JP2006312200A - Continuous casting powder and continuous casting method for al-containing ni-based alloy - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide continuous casting powder for Al-containing Ni-based alloy to perform smooth continuous casting and a method for continuously casting a slab free from surface defects using the powder. <P>SOLUTION: The powder for continuously casting a molten steel containing more than 0.8 mass% to 3.5 mass% Al contains 20-30 mass% CaO, 30-40 mass% SiO<SB>2</SB>, 1-10 mass% Na<SB>2</SB>O, 0.5-5 mass% Al<SB>2</SB>O<SB>3</SB>, 10-15 mass% F, 0.1-8 mass% MgO, 0.5-5 mass% MnO, 4-10 mass% BaO, 4-10 mass% Li<SB>2</SB>O, 0.5-3 mass% C, and has a basicity controlled to 0.5<CaO/SiO<SB>2</SB><1.0, a viscosity of 0.4 to 2 poise at 1,300°C, a solidification temperature of 850°C to 1,100°C, and such a property that one side of the mold powder contacting with a mold is crystallized when the mold powder is poured between the mold and a solidified shell. The method for continuously casting the molten steel using the powder is also provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a continuous casting powder used when continuously casting an Al-containing Ni-based alloy and a method for continuously casting a slab having no surface defects using the powder.

Continuous casting powder used when continuously casting a Ni-based alloy generally contains carbon as an aggregate in addition to oxides such as CaO, SiO ₂ , Na ₂ O, Al ₂ O ₃ , F, etc. Is used. The characteristics of these powders are designed such that the oxide melts by receiving heat from the molten metal and flows between the mold and the solidified shell to play a role of lubrication and heat removal adjustment. Carbon as an aggregate is added to adjust the melting rate.

However, in the case of such continuous casting powder, when used for continuous casting of molten alloy containing active Al, the Al reacts with SiO ₂ contained in the melted powder to react with Al ₂ O ₃ (oxide). This Al is transferred into the powder (slag). For this reason, there has been a problem that the powder composition changes greatly, and physical properties such as viscosity and solidification temperature change, which makes it unsuitable for continuous casting. As a result, surface defects such as depletion, vertical cracks, horizontal cracks, and bleeding were caused in the slab (slab), sometimes leading to a breakout and stopping the operation.

In order to deal with such problems, conventionally, for example, in Patent Document 1, casting is performed using powder having a basicity (CaO / SiO ₂ ) of 0.4 or less and a solidification temperature of 790 to 835 ° C., and the composition of the powder changes. We have proposed a technology that ensures that the physical property value is within the proper range even if the problem occurs. However, since this technology induced a lower basicity and solidification temperature, the crystallinity of the powder was lost and it became vitrified, and the inflow of molten powder between the solidification shell and the copper mold was greatly increased. As a result, there is a problem that non-uniform cooling is caused.

Patent Document 2 proposes a technique of casting using powder whose basicity (CaO / SiO ₂ ) is adjusted as high as 1.8 to 2.5. When the basicity of the powder is increased in this way, the reaction between the molten steel components Ti and Al and the SiO ₂ in the powder is suppressed, and changes in the physical properties of the powder can be prevented. However, since this powder has a high basicity, the coagulation temperature is increased, the viscosity in the working temperature range is lowered by that amount, and it is not possible to secure an appropriate amount of powder flow, which causes sticking and the like. There was a fear.

In Patent Document 3, Ti: 0.08~3.0mass%, Al : the molten steel containing 0.02～0.8Mass%, basicity _{0.7 <CaO / SiO 2 <1.8} , overheating When the temperature is set to 5 to 50 ° C., a technique for suppressing the pickup of TiO ₂ and Al ₂ O ₃ in the powder within the casting suitability range (30 mass% or less in total) is disclosed. However, when the Al concentration in the molten steel exceeds 0.8 mass%, this technique leads to an increase in solidification temperature and viscosity due to remarkable pickup of Al ₂ O ₃ , resulting in insufficient inflow of powder and sticking. There was a problem of starting up.
Japanese Patent Laid-Open No. 4-100600 JP-A-7-116797 JP 2003-94150 A

  As mentioned above, the slabs with poor surface properties still have the conventional technology, causing insufficient or excessive inflow of molten powder between the solidified shell and the mold, causing breakout, sticking, or non-uniform cooling. There was a problem of becoming.

