The plasma jet (2 ) A molten metal processing method characterized by introducing the molten metal through the

2. Claim 1, characterized in that nitrogen-containing substances are not used as additives. the method of.

3. About 0.1 to about 1. Starch milled into particles with dimensions in the range of OH A method according to claim 1, characterized in that a lag-forming additive is used.

4. Oxygen in an amount of 0 to 100 vol. 1% of its own volume together with the slag-forming additive. The method according to claim 3, characterized in that the plasma forming agent containing the plasma forming agent is used. .

5. It is installed so that it can reciprocate in a vertical plane and is placed above the surface of the molten metal (3). It includes a plasma generator (1) for generating a low-temperature plasma jet (2) arranged. You will be playing the role of Natsu-te, who will collect 9 melts using the 0 plasma °jie''/t, which is made up of The plasma generator (1) includes a nozzle (5), and the nozzle (5) The end face faces the molten metal (3) and is further arranged to exhaust the low temperature plasma jet (2). having an inlet substantially equal to an outlet of the plasma generator (1) at an outlet position; The length of the part of the nozzle (5) immersed in the molten metal (3) is the same as that of the molten metal (3). 3) A molten metal processing hand characterized by having a height of about 0.1 to about 0.8 times the height of the column. Step.

6. The plasma generator (1) is installed so that it can move within a horizontal plane. The means according to claim 5, characterized in that:

7. Claim No. 1 characterized in that a torch-type plasma generator (1) is used. The means described in paragraph 5 or paragraph 6.

Tokuno(mouth [;3-500043 (8) 8, Plasma with external plasma arc As set forth in claim 5 or 6, the means of publication.

9, the nozzle (5) is provided with a plate (6) in the zone of the outlet; The rate (6) is a central hole coaxial with the internal hole of the nozzle, and a vertical through-hole to the pre. Any of claims 5 to 8 characterized in that it has means of publication.

10, the nozzle (5) has holes (24) for the introduction of additives in the zone of the inlet; The means according to claim 5, characterized in that it has the following.

Margin below

Claims (10)

[Claims] 1. A cold plasma jet (2 ) and delivering the cold plasma jet (2) to the molten metal (3). In the molten metal processing method, the low temperature plasma is used to stir the molten metal (3). The jet (2) is placed inside the body of the molten metal (3) on the side of the surface of the molten metal about 1 The plasma jet (2) is delivered at a speed of 500 m/s and the additive is A method for processing molten metal characterized by introducing the metal through the molten metal. 2. Claim 1, characterized in that a nitrogen-containing substance is used as an additive. the method of. 3. As an additive, it has been pre-milled into particles with dimensions ranging from about 0.1 to about 1.0 mm. A method according to claim 1, characterized in that a slag-forming additive is used. 4. Oxygen in an amount of 0 to 100 vol% of its own volume together with the slag-forming additive. The method according to claim 3, characterized in that the plasma forming agent containing the plasma forming agent is used. . 5. It is installed so that it can reciprocate in a vertical plane and is placed above the surface of the molten metal (3). It includes a plasma generator (1) for generating a low-temperature plasma jet (2) arranged. In the means for carrying out the molten metal processing method according to claim 1, comprising: The plasma generator (1) is equipped with a nozzle (5), and the nozzle (5) has an end surface. facing the molten metal (3) and further facing the discharge of the cold plasma jet (2). It has an inflow part substantially equal to the outflow part of the plasma generator (1) at a position. , the length of the part of the nozzle (5) immersed in the molten metal (3) is the molten metal (3). A molten metal processing means characterized in that the height of the column is about 0.1 to about 0.8 times the height of the column. 6. The plasma generator (1) is installed so as to move within a horizontal plane. The means according to claim 5, characterized in that: 7. Claim 1, characterized in that a torch-type plasma generator (1) is used. The means described in paragraph 5 or paragraph 6. 8. Characterized by using a plasma generator (1) with an external plasma arc The means according to claim 5 or 6. 9. The nozzle (5) is provided with a plate (6) in the zone of the outlet and the plate (6) The rate (6) is located in a central hole coaxial with the inner hole of the nozzle and in the plate (6). A claim characterized by having vertical passageways whose number increases from the center to the periphery. The means according to any one of the ranges 5 to 8. 10. The nozzle (5) has holes (24) for the introduction of additives in the zone of the inlet. The means according to claim 5, characterized in that it has the following.