JP2002205152A - Method for producing continuously cast product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a useful producing method for continuously cast product with which cast slabs having various kinds of alloy component compositions can be stably and cast continuously. SOLUTION: A consumable electrode is inserted into flux layer formed on molten steel surface in a continuous casting mold and the tip part of this consumable electrode is melted by supplying electric power into the flux layer and the alloy component contained in the consumable electrode is added into the molten steel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a continuous cast product having various alloy component compositions by adding a metal or a compound to molten steel in a mold in continuous casting of steel.

[0002]

2. Description of the Related Art In a steelmaking process, in order to separately produce steel slabs having various alloy component compositions, a method of continuously casting by adjusting the alloy component concentration for each molten steel ladle has been generally used. However, in such a method, the steel of the same composition must be manufactured at least for one full ladle.For example, when a molten steel ladle having a capacity of several hundred tons is used for an order of several tens of tons, a large amount of stock is required. It is difficult to manufacture small quantities of many types of steel, for example, it is necessary to set a long delivery time until the order is completed.In a series of slab production, slabs of various alloy component compositions are produced. A way to separate is being sought.

[0003] In order to solve such a problem, there has been proposed a method of producing slabs of various alloying component compositions from a full pot of molten steel by adding alloying components by continuous casting.

For example, Japanese Patent Application Laid-Open No. Hei 8-243687 proposes a method of injecting two types of molten steel having different alloy component compositions into a single mold as shown in FIG. However, in order to produce a slab having the desired alloy composition by this method, it is necessary to strictly control the ratio of the two types of molten steel to be injected into the mold. In other words, if one type of molten steel is used, it is possible to precisely measure the injection flow rate by controlling the slab drawing speed and the molten steel level in the mold. In such a case, it is difficult to separately measure the injection amount of molten steel, so that there is a problem that it is difficult to obtain a target alloy component composition. In addition, there is a problem that a large equipment change is required for the existing continuous casting equipment, and the equipment cost when a new one is installed is large.

The above publication also proposes a method in which an alloy component as shown in FIG. 1 (b) is contained in a flux and added to a molten steel surface in a mold. However, the flux suitable for the operation is restricted in the range of its component composition, and the alloy components that can be added to the flux are also limited, so that the types of slabs obtained are also limited.

Further, as shown in FIG. 1C, there has been proposed a method of directly supplying a wire containing an alloy element into molten steel in a mold. However, in this method, there are problems such as difficulties in controlling the alloy addition amount because it depends on the wire melting rate in the molten steel, and concentration unevenness due to the remaining molten wire in the molten steel. Further, since the heat source for melting the wire depends on the molten steel, the heat quantity of the molten steel is partially taken away and solidified to easily cause quality defects.

On the other hand, Japanese Patent No. 3012727 discloses that when adding a metal in the form of a wire to molten steel in a tundish, the amount of heat extracted from the molten steel is reduced by applying a current to the wire in advance and heating the wire. Methods have been proposed to prevent local cooling.

However, in the above method, the wire is merely heated from room temperature to the melting temperature, and the melting of the wire still depends on the calorific value of the molten steel. Cooling is inevitable. Further, in the above method, the amount of heat for melting the wire cannot be adjusted, so that the amount of the alloy added cannot be adjusted, and the composition of the alloy component of the obtained slab is also limited. Further, since the wire is directly added to the molten steel, there is a problem that the wire is left undissolved and the alloy component is likely to be uneven in the slab as described above. In addition, in the above method, electrodes other than the consumable electrode are directly inserted into the high-temperature molten steel, so that the durability of the electrodes is inevitably reduced, and the electrode material tends to become a contamination source of the molten steel. When carbon steel is used in casting steel, there is a problem that the C concentration in molten steel increases.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to stably produce slabs of various alloy component compositions by continuous casting. An object of the present invention is to provide a useful method for producing a continuous casting.

[0010]

The method of manufacturing a continuous cast product according to the present invention comprises inserting a consumable electrode into a flux layer formed on the surface of molten steel in a continuous casting mold, and placing the tip of the consumable electrode in the flux layer. The melting point of the consumable electrode is preferably performed by arc discharge between the tip of the consumable electrode and the molten steel, or resistance heating. .

In a preferred embodiment, a plurality of the consumable electrodes are supplied into the flux layer to supply a current between the consumable electrodes, and the current is supplied through a copper terminal.