  Accordingly, an object of the present invention is to provide an Al-containing Ni-based alloy continuous casting powder that is effective for performing smooth continuous casting without the above-mentioned problems of the prior art, and a surface using the powder. The object is to propose a method for continuously casting slabs without defects.

In the research for the realization of the above-mentioned object, the inventors first of all, what kind of powder is used when continuously casting a Ni-based alloy containing Al: more than 0.8 mass% and not more than 3.5 mass%. As to whether or not is preferable, a solidification test and thermal analysis of the molten metal were performed. As a result, the viscosity at 1300 ° C. is 0.4 to 2 poise, the solidification temperature is 850 to 1100 ° C., and there is no particular limitation, but caspidine, CaO—SiO ₂ —Al ₂ O ₃ system, Li ₂ O—SiO _As long as the powder has a characteristic of crystallizing a crystal phase containing one or more of _2- Al ₂ O ₃ system or Li ₂ O—BaO—CaO—SiO ₂ —Al ₂ O ₃ system, an Al-containing Ni-based alloy Has been found to be able to be cast smoothly without surface defects.

Next, the inventors measured the viscosity and coagulation temperature in order to investigate what component composition should be used for the powder having the above physical properties. As a result, what is considered to be preferred _{powder, CaO: 20~30mass%, SiO 2} : 30~40mass%, Na 2 O: 1~10mass%, Al 2 O 3: 0.5~5mass%, F: 10~15mass%, MgO: 0.1~8mass%, MnO: 0.5~5mass%, BaO: 4~10mass%, Li 2 O: was found to be that of the component composition containing 4～10Mass% .

Furthermore, the inventors also examined suitable conditions for continuously casting the Al-containing Ni-based alloy. That is, using a high-frequency induction furnace, a reaction experiment was performed between continuously cast powder having various component compositions and molten alloy containing Al: more than 0.8 mass% and not more than 3.5 mass%. As a result, when the superheat degree of the molten metal to be cast is 50 ° C. or less and the powder is adjusted so that the basicity satisfies 0.5 <CaO / SiO ₂ <1.0, It has been found that the Al ₂ O ₃ pickup can be within the casting suitability range (30 mass% or less).

  And the continuous casting powder developed based on such knowledge was finally used in an actual machine, and test casting was performed under various casting conditions. As a result, a continuous casting powder containing 0.5 to 3 mass% of C as an aggregate is used in addition to the above component composition, the superheat degree of the molten metal is set to 5 to 50 ° C., and the drawing speed is controlled to 600 to 900 mm / min. As a result of continuous casting, it became clear that both the melting rate of the powder and the inflow amount of the molten powder could be controlled within a suitable range.

That is, the present invention was developed based on the above knowledge and test results, and the gist of the present invention is that steel containing Al: more than 0.8 mass% and not more than 3.5 mass%. a powder for use in the continuous casting, the _{powder, CaO: 20~30mass%, SiO 2} : 30~40mass%, Na 2 O: 1~10mass%, Al 2 O 3: 0.5~5mass%, F: 10~15mass%, MgO: 0.1~8mass %, MnO: 0.5~5mass%, BaO: 4~10mass%, Li 2 O: 4~10mass%, C as aggregate: 0.5 has a component composition containing 3 mass%, and a viscosity at basicity _{0.5 <CaO / SiO 2 <1.0,1300} ℃ is 0.4~2poise and coagulation temperature 8 Continuous for Al-containing Ni-based alloys characterized by having a property of 0 to 1100 ° C. and further having a property of crystallizing a crystal phase on the side in contact with the mold when it flows between the mold and the solidified shell It is a casting powder.

