JPH03236434A - Nickel-base alloy in which each content of sulfur, oxygen and nitrogen extremely low - Google Patents

Abstract

PURPOSE:To manufacture a high purity Ni-base alloy in which the content of impurities such as O, N and S is extremely low by adding Al and flux to an Ni-base alloy including impurities in a vessel made of CaO-MgO series basic refractories in a nonoxidizing atmosphere or in vacuum and executing refining. CONSTITUTION:An Ni-base alloy essentially consisting of Ni and contg. Fe, Co, etc., is charged to a crucible, a melting furnace or the like made of basic refractories having a compsn. constituted of, by weight, 15 to 75% Mg and 15 to 85% CaO and is melted in vacuum or in an atmosphere of an inert gas such as Ar, He and N. This molten Ni-base alloy is mixed with Al and flux such as the oxides, halides and carbonates of alkali metals and alkaline earth metals and is subjected to deoxidizing, desulfurizing and denitriding treatment. The Ni-base alloy contg., by weight, 0.005 to 7.0% Al, 0.005 to 7.0% Si, 0.0001 to 0.005% Mg, 0.0001 to 0.005% Ca, 0.0001 to 0.002% O, 0.0001 to 0.002% S and 0.0005 to 0.003% N and in which the content of impurities such as O, N and S is low can be manufactured.

Description

[Detailed description of the invention]

(Industrial Application Field) More specifically, the present invention is directed to a high-purity nickel-based alloy that contains nickel (Ni) as a main component, and that the content of each of sulfur, oxygen, and nitrogen is 0.002 to 0. .0
001% by weight, sulfur 0.002-0.0001% by weight,
The present invention relates to a method for producing a nickel-based alloy with extremely low nitrogen content of 0.003 to 0.0005% by weight. (Prior Art) As is already known, many nickel-based alloys have excellent mechanical properties, heat resistance, and corrosion resistance. However, if the residual oxygen and residual sulfur are large, the processability will deteriorate, so it is important to sufficiently reduce the residual oxygen and residual sulfur. It is generally known that CaO-based refractories are stable even at high temperatures and are used for melting various highly reactive alloys. It is also known that when aluminium or aluminum alloy is added to the molten metal in a container lined with this CaO-based refractory, the CaO is reduced by AN to produce Ca, and deoxidation and desulfurization reactions progress. ing. That is, in each of Tokuko Sho 54 (1979) No. 849, Tokoku No. 54 (1979) -24688, and Tokko No. 60 (1985) -25486, Ca
○ Molten steel in which Al or its alloy is added to molten steel in a vacuum or argon gas atmosphere using a melting furnace backed by a highly basic refractory with a content of 40% or more, a lime crucible, or a lime-lined ladle. Deoxidization and desulfurization methods are described. The gist of this method is to reduce CaO in the bulk material by adding Af, and remove sulfur and oxygen in the molten steel using Ca, which is a reduction product. Furthermore, U.S. Pat. No. 4,484,946 discloses that when the melting furnace or crucible backed with the basic refractory is repeatedly used in the method, calcium oxysulfide is formed on the wall of the melting furnace or crucible. accumulates and reduces the rate of deoxidation and desulfurization, therefore flux is added to the molten steel together with additives such as 142, thereby preventing the accumulation of said compounds on the walls of the lime crucible melting furnace or lime crucible. It is stated that (Problems to be Solved by the Invention) According to the above-mentioned conventional method, the sulfur content of molten steel is reduced to approximately 0.00%.
4% by weight, oxygen can be reduced to 0.002% by weight. However, in the field of alloy refining, there is a desire for a refining technology with higher desulfurization and deoxidizing abilities. (Means for Solving the Problems) The object of the present invention is to solve the problems by:
It is an object of the present invention to provide a highly pure nickel-based alloy by improving the ability to produce a nickel-based alloy with lower contents of sulfur, oxygen, and nitrogen. The present invention has aluminum 0.005 to 7.0% and silicon 0.
．． 005-7.0%, magnesium 0.0001-0.