In order to reduce the concentration gradient of the alloy components, the molten steel is applied with a frequency of 1 to 100 Hz and a magnetic flux density of 0.01 to 0.2 T
May be applied. In order to form a concentration gradient of the alloy component between the surface layer and the inside of the slab, a consumable electrode is inserted near the wall surface of the mold, and a magnetic flux density of 0.05 is applied to the molten steel.
A static magnetic field of up to 5 T may be applied, and a consumable electrode having a higher alloy element concentration than the molten steel injected into the mold is used as the electrode to form a slab surface layer having a higher alloy element concentration than the inside of the slab. By using a consumable electrode having a lower alloying element concentration than the molten steel injected into the mold, a slab surface layer having an alloying element concentration lower than the inside of the slab can be formed.

Further, the present invention includes a continuous cast product in which the alloying element concentration in the surface layer is higher or lower than that in the inside.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Under the above-described circumstances, the present inventors add alloying components, pure iron, or other compounds to molten steel in a continuous casting mold, thereby making continuous casting possible. We have conducted intensive research with the aim of realizing a method for stably producing slabs of various alloy component compositions. As a result, when the alloy component is added to the molten steel in the form of a consumable electrode, the consumable electrode is inserted into a flux layer formed on the surface of the molten steel in the continuous casting mold, and is melted by energization in the flux layer to be introduced into the molten steel. It has been found that if added, slabs having a variety of alloy component compositions can be manufactured by continuous casting by accurately adjusting the amount of the added alloy element without causing unnecessary unevenness in the slab.

The present invention, as shown in FIG.
The consumable electrode 4 is applied to the flux layer 3 formed on the surface of the molten steel 2
And the tip of the consumable electrode 4 is melted by energization in the flux layer 3 and added to the molten steel. That is, in the present invention, the consumable electrode 4 is
Rather than being immersed in the electrode, current is supplied while the tip of the consumable electrode 4 is held in the flux layer 3 on the surface of the molten steel. By supplying a current to the consumable electrode in this manner, a large voltage difference can be provided between the tip of the consumable electrode 4 and the surface of the molten steel, and an arc discharge 5 can be generated. The amount of heat can be obtained. Further, since a resistance heating effect can be obtained in a flux layer formed of an oxide or the like having a large electric resistivity, a larger heat generation effect can be obtained.

By obtaining such a large heat generation effect, it is possible to supply both the amount of heat required to raise the temperature of the consumable electrode from room temperature to the melting temperature and the amount of heat required to melt it as electric energy. As a result, the melting ability of the consumable electrode, that is, the ability to add alloy components, can be dramatically improved as compared with the case where the consumable electrode is immersed in molten steel and melted. As described above, in the method of the present invention, the heat source for melting the consumable electrode does not depend on molten steel, so that stable operation can be performed without changing the molten steel temperature. Further, by controlling the amount of current, the amount of melting of the consumable electrode, that is, the amount of addition of an alloy or the like can be accurately adjusted.

If the thickness of the flux layer is too small, it is not possible to ensure the meniscus heat retention and sufficiently prevent oxidation from the molten steel surface. Therefore, the thickness of the flux layer is preferably set to 10 mm or more.

The consumable electrode may be made of various materials depending on the alloy composition of the cast slab to be produced. For example, iron-silicon alloy, iron-manganese alloy, iron-
Phosphorus alloy, nickel, chromium, molybdenum, copper, niobium,
Titanium, zirconium and the like are used, and those further added with aluminum, lead, rare earth element, boron, sulfur and the like can be used. In order to obtain a layer having a low alloy component concentration, pure iron may be used as a consumable electrode. Examples of the shape of the consumable electrode include a wire, a ribbon, and a rod.

In carrying out the present invention, it is possible to add an alloy to molten steel by using one consumable electrode. However, when one consumable electrode is used, another alloy is used for forming an electric circuit. It is necessary to immerse the electrode in molten steel. Then, the durability of the electrode and the contamination of the molten steel by the electrode material become a problem. For example, when a carbon electrode is used as another electrode, it is difficult to use the carbon material stably for a long time because carbon of the material easily melts into the molten steel. Further, the dissolved carbon is eluted into the molten steel, so that, for example, the carbon concentration is 0.005.
% Or less, the carbon concentration is unnecessarily increased when casting ultra-low carbon steel of less than 10%.

Therefore, it is desirable to insert a plurality of consumable electrodes. By using a plurality of consumable electrodes, it is not necessary to use an electrode other than for adding an alloy element, which can prevent the durability of the electrode and the contamination of molten steel by the electrode material, and also increases the total amount of the alloy element added. You can do it.