In addition, the above-mentioned powder of the present invention is prepared by caspidine, CaO—SiO ₂ —Al ₂ O ₃ system, Li ₂ O—SiO ₂ —Al ₂ O ₃ system or LI ₂ O—BaO—CaO—SiO ₂ —Al during solidification. It is desirable to crystallize a crystal phase containing one or more of ₂ O ₃ system, and the thickness of the crystal phase is 10 to 80% of the total powder layer flowing between the mold and the solidified shell. It is effective to make the thickness equivalent to.

  Further, the present invention provides C ≦ 1.0 mass%, Si ≦ 2.0 mass%, Mn ≦ 2.0 mass%, Cu: 20 to 40 mass%, Al: more than 0.8 mass% and 3.5 mass% or less, Fe ≦ 3.0 mass%, the molten alloy consisting of Ni and inevitable impurities as the balance, or C ≦ 1.0 mass%, Si ≦ 2.0 mass%, Mn ≦ 2.0 mass%, Cr: 20-30 mass%, Al: Using the above continuous casting powder, a molten alloy consisting of 0.8 to 3.5 mass%, the balance being Ni and inevitable impurities, under conditions of a drawing speed of 600 to 900 mm / min and a molten metal superheat degree of 5 to 50 ° C. A continuous casting method is proposed.

In the method of the present invention, the pick-up of Al ₂ O ₃ into the powder during continuous casting can be controlled to 30 mass% or less by setting the basicity of the powder to 0.5 to 1.0.

  If the powder of the present invention according to the configuration described above is used, a continuous casting slab of an Al-containing Ni-based alloy having no surface defects such as depletion, vertical cracking, lateral cracking, and bleeding can be obtained. Further, according to the continuous casting method of the present invention, Ni-base alloy molten metal can be continuously cast without causing powder inflow failure and causing sticking, non-uniform cooling, or the like. As a result, according to the present invention, the grinding yield can be improved, and the productivity can be improved and the manufacturing cost can be reduced.

The continuous casting powder (hereinafter also simply referred to as “powder”) according to the present invention has been developed through experiments as described above, and is basically CaO—SiO ₂ —Al ₂ O ₃ —BaO—Li. It is composed of a ₂ O—MgO—MnO—Na ₂ O—F system. And this powder has the characteristics that the viscosity at 1300 ° C. is 0.4 to 2 poise, the solidification temperature is 850 to 1100 ° C., and it is between the mold and the solidification shell, and at least a part thereof is crystallized. Is a feature. Hereinafter, the reason why the physical properties of the powder of the present invention are limited as described above will be described.

Viscosity at 1300 ° C .: 0.4-2 poise
If the viscosity of the powder is less than 0.4 poise, the powder will flow in excessively, causing depletion, vertical cracking, horizontal cracking, and bleeding. On the other hand, if the viscosity exceeds 2 poise, the inflow is insufficient and sticking occurs. In any case, a slab surface defect is generated, and the yield of the slab is increased and the yield is lowered. In the worst case, it may cause a breakout. For this reason, the viscosity of the molten powder at 1300 ° C. is set to 0.4 to 2 poise.

Solidification temperature: 850-1100 ° C
If the solidification temperature of the powder is lower than 850 ° C., it will cause excessive powder inflow, causing depletion, vertical cracking, horizontal cracking, bleeding, etc. On the other hand, if the temperature exceeds 1100 ° C., it will lead to insufficient inflow and sticking In any case, surface defects of the slab will be generated, the amount of slab grinding will increase, the yield will decrease, and in the worst case, breakout may occur. Therefore, in the present invention, the molten powder solidification temperature is set to 850 ° C to 1100 ° C.

Crystallization Behavior In general, oxides or oxyfluorides are sometimes crystallized or vitrified during solidification. The molten powder flows between the solidified shell and the mold inner wall surface during casting, and at least a part of the powder is solidified to form a solidified layer. At this time, if the powder is crystallized without vitrification, the powder film is uniformly formed, and uniform cooling of the slab is realized. Therefore, as a characteristic of the powder, at the time of solidification, at least the side in contact with the mold needs to be crystallized with a predetermined thickness. The composition of the crystal phase generated when the powder solidifies is caspidine, CaO—SiO ₂ —Al ₂ O ₃ system, Li ₂ O—SiO ₂ —Al ₂ O ₃ system, or LI ₂ O—BaO—CaO. It is desirable that it contains one or more of —Al ₂ O ₃ system.