005%, calcium 0.0001-0.005%, oxygen 0.0001-0.002%, sulfur 0.0001-0
．． It is characterized by a nickel-based alloy containing less than 0.002%, nitrogen o, and 0.003%. Describing the method for producing the nickel-based alloy of this invention,
The nickel-based alloy of this invention contains 15 to 75% by weight of Mg.
a lime crucible consisting of or backed by a basic refractory containing O and 15 to 85% by weight of CaO;
Substantially Fe
, Co, and Ni.
a step of melting an alloy from the main components of seeds, and adding aluminum or an aluminum alloy to the molten alloy under a non-oxidizing atmosphere such as argon gas, nitrogen gas or helium gas or under vacuum, The content of oxygen, sulfur, and nitrogen can be reduced by a manufacturing method consisting of a step of deoxidizing, desulfurizing, and denitrifying, and a step of forming an ingot from the deoxidized, desulfurized, and denitrified molten alloy. A nickel-based alloy with extremely low Further, the nickel-based alloy of the present invention can be used in a crucible made from a basic refractory containing 15 to 75% by weight of MgO and 15 to 85% by weight of CaO, or in a crucible supported by the above-mentioned refractory (dolomite). , crucible furnace, melting furnace, smelting furnace (VOD,
a step of melting an alloy made of at least one main component selected from the group consisting of nickel in a container such as AOD) or a converter or a ladle, and supplying argon gas, nitrogen gas to the molten alloy; or a step of adding first and second additives in an atmosphere such as helium gas or under vacuum to perform deoxidation, desulfurization, and denitrification (the first additive is aluminum or and the second additive is selected from the group consisting of boron, alkali metals, and alkaline earth metals) and the thus deoxidized, desulfurized, and denitrified molten alloy is agglomerated. A nickel-based alloy with extremely low contents of oxygen, sulfur, and nitrogen can be obtained by the manufacturing method comprising the steps of: Other methods for producing the nickel-based alloy of the present invention include
Crucibles, crucible furnaces, melting furnaces, smelting furnaces (VOD, AOD) consisting of basic refractories containing 75% by weight MgO and 15-85% by weight CaO or backed by said refractories (dolomite) ) or in a container such as a converter or ladle, and the molten alloy is exposed to a non-oxidizing atmosphere such as argon gas, nitrogen gas or helium gas, or in a vacuum. Below,
5% of the weight of Affi or A42 alloy and said molten alloy
A process of deoxidizing, desulfurizing, and denitrifying by adding the following fluxes (the fluxes are made from oxides, halides, carbides, and carbonates of alkali metals and alkaline earth metals, and oxides of aluminum). Oxygen, A nickel-based alloy with extremely low sulfur and nitrogen contents can be obtained.The nickel-based alloy of the present invention can be obtained from a basic refractory containing 15 to 75% by weight of MgO and 15 to 85% by weight of CaO. melting the Ni-based alloy in the refractory or refractory-backed container; and subjecting the molten alloy to first and second Adding at least one additive and a flux of 5% or less of the weight of the molten alloy to perform desulfurization, deoxidation, and denitrification (the first additive is Af or A
f gold alloy, the second additive is selected from B, alkali metals and alkaline earth metals, and the flux is an alkali metal and alkaline earth metal or rare earth metal oxide, halide, carbide, and It contains at least one component selected from the group consisting of carbonates and aluminum oxides. ) and the step of ingot-forming the molten alloy thus desulfurized, deoxidized, and denitrified, a nickel-based alloy with extremely low sulfur, oxygen, and nitrogen contents can be obtained. . In addition, the nickel-based alloy of the present invention can be prepared by using 1