Although a direct current can be used for energization, it is desirable to use a single-phase or multi-phase alternating current in order to reduce the variation in voltage between the electrodes. Further, in order to reduce the electric resistance between the consumable electrode and the terminal and to supply electricity reliably, it is desirable to supply power to the consumable electrode via the copper terminal 6 as shown in FIG. May be applied.

When applying an alternating current, a single-phase alternating current may be applied to i = 2n (n is an integer) consumable electrodes, or 3 = 3n (n is an integer) consumable electrodes. A phase alternating current may be supplied.

The value of the current flowing per consumable electrode is:
200 to 2000 A, depending on the electrode material and electrode cross-sectional area
It is desirable that If the current value is too low, a large number of electrodes are required to secure the alloying component addition capability, and the equipment becomes complicated, and if the current value is too high, it becomes difficult to uniformly mix the alloying components. is there.

FIG. 3 shows that when a slab having a width of 1500 mm is cast under a condition of a casting speed of 1.8 m / min, two and four electrodes are respectively placed at a position of about 120 mm inside the mold wall.
When a static magnetic field of 0.3 T is applied to a region having a depth of 500 to 700 mm from the surface of the molten metal in the mold while the alloy component (Ni) is intensively added to the surface layer portion by inserting eight of them, a per-electrode per electrode It is the graph which showed the relationship between the current value and the Ni concentration of the slab surface layer part according to the number of electrodes. As is clear from this figure,
It can be seen that increasing the current value and increasing the number of electrodes can dramatically increase the alloy addition capacity.

In a situation where the molten steel surface level of the molten steel to be injected changes and the tip of the consumable electrode melts, the tip of the consumable electrode is not immersed in the molten steel surface. It is necessary to control the distance from the molten steel surface to a constant value. As a specific control method, for example, when the interval is increased, the dissolution rate of the consumable electrode is reduced to reduce the interval,
When the interval becomes small, there are methods such as increasing the dissolving speed of the consumable electrode, and it is desirable to perform these by automatic control. The following method can be cited as one form of automatic control. That is, the distance between the tip of the consumable electrode and the molten steel surface is
Since it is proportional to the electrical resistance (= voltage / current) of the system,
For example, if the voltage is kept constant, when the interval is reduced, the electric resistance is reduced and the current is inevitably increased, so that the dissolution speed is increased and the interval is expanded. Also, when the interval is widened, the electric resistance increases and the current value inevitably decreases, so that the dissolution rate decreases and the interval narrows.

In order to obtain a slab having a uniform alloy composition, it is necessary to sufficiently stir and mix the molten steel after the addition of the alloy to eliminate the unevenness in the concentration of the molten steel. In particular, when the alloy is added to the molten steel in the mold, it is important to stir and mix the molten steel because the concentration unevenness of the molten steel tends to directly cause the concentration unevenness of the slab. As a method of stirring, there is gas stirring performed by blowing an inert gas such as Ar into molten steel, and the like, but to obtain a more stable stirring effect, it is desirable to perform electromagnetic stirring using a moving magnetic field.

The frequency of the moving magnetic field is preferably set to 1 Hz or more, and more preferably 2 Hz or more, because the stirring power is weakened if it is too low. Further, even if the frequency is too high, the penetration of the magnetic field into the molten steel is weakened. Therefore, the frequency is preferably 100 Hz or less, more preferably 4 Hz or less.

If the magnetic flux density of the moving magnetic field is too low, the stirring power is weak and the alloy concentration in the molten steel is not uniform.
It is preferably at least 1T, more preferably at least 0.0T.
5T or more. Further, even if the magnetic flux density is too large, the molten steel surface is disturbed and stable casting is difficult to perform. Therefore, the magnetic flux density of the moving magnetic field is preferably 0.2 T or less, more preferably 0.12 T or less.

If the region of the electromagnetic stirring is too deep from the surface of the molten metal, the effect of stirring the surface of the molten steel is weakened and the concentration unevenness is likely to occur. Therefore, the region within a depth of 300 mm from the surface of the molten steel is sequentially stirred. It is desirable.

In order to make the alloy concentration distribution uniform, it is also effective to swing the consumable electrode in the flux layer perpendicularly to the casting direction as shown in FIG.