Of the solidified layer of the powder layer, the crystal phase generated on the side in contact with the mold is set to a thickness corresponding to 5 to 90% of the total thickness of the solidified layer. The reason for the powder solidified layer having such a crystal phase is that when the proportion of the crystal phase is less than 5%, it becomes almost the same as the glass state. On the other hand, when the ratio of the thickness of the crystal phase exceeds 90%, the total thickness of the molten powder becomes thin, and the lubricity of the solidified shell decreases. In these cases, the risk of causing surface defects is extremely high. Therefore, the powder according to the present invention is such that the proportion of the crystallized powder flowing between the inner wall surface of the mold and the solidified shell occupies 5 to 90% of the total thickness of the solidified layer. For the ratio of the crystal layer, CaO and _{SiO 2, Al 2 O 3,} Na 2 O, can be achieved by adjusting the content of F. The ratio of the crystal layer to the solidified layer is about 10 to 80%, preferably about 15 to 75% in order to further improve the above effect. The total thickness of the solidified layer of the powder flowing between the mold and the solidified shell is not particularly limited, but is preferably about 0.5 to 3 mm.

Then, powder of the present invention, the component _{composition, CaO: 20~30mass%, SiO 2} : 30~40mass%, Na 2 O: 1~10mass%, Al 2 O 3: 0.5~5mass%, F: 10~15mass%, MgO: 0.1~8mass %, MnO: 0.5~5mass%, BaO: 4~10mass%, Li 2 O: 4~10mass%, C: the 0.5～3Mass% Is. The reason for using this component composition is the experimental numerical range that the inventors have learned in many casting experiments, because it is the component composition necessary to achieve the physical property values and crystallization behavior described above. is there.

  Of the component composition of the powder, MgO has the effect of increasing the solidification temperature. However, if the MgO content exceeds 8 mass%, the solidification temperature exceeds 1100 ° C. and is too high, whereas if it is less than 0.1 mass%, the solidification temperature is too low and less than 850 ° C. The MgO content is preferably 0.2 to 7 mass%.

  C is added to control the melting rate of the powder, and if it is less than 0.5 mass%, the melting rate is too high, resulting in excessive inflow, and surface defects such as depletion, vertical cracks, vertical cracks, and bleeding. Occurs and the yield of slabs decreases. On the other hand, if the C exceeds 3 mass%, the melting rate becomes too slow and the inflow cannot catch up, surface defects such as sticking and bleeding tend to occur, and the yield of the slab decreases. Causes a breakout in the worst case.

Basicity: 0.5 <CaO / SiO ₂ <1.0
When the basicity of the powder is 0.5 or less, the activity of SiO _{2 in} the powder becomes high, so that the pickup of Al ₂ O _{3 in} the powder exceeds 30 mass% by the reaction shown in the following formula (1). It tends to be highly vitrified and increase in viscosity. If the Al ₂ O ₃ pickup amount exceeds 5 mass%, the physical property value deviates from the casting suitability range. As a result, surface defects such as sticking occur, the amount of slab grinding increases, and the yield decreases.
On the other hand, when the basicity of the powder is 1.0 or more, the viscosity decreases, surface defects such as depletion, vertical cracking, horizontal cracking, and bleeding occur, and the above physical property values cannot be obtained. Therefore, in the present invention, the basicity of the powder is set to be more than 0.5 and less than 1.0.
3 (SiO ₂ ) +4 Al = 2 (Al ₂ O ₃ ) +3 Si (1)
In addition, the inside of () is a component in powder, and an underline part represents the component in molten steel.