5-75% by weight MgO and 15-85% by weight CaO
A step of melting and injecting an alloy containing Ni as a main component into a container that is protected from basic refractories containing a basic refractory or a container that is backed by the refractory, and a step of injecting the molten alloy into a non-oxidizing atmosphere or A step of adding /l or A1 alloy under vacuum to perform desulfurization, deoxidation, and denitrification, and a step of forming the molten alloy thus desulfurized, deoxidized, and denitrified into an ingot. A manufacturing method comprising the following steps results in a nickel-based alloy having extremely low sulfur, oxygen, and nitrogen contents. In addition to the above, the nickel-based alloy of the present invention can contain N1 in a container made of a basic refractory containing 15 to 75% by weight of MgO and 15 to 85% by weight of CaO or in a container supported by the refractory. A step of charging a molten alloy as a main component, and under a non-oxidizing atmosphere or vacuum to the molten alloy,
Adding at least one kind of first and second additives to perform desulfurization, deoxidation, and denitrification (the first additive is Af or A1 alloy, and the second additive is , B, alkali metals, and alkaline earth metals);
By the manufacturing method comprising the steps of desulfurizing, deoxidizing, and ingot-forming the denitrified molten alloy, sulfur, oxygen,
A nickel-based alloy with extremely low contents of nickel and nitrogen can be obtained. In a preferred embodiment for producing the nickel-based alloy of the present invention, the container includes a crucible, a crucible furnace, a melting furnace, a refining furnace (VOD vacuum oxydiene degasser, an AOD air oxydiene degasser), a converter, etc. Or a ladle. Similarly, the non-oxidizing atmosphere is an atmosphere of argon gas, nitrogen gas, or helium gas. Similarly, the basic refractory contains 20 to 60% by weight of Mg.
O and at least 40% by weight of CaO. The above additives are Af-Ca clad wire, ΔN-3i
Composite additives of the 11 series (but not alloyed cladding materials) such as cladding wire can also be used. Flux can be added to the above additives in combination, if necessary. For this flank ashes collection, it is possible to use at least one flux selected from the group consisting of alkalis, alkaline earth metal oxides, silicides, carbonates, and halides thereof, or a flux containing aluminum oxide. The nickel-based alloy of the present invention produced by the above method is
Residual sulfur not more than 0.0015% by weight, 0.002% by weight
It contains residual oxygen of no more than 0.003% by weight and residual nitrogen of no more than 0.003% by weight. Similarly, the nickel-based alloy is added in an amount of 0.005 to 7% by weight in the final molten metal after deoxidizing, desulfurizing, and denitrifying the molten alloy.
residual Affi, 0.0005-0.005 wt% residual Mg and 0.0001-0.005 wt% residual Ca
Contains. Similarly, the nickel-based alloy further includes at least one or two or more selected from the group consisting of B, alkali metals, and alkaline earth metals excluding Mg and Ca.
Contains ~10% by weight. (Function) The above-mentioned Japanese Unexamined Patent Publication No. 1979-58010 discloses a step of melting steel in a melting furnace or ladle supported by a basic refractory containing at least 60% by weight of CaO; By adding An to this molten steel under an argon gas atmosphere or vacuum, the above-mentioned backing reduces CaO in the refractory to generate Ca, and this Cal deoxidizes, desulfurizes, and deoxidizes the molten steel. At the same time as nitrification, 0.0% of A1 is added to the molten steel.
005-0.06% by weight, Ca 0.001-0.03
% by weight, and the oxygen content is 0.003% by weight or less, the sulfur content is 0.010% by weight or less, and the nitrogen content is 0.0% by weight.