When an alloy is added to molten steel in a mold using a consumable electrode, unevenness in the concentration of the molten steel tends to occur, and the composition of the molten steel tends to be more uneven in the upper part of the mold immediately after the addition of the alloy than in the lower part. Also, the surface layer of the slab solidifies at the top of the mold and the inside of the slab solidifies at the lower side, but in the present invention, by utilizing these properties, the concentration gradient of the alloy component between the surface layer and the inside of the slab is reduced. Thus, it was possible to manufacture a continuous cast product in which only the surface layer portion had a beneficial alloy component composition.

In order to positively form such a concentration gradient of the alloy component, the above consumable electrode may be inserted near the wall surface of the mold, but it is necessary to make the concentration distribution in the slab width direction in the surface layer uniform. For this reason, it is preferable to insert near the corner of the mold.

In order to suppress the mutual stirring of the upper and lower portions of the molten steel in the mold, it is effective to apply a static magnetic field to the molten steel.
If the magnetic flux density of the static magnetic field is too small, a sufficient stirring suppression effect cannot be obtained, so that it is preferably 0.05 T or more, more preferably 0.15 T or more. Even if the magnetic flux density is too large, an appropriate mixing suppression effect cannot be obtained, and equipment cost and power consumption for generating the magnetic flux increase, so that the magnetic flux density of the static magnetic field is preferably 5T or less, Preferably it is 0.5T or less.

It is preferable that the static magnetic field acts below the molten steel surface and above the immersion nozzle discharge hole through which molten steel flows into the mold.

As one mode of providing a concentration gradient of the alloy component between the surface layer portion and the inside of the slab, there is a case where a slab surface layer having a higher alloy element concentration than the inside of the slab is formed.

For example, when improving the corrosion resistance of steel for thick plates, alloy components such as Ni, Cr, P, Ti, and Cu are generally added, but the corrosion resistance is often required only on the surface layer of the slab. Therefore, if the above element is added to the molten steel as a consumable electrode from the vicinity of the wall surface of the mold, the amount of alloy added to the inside of the slab can be suppressed while ensuring the corrosion resistance of the surface layer of the slab. Therefore, compared to a conventional product in which the above elements are uniformly added to the inside of the cast slab, the amount of the expensive alloy element used can be suppressed, and a steel slab with high corrosion resistance can be provided at lower cost. is there.

In order to form a slab surface layer having a higher alloying element concentration than the inside of the slab, a consumable electrode having a higher alloying element concentration than the molten steel injected into the mold may be inserted near the wall surface of the mold. In addition to the purpose of improving the corrosion resistance, in order to increase the hardness of the surface layer of the steel material, C, Mn, Cr, Mo, V, Nb
A consumable electrode containing such elements may be used. Further, even when Pb, rare earth elements, B, S, etc. are added in order to enhance the machinability of the entire steel material, compared with the case where these elements are added to a molten steel pot and cast, the above-mentioned phenomenon caused by evaporation and floating occurs. The loss of the alloy element can be reduced, and the yield of the added alloy element can be increased. As a method of forming a slab surface layer having a higher alloy element concentration than the inside of the slab, in addition to the above-described method, a method of inserting a consumable electrode having a lower alloy element concentration than molten steel injected into the mold near the center of the mold is cited. Can be

As another mode for providing a concentration gradient of the alloy component between the surface layer portion and the inside of the slab, there is a case where a slab surface layer having a lower alloy element concentration than the inside of the slab is formed.

For example, an alloy such as Si may be added in a large amount for the purpose of improving the workability of steel for thin sheets. However, while the workability is improved, the adhesion of plating when zinc is plated is reduced. There is a problem of doing. Therefore, as a steel with improved workability and plating adhesion at the same time, S
A steel slab having a low i concentration and a high internal Si concentration is required. In such a case, while injecting molten steel having a high Si concentration into the mold from a molten steel pot, steel containing no Si is used as a consumable electrode to form a mold of the mold. By adding to the molten steel from the vicinity of the wall surface, a steel slab having both of the above characteristics can be obtained.

In order to form a slab surface layer having a lower alloy element concentration than the inside of the slab, a consumable electrode having a lower alloy element concentration than the molten steel injected into the mold may be inserted near the wall surface of the mold. Another method is to insert a consumable electrode having a higher alloying element concentration than the molten steel injected into the mold near the center of the mold. When the alloy element is added to the entire slab, cracks may occur inside the slab during casting due to the added alloy component, but the alloy is concentrated on the slab surface layer by the above method. If added, the occurrence of the above-mentioned defects can be prevented.