The present invention also proposes a method for smoothly continuously casting an Al-containing Ni-based alloy using the powder. Examples of target alloys in which the powder is effectively used include C ≦ 1.0 mass%, Si ≦ 2.0 mass%, Mn ≦ 2.0 mass%, Cu: 20 to 40 mass%, and Al: 0.8 to 3 .5 mass%, Fe.ltoreq.3.0 mass%, the balance being Ni and an inevitable impurity alloy, or C.ltoreq.1.0 mass%, Si.ltoreq.2.0 mass%, Mn.ltoreq.2.0 mass%, Cr: 20 to 30 mass %, Al: more than 0.8 mass% and 3.5 mass% or less, with the balance being Ni and inevitable impurities. When continuously casting these molten alloys, the slab drawing speed is 600 to 900 mm / min, and the molten metal superheat is 5 to 50 ° C. It is possible to control the amount of Al ₂ O ₃ pickup in the powder to ₃₀ mass% or less when the continuous casting is performed using the above powder under such conditions, and as a result, surface defects are eliminated. 90% or more of the yield associated with slab grinding can be secured. Below, the limitation reason is demonstrated about each casting condition.

  Regarding the alloy component, C is useful for maintaining the strength of the material, but when it exceeds 1.0 mass%, it becomes brittle. Si and Mn are elements useful for deoxidation, and if they exceed 2.0 mass%, the cracking sensitivity becomes high. Cu is added to improve the corrosion resistance. If the amount is less than 20 mass%, the effect is small. On the other hand, if it exceeds 40 mass%, the strength at room temperature decreases. Cr is an element useful for corrosion resistance and heat resistance, and is added within a range of 20 to 30 mass% in order to obtain the effect. Al is an element useful for heat resistance, resistance to high-temperature oxidation or deoxidation, and is added in the range of more than 0.8 mass% and not more than 3.5 mass%. In addition, Mo and V are useful for controlling corrosion resistance and crystal grain size, and are added as necessary. Ni is useful for keeping the structure austenite.

Drawing speed: 600 to 900 mm / min When the slab drawing speed is less than 600 mm / min, the residence time in the mold of the slab becomes longer, strong cooling is performed, and the renewal of the molten powder is slowed down. Surface defects such as cracks and bleeding are likely to occur. On the other hand, if the drawing speed exceeds 900 mm / min, the growth speed of the shell cannot catch up within the mold, causing bleeding and breakout. Therefore, the drawing speed is limited to 600 to 900 mm / min.

Molten metal superheat: 5-50 ° C
When the degree of superheat of the molten metal is less than 5 ° C., the molten metal may solidify in the immersion nozzle to cause nozzle clogging, resulting in operation stoppage. On the other hand, if the degree of superheat exceeds 50 ° C., the reaction of the above formula (1) becomes active and the Al ₂ O ₃ pickup becomes intense. If the pick-up amount exceeds 30 mass%, the physical property value deviates from the suitable range of casting. As a result, surface defects such as depletion, vertical cracking, and bleeding are generated. Therefore, the degree of superheat of the molten metal is limited to 5 to 50 ° C.

Al ₂ O ₃ pickup amount in powder: 30 mass% or less As described above, when the Al ₂ O ₃ pickup amount exceeds 30 mass%, the physical property value deviates from the range of casting conditions aimed at by the present invention. As a result, the various surface defects described above occur, the amount of slab grinding increases, and the yield decreases. In the worst case, it will cause a breakout. For this reason, the amount of Al ₂ O ₃ pickup in the powder is limited to 30 mass% or less. Preferably it is 25 mass% or less. In this continuous casting, exothermic powder may be added at the very beginning of casting to help melting. The Al ₂ O ₃ pickup amount can be reduced to 30 mass% or less by setting the basicity of the powder to 0.5 to 1.0.

  Ni-base alloy melts having the component compositions shown in Table 1a and Table 2a were melted and cast with a continuous casting machine using the continuous casting powder shown in this table. For melting, raw materials such as iron scrap, pure nickel, ferrochrome, and stainless steel scrap are melted in an electric furnace and refined using one or both of AOD and VOD, and the predetermined components shown in Table 1a and Table 2a are used. did. The melted alloy types are NCF601 and NW5500, the former are shown in Table 1a and Table 1b, and the latter are shown in Table 2a and Table 2b.