A method for producing clean steel with low oxygen, sulfur and nitrogen contents is described, comprising reducing the content to below 10% by weight. However, the inventors further experimented with the above method and found that
After repeated studies, we found that in the furnace wall of a crucible or furnace where MgO and CaO coexist, when AE or Af alloy is added, Mg is also produced in addition to Ca in the molten steel, resulting in a strong layer. It has been found that deoxidation and desulfurization are carried out. The present invention is based on this finding. In one embodiment of the method of making the nickel-based alloy of the present invention, 15-75% by weight MgO and 15-85% by weight MgO
a crucible made of a basic refractory containing % by weight of CaO;
A container such as a crucible furnace, converter, or ladle is used in which the iron-based alloy, cobalt-based alloy, or nickel-based alloy is melted. The molten alloy in this vessel is exposed to AI! under a non-oxidizing atmosphere such as argon, nitrogen, or helium gas or under vacuum. , and A/2 alloy. In another embodiment, the alloy is previously melted in a commonly used furnace and the molten alloy is charged into the vessel. Similarly, Af or A1 alloy is added to the molten alloy in this container. In another embodiment, the container is replaced by a container backed by the refractory, such as a crucible furnace, converter, or melting pot. In each of the above embodiments, the additive A2 added to the molten alloy in the container directly combines with oxygen in the molten alloy in vacuum or a non-oxidizing atmosphere to generate Ahol, Deoxidation is performed, but the other part of A/2 reacts with MgO and CaO on the surface of the refractory in a vacuum or non-oxidizing atmosphere to form 3Ca○+2 A 1→3 Ca +Ab(h ”'
・・・'・・'(1) 3Mg○+2 A E -3M
g +AlzO:+---(2), Mg, Ca
and AIZ(h) are produced. In particular, the reaction (2) is performed in vacuum or in a non-oxidizing atmosphere with CaO
The presence of an appropriate amount (15-85%) facilitates progression to the right side. This reaction is considered to be a complex reaction as shown below. 3 M g○+Ca O+ 2 A I! , -3M g
O+CaAlzO4...(3) This CaO・A1□
Calcium aluminate containing 03 as a main component has a high desulfurization ability, and desulfurization of the molten alloy progresses due to this. Also Ti, C
The following reaction also occurs due to the presence of e etc.Ca○+Ti-+Ca+Ti○ ・・・・・・・・・・・・
・・・・・・・・・(4) MgO+T i-+Mg+T
i O・・・・・・・・・・・・・・・・・・・・・(5)3
Ca○12 Ce →3 Ca +CezOi ・+
-...(6) 3MgO+2Ce→3Mg+cezOz
+・++−c7) In addition to the above reactions, oxygen in the molten metal,
Sulfur and nitrogen are first changed to 2Af+30→Ah(h...
・・・・・・(8) Af+N-+AfN ・・・・・・
・・・・・・・・・・・・(9) Ti+O−+TiO・
・・・・・・・・・・・・・・・・・・00) Ti+N→
TiN・・・・・・・・・・・・・・・(11)
Ti+S-+TiS ・・・・・・・・・・・・
(12) 2Ce+30→CezO:+・・・・・・・・・
・・・・・・・・・(13) 2 Ce + 3 S −+C
ezS:+ ++ (14)Ce+N→CeN
・・・・・・・・・・・・・・・(15) In addition, the sulfur, oxygen, and nitrogen components remaining in the molten metal are caused by the Mg and Ca reduced and precipitated in the molten metal as described above, respectively, as shown in the following formula. As a result, extremely clean molten metal can be obtained. Ca+S->CaS・・・・・・・・・・・・・・・
・・・・・・(16) Ca+○→CaO・・・・・・・・・
・・・・・・・・・・・・(17)3 Ca +2
N-+CaJz・・・・・・・・・・・・・・・・・・
(1 day) Mg+S-+MgS ・・・・・・・・・・・・
・・・・・・・・・(19)Mg+O−)MgO・・・・
・・・・・・・・・・・・・・・(20) 3Mg+2N→
Mg3Nz ・・・・・・・・・・・・・・・・・・
(21) In this way, deoxidation is carried out by Af, and active Mg and Ca are generated by the reducing action of A1.
Deoxidation and desulfurization are performed using calcium aldanate (3CaO・A1203). Since these reactions proceed extremely rapidly, desulfurization and deoxidation are almost completed within a few minutes after AI is added to the molten metal. Further, as time passes, the amount of N in the molten metal gradually decreases. This is because N also leaves the molten metal as Ca, Mg, etc. evaporate (boil). This denitrification rate increases significantly as deoxidation and desulfurization progress under non-oxidizing gas (for example, argon gas atmosphere) or vacuum. In the present invention, a container such as a converter, a melting furnace, a crucible, or a ladle contains Mg015-75% by weight and Ca015-75% by weight.
The reason why the refractory is composed of or supported by a composition containing 85% by weight will be explained. Figures 1 and 2 show M in CaO-MgO refractory materials.