[0041]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples, and the present invention is not limited thereto. Modifications can be made and implemented, all of which are included in the technical scope of the present invention. (1) Embodiment of Supplying Consumable Electrodes When continuously casting a slab having a constant width (1230 mm) while changing the casting speed as shown in the upper diagram of FIG.
A wire-shaped Ni consumable electrode wound around a reel
Using an automatic electrode feeder, the feed rate was adjusted so as to be linked to the feed rate of the molten steel, and the feed rate was continuously supplied into the flux layer in the mold. Ni was used as an alloy component, and the concentration at a position 5 mm deep from the slab surface was such that the casting speed was 1.8 m / m.
Min was added to be 0.1 mass%.
Each reel was set on an insulating frame to ensure electrical insulation between the reels.

A comparative example was a case where continuous casting was performed in the same manner as described above, except that the supply speed of the consumable electrode was kept constant irrespective of the continuous casting speed.

FIG. 5B shows the Ni concentration (mass) at a position 5 mm deep from the slab surface where the casting speed varies when continuous casting is performed with or without the above-mentioned electrode supply speed control.
%) Shows a graph showing the change of The Ni concentration was determined by cutting a sample from a narrow surface of the cast slab slab from the narrow surface at a depth of 5 mm with a drill and performing chemical analysis. FIG. 5 shows the subtotal 10 for each of the Examples and Comparative Examples, 15 g each in the casting direction of the slab and 5 g from both narrow surfaces.
g is a result of measuring a total of 30 samples.
From this figure, it can be seen that by adjusting the supply speed of the consumable electrode, that is, the amount of Ni added, according to the change in the continuous casting speed, the change in the Ni concentration at a certain depth from the slab surface can be suppressed.

As shown in the lower diagram of FIG. 5, the alloy component concentration in the molten steel takes time from the time immediately after the start of casting to reach a predetermined alloy component concentration. In order to improve the yield by keeping the Ni concentration at a specific position in the vertical slab cross section at an early stage to improve the yield, immediately after the alloy addition is started, the supply rate of the consumable electrode is increased, and the alloy component concentration of the molten steel is rapidly increased. Automatic control may be performed so that the supply speed is switched to the supply speed according to the molten steel injection flow rate when the predetermined concentration is reached.

In this embodiment, the width of the mold during casting is fixed. However, even when the width of the mold is changed during casting, the mold width is proportional to {(casting speed + metal surface level rise speed) × mold width × mold thickness}. If the supply speed of the consumable electrode is linked to the molten steel injection flow rate, for example, if the molten steel injection amount into the mold is automatically controlled so that the level of the molten metal in the mold is constant by an eddy current level meter, The concentration of the added alloy in the cross section of each slab in the casting direction can be made constant. When the level of molten steel in the mold changes, by controlling the molten steel injection flow rate according to the change in the level of the molten steel, it is possible to more accurately suppress the variation in the concentration of the added alloy in the cross section of each slab in the casting direction. be able to. (2) Example of Method for Stirring and Mixing Molten Steel The location of electrodes, the presence or absence of a moving magnetic field, and the presence or absence of a static magnetic field are determined by the non-uniformity of the alloy concentration in the slab in the width direction and the alloy concentration of the surface layer with respect to the inside The effect on the water was examined.

The electrode may be placed on only one side or both sides of the slab.
A magnetic field circling horizontally at 3 Hz was applied to a range up to 00 mm. In addition, a magnetic field was applied as a static magnetic field to a depth of 500 to 700 mm from the inner surface of the mold. The evaluation of the alloy concentration distribution of the obtained slab was performed by using a, b, and c shown in FIG.
Samples were taken from the three locations described above, and the Ni concentration (mass%) of each sample, ie, Ca, Cb, Cc, was measured and inserted into the following equations (1) and (2). The orientation nonuniformity, and B; the alloy enrichment of the surface layer with respect to the inside was determined. The results are shown in Table 1.

A = | Ca−Cb | / (Ca + Cb) (1) Alloy concentration of surface layer with respect to the inside; B = (Ca + Cb) / 2Cc (2)

[0048]

[Table 1]

No. 1 in Table 1. From FIG. 4, it is possible to suppress the generation of a concentration gradient of the alloy component by applying a moving magnetic field that horizontally turns an area within 300 mm from the surface of the mold inside with the disposing place of the consumable electrode on both sides, and can suppress the occurrence of a concentration gradient of the alloy component. It turned out to be obtained. No. 5 and No. 5 From 6, it is necessary to increase the alloy concentration of the surface layer inside the slab.
It has been found that it is sufficient to apply a static magnetic field to the molten steel in the mold to suppress the molten steels in the upper and lower regions of the static magnetic field application region from being mixed with each other.