The molten alloy component, powder component, and powder physical properties were evaluated by the following methods.
(1) Molten alloy component: Quantitative analysis was performed using a fluorescent X-ray analyzer. The balance of the components shown in Table 1a is Fe and unavoidable impurities, and also contains a small amount of Si, Mn, P and the like.
(2) Powder component: C was determined by a combustion method and other components were quantified by chemical analysis. The total of each component shown in Table 1a and Table 2a is 93.3 to 99.3 mass% because it contains unavoidable impurities such as Fe ₂ O _{3 in} addition to these components.
(3) Viscosity: measured by the rotating cylinder method. That is, the powder was put in an iron crucible and melted in a vertical resistance furnace, and then the viscosity was measured by inserting and rotating an iron rotor.
(4) Solidification temperature: Since the point at which the viscosity value suddenly rises as the temperature is lowered during the viscosity measurement, this inflection point is taken as the solidification temperature.

When the molten metal shown in Table 1a is continuously cast using the powder of the same table, the Al ₂ O ₃ concentration change in the powder, the presence or absence of defects in continuous casting, the surface quality of the obtained slab and the slab yield after grinding The results are summarized in Tables 1b and 2b. Here, each evaluation was performed by the following method.
(1) Change in Al ₂ O ₃ concentration in powder: A sample was taken from the mold and quantitatively analyzed by chemical analysis.
(2) Surface defect: identified by observing the slab after casting.
(3) Slab grinding yield: Measured from weight change before and after grinding.

(A) NCF601 alloy As shown in Table 1b, the change in the Al ₂ O ₃ concentration in the powder was 30 mass% or less, and in Examples 1 to 5 of the present invention, continuous casting could be performed without any trouble. Also, the obtained slab did not generate any surface defects, and the slab grinding yield was a good result of 94.7% or more. In contrast, Comparative Example No. 6-12, since any of powder components, powder physical properties and casting conditions are outside the limits of the present invention, troubles such as breakout and operation stoppage due to nozzle clogging occur in continuous casting, or Even when it was completely cast, surface defects such as vertical cracks, bleeding, and depletion were caused. Since surface defects occurred, the slab grinding yield was less than 90% even after complete casting, leading to an increase in manufacturing costs.

That is, Comparative Example No. In No. 6, since the concentrations of CaO, Al ₂ O ₃ , and F were outside the appropriate range, the basicity was high and the coagulation temperature was also high. As a result, the amount of molten powder flowing between the solidified shell and the mold decreased, and surface defects such as depletion and bleeding occurred. No. In No. 7, the concentrations of CaO, Al ₂ O ₃ and F were out of the range, and the viscosity and the solidification temperature were increased. As a result, the amount of molten powder flowing between the solidified shell and the mold was reduced, causing a breakout. No. In No. 8, since C as an aggregate was too high, the melting rate was too slow, the inflow could not catch up, and the basicity was low and the solidification temperature was low. As a result, the powder film became glassy, and surface defects such as depletion and bleeding were generated. No. 9, no. In No. 10, since the powder component was not suitable, the basicity was high, and the coagulation temperature was high, surface defects occurred. No. For No. 11, a suitable powder was used, but because the degree of superheated molten metal was too low, nozzle clogging occurred and casting stopped. No. No. 12 used an appropriate powder composition, but the degree of superheating of the melt was high, the growth of the solidified shell was not sufficient, and a breakout occurred.

(B) NW5500 alloy As shown in Table 2b, the change in the Al ₂ O ₃ concentration in the powder is 30 mass% or less, and in Examples 13 to 17 of the present invention, the change in the Al ₂ O ₃ concentration in the powder is small. Continuous casting was possible without any trouble. Further, the obtained slab did not generate any surface defects, and the slab grinding yield was 90% or more and showed a good result. In contrast, Comparative Example No. In Nos. 18 to 24, any of powder components, powder physical properties, and casting conditions is out of the limit range of the present invention. Therefore, troubles such as breakout and operation stoppage due to nozzle clogging occur in continuous casting, or completion. Casting resulted in surface defects such as vertical cracks, bleeding, and depression. Since surface defects occurred, the slab grinding yield was less than 90% even after complete casting, leading to an increase in manufacturing costs.