The desulfurization properties are shown in experiments in which 0.5% Al was added to molten iron using crucibles with various gO contents. In Fig. 2, j2og (S) t / (s) o is the desulfurization capacity, (S) t is the amount of residual sulfur after t minutes, and [
S) o indicates the initial sulfur amount. As shown in the figure, MgO is 1
It is clearly seen that when the content is 5 to 70%, particularly 20 to 60%, an extremely strong desulfurization reaction takes place. In addition, Fig. 2 also shows the analytical value of residual/l (Af weight %), and it is seen that the amount of Al1 decreases with the passage of time after addition, which indicates that the aforementioned reaction between MgO and Al progress is confirmed. CaO is essential as the remaining component other than MgO. CaO itself is reduced by Aj2 to produce Ca, and coexists with MgO to produce Mg.
Promotes O reduction reaction. A preferable content of CaO is at least 1% of the entire refractory.
5% or more, especially 40 to 80% by weight. When the CaO content is lower than 40%, C in the refractory
Since aO is strongly bonded to other oxides, the activity of CaO is low and it is difficult to be reduced by 1,11. In contrast, CaO in refractories with at least 40% CaO
has high activity and is well reduced by /l. Moreover, refractories containing at least 40% of CaO are made of Ah(
It easily reacts with oxides such as h and 5i02, and therefore absorbs oxides in the molten metal, greatly reducing the amount of oxide inclusions. Furthermore, since such refractories have high stability against C, Ti, Zr, etc., it is possible to melt alloys at high temperatures. In carrying out the present invention, at least one member selected from the group consisting of B, alkali metals, and alkaline earth metals may be added together with A1 to the molten metal. Examples of the alkali metal include Na, and Li. For example, Ca, B, NaK, and Li added to the molten metal are C
aO, B20i, NazO, kzOLtzO,
In refractory walls, these oxides are Al2O:1-Ca
O-B203 Al2O3-CaO-B2O2NazOAl, 03-C
Forming a low melting point composition such as aO-B203 kzO,
Increases deoxidation and desulfurization rate. That is, oxides such as Ca, B, Na, and Li combine with calcium aluminate compositions such as CaO and MgO already formed on the furnace wall surface to produce a low melting point composition. Because compounds, atoms or their ions (such as S2-) in the molten alloy easily diffuse into this composition,
Deoxidation and desulfurization reactions are accelerated. Also, C a O, Bz (h and alkali metal oxides,
In particular, B, O, and alkali metal oxides, when incorporated into the slag, also lower the melting point of the slag and lower its viscosity. As a result, 3z in the molten alloy
- to increase the diffusion coefficient of ions, other atoms, and compounds to the slag. Therefore, the desulfurization rate increases and the deoxidizing ability is greatly improved. In the nickel-based alloy produced by the above method, residual aluminum and 0.005 to 7% by weight of residual magnesium
0.0005-0.005% by weight residual calcium
It is necessary to add these metals so that 0.0001 to 0.005% by weight of each remains. The reason why the residual amount of Af in the alloy is preferably in the range of 0.005 to 7% by weight is that when the residual amount of A/2 is less than 0.005%, not only is sufficient deoxidation not performed. , Ca is hardly produced. Therefore, the result is that desulfurization, deoxidation, and denitrification by Ca are hardly performed.
This is because the amount of residual calcium in the finished alloy is at least 0.0001%, which is the basis for sufficient desulfurization, deoxidation, and denitrification by Ca. On the other hand, the upper limit is because alloys containing more than 7% aluminum are impractical. If the B residual amount is less than 0.001%, it is too small and the effect of B is small, and if it is more than 10%, the manufactured alloy will be inferior. A particularly preferable residual amount of B is 0.005 to 3%. Al and titanium (Ti), zirconium (Zr)
, niobium (Nb), and rare earths (Li, Cf, etc.), when boron (B), alkali metals, and alkaline earth metals are added to the molten metal, even if they are added in alloy form, It may be added as a single metal, and there are no particular restrictions on the form of its addition. Ti, Zr, Nb and B along with Af
When adding metals, it is possible to add them as single metals, but alkali metals and alkaline earth metals are highly reactive and have problems in handling.