[0050]

The present invention is constituted as described above, and is formed on the surface of the molten steel in the continuous casting mold when adding an alloy component, pure iron, or other compounds to the molten steel in the continuous casting mold. By inserting a consumable electrode containing the above-mentioned alloy component and the like into the flux layer thus melted and added to the molten steel by energization in the flux layer, the amount of the added alloy element can be adjusted widely and accurately, and various kinds of continuous casting can be performed. It was possible to produce slabs of various alloy component compositions.

Also, by inserting a consumable electrode having a higher or lower alloy concentration than the molten steel to be injected into the vicinity of the mold to make the alloy concentration in the surface layer higher or lower than that in the inside, it is beneficial only to the surface layer. Thus, an economical billet having various layers can be manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a conventional example of a method of adding an alloy component by continuous casting, wherein (a) shows a method of adding an alloy component having different compositions.
(B) shows a method of supplying an alloy component by adding it to a flux, and (c) shows a method of directly supplying an alloy wire into molten steel in a mold.

FIG. 2 is a schematic view illustrating a method for adding an alloy component into a continuous casting mold according to the present invention.

FIG. 3 is a graph showing a relationship between a current value and a Ni concentration in a surface layer portion of a slab.

FIG. 4 is a cross-sectional view of a mold perpendicular to a casting direction illustrating a supply position of a consumable electrode.

FIG. 5 shows a variation in slab speed of Ni at a constant depth from the slab surface.
6 is a graph showing the influence on the concentration (mass%) depending on whether or not supply speed control of a consumable electrode is performed.

FIG. 6 is a cross-sectional view of a slab perpendicular to a casting direction showing an alloy concentration measurement position in an example.

[Explanation of symbols]

 Reference Signs List 1 mold 2 molten steel 3 flux layer 4 consumable electrode 5 arc discharge 6 copper terminal

Continued on the front page (72) Inventor Hideo Mori 1 Kanazawa-cho, Kakogawa City, Hyogo Prefecture Inside Kobe Steel Kakogawa Works (72) Inventor Yuki Yamamoto 1 Kanazawa-cho, Kakogawa City, Hyogo Prefecture Kobe Steel Corporation Kakogawa Co. F term in steelworks (reference) 4E004 AA09 MB12 MB14 NB01 NC01

Claims (9)

[Claims] A continuous electrode characterized in that a consumable electrode is inserted into a flux layer formed on the surface of molten steel in a continuous casting mold, and the tip of the consumable electrode is melted by energization in the flux layer and added to the molten steel. Manufacturing method for castings. 2. The method according to claim 1, wherein melting of the consumable electrode is performed by resistance heating or arc discharge between a tip of the consumable electrode and molten steel. 3. The consumable electrode according to claim 1, wherein a plurality of said consumable electrodes are supplied into said flux layer to supply a current between said consumable electrodes.
3. The method for producing a continuous casting according to item 1. 4. The method for producing a continuous casting according to claim 1, wherein the power supply to the consumable electrode is performed via a copper terminal. 5. The continuous cast product according to claim 1, wherein a moving magnetic field having a frequency of 1 to 100 Hz and a magnetic flux density of 0.01 to 0.2 T is applied to the molten steel to reduce the concentration gradient of the alloy component. Manufacturing method. 6. Inserting a consumable electrode near a wall surface of a mold,
The production of a continuous casting according to any one of claims 1 to 4, wherein a static magnetic field having a magnetic flux density of 0.05 to 5 T is applied to the molten steel to form a concentration gradient of an alloy component between the surface layer portion and the inside of the slab. Method. 7. The production of a continuous cast product according to claim 6, wherein a slab surface layer having a higher alloy element concentration than the inside of the slab is formed by using a consumable electrode having a higher alloy element concentration than molten steel injected into a mold. Method. 8. The production of a continuous cast product according to claim 6, wherein a consumable electrode having a lower alloy element concentration than the molten steel injected into the mold is used to form a slab surface layer having a lower alloy element concentration than the inside of the slab. Method. 9. A continuous cast product wherein the surface layer portion has an alloy element concentration higher or lower than the inside.