That is, Comparative Example No. No. 18 had a high basicity and a high solidification temperature because the concentrations of CaO, Al ₂ O ₃ and F were out of the proper range. As a result, the amount of molten powder flowing between the solidified shell and the mold was reduced, causing a breakout. No. In No. 19, the concentrations of CaO, Al ₂ O ₃ and F were out of the range, the viscosity and the solidification temperature were high, and the pickup amount of Al ₂ O ₃ exceeded 30 mass%. As a result, the amount of molten powder flowing between the solidified shell and the mold was reduced, causing a breakout. No. In No. 20, since C as an aggregate was too high, the melting rate was too slow, the inflow could not catch up, and the basicity was low and the solidification temperature was low. As a result, the powder film became glassy, and surface defects such as depletion, vertical cracking, and bleeding occurred. No. 21, no. No. 22 had surface defects because the powder component was not suitable, the basicity was high, and the coagulation temperature was high. No. For No. 23, an appropriate powder was used, but since the degree of superheating of the melt was too low, nozzle clogging occurred and casting was stopped. No. For No. 24, an appropriate powder composition was used, but the degree of superheating of the molten metal was high, the growth of the solidified shell was not sufficient, and a breakout occurred.

  The present invention relates to a Ni-based alloy, and is particularly useful for the production of an Al-containing Ni-based alloy that is suitably used in the water-soluble and marine fields where high corrosion resistance is required or in the field of furnace materials where heat resistance is required. Technology. This technique can also be applied to the stainless steel continuous casting technique used in the field of heat resistance.

Claims (6)

Al: Beyond 0.8 mass% is used in the continuous casting of a Ni-based alloy containing less 3.5 mass% a powder, this _{powder, CaO: 20~30mass%, SiO 2} : 30~40mass%, Na 2 _{O: 1~10mass%, Al 2 O} 3: 0.5~5mass%, F: 10~15mass%, MgO: 0.1~8mass%, MnO: 0.5~5mass%, BaO: 4~10mass% , Li ₂ O: 4 to 10 mass%, C: 0.5 to 3 mass%, and the basicity is 0.5 <CaO / SiO ₂ <1.0, and the viscosity at 1300 ° C. A characteristic of 0.4 to 2 poise and a solidification temperature of 850 to 1100 ° C., and further, a crystal phase is crystallized on the side in contact with the mold when flowing between the mold and the solidified shell. Continuous casting powder for Al-containing Ni base alloy, comprising. 2. The continuous casting powder for an Al-containing Ni-based alloy according to claim 1, wherein the crystal phase has a thickness corresponding to 10 to 80% of the entire powder layer. C ≦ 1.0 mass%, Si ≦ 2.0 mass%, Mn ≦ 2.0 mass%, Cu: 20 to 40 mass%, Al: more than 0.8 mass% and 3.5 mass% or less, Fe ≦ 3.0 mass%, A continuous casting method for an Al-containing Ni-based alloy, wherein the continuous casting powder according to claim 1 is used when continuously casting a molten alloy consisting of Ni and inevitable impurities. C ≦ 1.0 mass%, Si ≦ 2.0 mass%, Mn ≦ 2.0 mass%, Cr: 20 to 30 mass%, Al: more than 0.8 mass% and 3.5 mass% or less, the balance being Ni and inevitable impurities A continuous casting method for an Al-containing Ni-based alloy, wherein the continuous casting powder according to claim 1 is used in continuously casting a molten alloy comprising: 5. The Al-containing Ni-based alloy according to claim 3, wherein the continuous casting is performed under conditions where the superheat degree of the molten alloy is 5 to 50 ° C. and the drawing speed is 600 to 900 mm / min. Continuous casting method. The powder layer formed between the mold and the solidified shell is cast so as to produce a crystal phase having a thickness corresponding to 10 to 80% of the total thickness on the mold side. The continuous casting method of the Al-containing Ni-based alloy described in 1.