Preferably, it is added in the form of an alloy. In the case of adding a single metal or an alloy together with /l, it can be added in various forms such as a linear body, a rod-shaped body, a block, a powder, or a clad wire. - For example, Af-Ca core material, bonded wire rod, or A with flux added to Al-Ca core material.
An f-Ca clad wire can be used. The Mg and Ca residual amounts of the alloy produced by the method of the present invention are M g300~ippm (0,03~Q,0
(101% by weight), preferably 30-5 ppm (
0,003-0.0005% by weight), Ca200-1p
pm (0.02-0.0001% by weight), preferably 1
00-5 ppm (0.01-0.0005% by weight
) If the residual amount of Mg and Ca is too small, the deoxidation, desulfurization, and denitrification effects will be low, and if it is too large, the alloy will become brittle. In addition, in the present invention, rare earth elements are further added to the molten metal.
It may be added so that it remains in the final product alloy in a range of 200 ppm or less. In a preferred embodiment of the present invention, continuous refining is carried out by repeatedly adding 5% or less of a flux containing at least one of alkali metal and alkaline earth metal oxides, carbonates, halides, carbides, alumina, etc. It is effective if In other words, this effect is due to the fact that when the container is used repeatedly, oxysulfides adhere to the surface of the wall, causing accumulated contamination.
To prevent this, flux can be used to remove contaminants. The present invention will be explained in more detail with reference to the following specific examples. Comparative Example 1 As a starting material, 500 g of electrolytic iron having the composition shown in Table 2 to which FeS had been added in advance to a sulfur content of approximately 0.03% was placed in a Ca○ crucible having the composition shown in Table 1. The crucible was placed in a 50 KHz high frequency melting furnace to melt the material. After melting, 0.4% (by weight) of Af gold alloy was added to the molten material while introducing argon gas into the furnace. After the addition, samples were taken from the molten material by suction at predetermined time intervals, and the contents of oxygen, sulfur, and nitrogen were measured. This deoxidizing ability fog(0)o/

[0]t ([○
]t represents the residual oxygen amount after t minutes, and [O]o represents the initial oxygen amount. ) The desulfurization capacity fog[s]t/[S)o and the changes in nitrogen content over time are shown in FIG. The CaO crucible used was made from - grade reagent CaO, which was crushed into 20 meshes, put into a crucible mold and hardened, and the solidified crucible was heated at about 900°C124.
It was prepared by calcining in an electric resistance furnace for hours. Table 1 Crucible Composition Example 1 Using first-class reagents MgO and CaO as raw materials, a Mg0-CaO crucible with the composition shown in Table 3 was prepared, and the experiment was conducted in the same manner as in Example I except that the crucible was used. I did this. The results are shown in Figure 3 and Table 2. Electrolytic Nikel composition (wt%) As is clear from Figure 3, according to the method of the present invention, a molten metal with low oxygen, sulfur, and nitrogen contents can be quickly obtained. It is recognized that the desulfurization effect is particularly large. The Cab and MgO crucibles used in the above tests were made using pure materials with few impurities, but ordinary SiO2
When a CaO-enriched dolomite brick made by enriching a dolomite brick containing 2.4% CaO was used, the desulfurization effect was significantly reduced. The reason for this is that SiO2 contained as an impurity is Cab,
This is thought to be because Ca and Mg were not generated when Aj2 was added to molten steel because it was stabilized by combining with MgO. Example 2 The amount of Al added was 0.5%, and the MgO content of the crucible material was 1
Comparative example 1 except for various changes from 0% to 70%
An experiment was conducted in the same manner. The results of measuring the desulfurization properties and residual amount of AI2 for samples using crucibles with different compositions are shown in FIGS. 1 and 2. Incidentally, FIG. 2 also shows the measurement results in Comparative Example 1 (using a crucible containing 100% Ca). From these figures 1 and 2, as mentioned above, Mg015
It is recognized that a remarkable desulfurization effect can be obtained in the range of ~70% and Ca015~85%. Thus, the alloy of the present invention produced by the above-mentioned method has a sulfur content of 1/50th (15ppn+ or less, especially 10ppm or less) and an oxygen content of 1/50th or less (7ppm or less) of the initial content.
It can be seen that this is an extremely clean alloy with a nitrogen content of 30 ppm or less, especially 20 ppm or less. As described above, according to the above-mentioned method, extremely strong deoxidation, desulfurization, and denitrification can be performed in the production of the Ni-based alloy of the present invention. It is possible to produce alloys with outstanding properties such as strength, heat resistance, toughness, weldability, and forgeability. Furthermore, according to the method of the present invention, a product with almost no oxide inclusions can be obtained. In the above description of the method for producing the alloy of the present invention, the term "non-oxidizing gas" refers to blowing a non-oxidizing gas such as argon gas, nitrogen gas, or helium gas into the molten metal in an open or closed furnace. This refers to the atmosphere in which the molten metal is treated by, or by forming this gas atmosphere on the surface of the molten metal in a closed furnace so that the surface of the molten metal is covered with such gas. Nickel-based alloys targeted by the present invention contain nickel as a main structure or component, and include mainly heat-resistant and corrosion-resistant alloys, magnetic alloys, and the like. Alloys belonging to this category include Ni-Cu alloy (monel metal), N
i-Cr-Fe alloy (Inconel), Ni-Mo alloy (Hastelloy A B), Ni-Mo-Cr-W alloy (Hastelloy C), Ni-3i alloy (Hastelloy D)
), Ni-Ta alloys, etc. Examples 3 to 8 CaO crucible (Example 3) having the composition shown in Table 4 and Ca
In an O-MgO crucible (Examples 4 to 8), NiS was added in advance to electrolytic Ni having the composition shown in Table 4 so that the sulfur content was 300 ppm (0.03%).
g was charged as a starting material, and the crucible was placed in a high frequency melting furnace at 50 Hz to melt the material. After melting, 0.5% by weight of A42 alloy was added to the molten alloy without introducing argon gas into the furnace. After the addition, samples were taken from the molten alloy by suction at predetermined intervals, and the contents of oxygen, sulfur, and nitrogen were measured. The deoxidizing capacity log (0) t / (0) o (however,

[0] t is the amount of residual oxygen after L minutes, [○] 0 is the initial amount of oxygen), desulfurization capacity log (S:] t / (S)
Figure 4 shows the temporal changes in o and nitrogen content. Fourth
In the figure, 0.5% Al is added, [SO] is 10% Mg○, 30% in a CaO crucible with an initial sulfur content of 300 ppm.
An example using a CaO-MgO crucible to which MgO is added is 150% MgO 160% MgO 170%. The CaO-MgO crucible used was made from general reagents CaO and MgO, which were crushed into 20 meshes, placed in the crucible and compacted well, and the solidified crucible was heated at approximately 900°C for 124 hours. It was produced by calcination in an electric resistance furnace. Table 4 shows the desulfurization rate constant and residual element amount when the desulfurization treatment was performed with the amount of Aj2 added at 0.5% and the MgO content in the lime crucible material varied from 10% to 70%. It is shown that the desulfurization rate constant is large when the crucible material is 30% and 50%. Figure 5 shows Afo, 5% added Ca.
The relationship between the amount of MgO mixed in the O crucible, the achieved desulfurization value, the amount of residual Mg, and the desulfurization rate constant is shown. As shown in Table 5, the molten metal was added to the electrolytic Ni at 300 p
15%M in a CaO crucible to the vulcanized product with sulfur content of pm
g○, 50% MgO170% MgO added Ca0-
Using Mg○ crucible, A420.3% by weight, Ca0.2
0.5% by weight of Af-Ca clad wire consisting of 0.5% by weight
The desulfurization rate constant and the analysis value (ppm) of each element 10 minutes after adding the A1Ca clad material are shown. Here, So... initial sulfur amount S,... parallel sulfur amount t,... time until equilibrium is reached. Figure 5 shows the amount of Mg mixed in CaO, the reached desulfurization value, the desulfurization rate constant, the amount of residual Mg, and the residual Ca@ when 0.5% of AfCa clad material with composition AlO, 3% and Ca 0.2% is added.
Indicates the relationship between As is clear from Figure 5, MgO was added to the CaO crucible for 15~
75% by weight was used, and An-C was added as an additive.
When using a-clad wire, the amount of sulfur reached is 1 pp.
It was confirmed that a cobalt-based alloy with an extremely low sulfur content down to m (0,0001%) could be obtained. Examples 13-15 Molten metal was 22% Cr, 2% Co, 18% Fe, Mo9
Example 13. Hastelloy In Example 14, the ratio of CaO-CaF2-Al2O2 was 6:
Table 6 shows the effect of adding flux when 100 g of 3:1 flux was added, 2 kg was dissolved, and a CaO-50% MgO crucible material was used repeatedly. Example 13 shows that flux was added the first time the crucible material was used repeatedly, and Example 14 showed that flux was added the fifth time the crucible material was used repeatedly.
Example 15 is a case in which the product was used repeatedly up to the fifth time and no flux was added. Table 7 shows the composition of the high purity calcia (CaO) crucible used, and Table 8 shows the composition of the high purity MgO used for mixing in this calcia crucible. Table 8 Composition of high purity MgO used in mixing Table 9 shows the composition of electrolytic nickel used (% by weight). Note: - Analytical value S after dissolution and before addition of 11...300 ppm...adjusted by FeS addition 0
...300 ppm N...40 ppm The analytical values after dissolution and before addition of Al are as follows. S -300ppm (Adjust S amount by adding FeS) ○...300 ppm N...40 ppm Example 16 D B was actually tested using the examples and comparative examples shown in the table below.
T T (Ductile - brittle tr
The results of the measurements will be described below. The raw material used was electrolytic iron, and Comparative Example A was dissolved bone in a CaO crucible, with a composition of O: 8 ppm, S: 5 ppm, Mg<lpp.
m, Ca #10 ppm. Example B has a composition ○ near p
pm, S:lppmXMg”i27ppm,,Ca#1
It is 0 ppm. DBTT was measured by measuring the temperature at which the impact absorption energy value changes using a Charpy type test piece. From the above measurement results, it was found that in the present molten steel (sample B), the composition as claimed in the claims has a very large effect on toughness and malleability. Example 17: - A creep rupture life test was conducted using AIS1316 steel. The chemical compositions of Examples and Comparative Examples are shown in Table 12. Table 13 shows the results of comparing the creep rupture life at 550″C.
mφ, distance between gauges: 30mm, stress value 35kg/mm
It is 2. From this result as well, great effects were recognized within the claimed scope of the composition of the present invention.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the MgO content of the basic refractory of the container, the desulfurization rate constant (K), the amount of sulfur reached, and the amount of residual Mg when 0.5% Af is added. Figure 2 shows the AE
3 is a graph showing changes in residual Aff amount and desulfurization ability over time after addition of 5%. FIG. 3 is a graph showing changes over time in deoxidizing ability, desulfurizing ability, and nitrogen content in the molten alloys according to Examples 1 and 2. FIG. 4 is a characteristic diagram showing changes over time in desulfurization ability when 5% AlO was added in various crucibles with different amounts of MgO in a CaO crucible (comparative example) and a CaO-MgO crucible. Figure 5 shows Al by changing the amount of MgO in the CaO-MgO crucible.
-The amount of sulfur achieved when adding 0.5% of Ca cladding material,
It is a characteristic diagram showing the relationship between the desulfurization rate constant, the amount of residual Mg, and the amount of residual Ca.

Claims (1)

[Claims] 1. Aluminum 0.005-7.0%, Silicon 0.0
05-7.0%, magnesium 0.0001-0.00
5%, calcium 0.0001-0.005%, oxygen 0
．． 0001-0.002%, sulfur 0.0001-0.0
0.02%, nitrogen 0.0005-0.003%.