U.S. patent application number 12/296907 was filed with the patent office on 2009-11-12 for process for production of fe based amorphous alloy.
This patent application is currently assigned to Nippon Steel Corporation. Invention is credited to Takeshi Imai, Yuji Ogawa, Shigekatsu Ozaki.
Application Number | 20090277304 12/296907 |
Document ID | / |
Family ID | 38609566 |
Filed Date | 2009-11-12 |
United States Patent
Application |
20090277304 |
Kind Code |
A1 |
Ogawa; Yuji ; et
al. |
November 12, 2009 |
PROCESS FOR PRODUCTION OF FE BASED AMORPHOUS ALLOY
Abstract
According to exemplary embodiments of the present invention, a
process for production of an amorphous alloy can be provided at low
cost by, e.g., efficiently removing magnetic-property-degrading Al
and Ti when using inexpensive Fe--B or scrap as an amorphous alloy
raw material. An exemplary embodiment of the process for production
of an Fe-based amorphous alloy ribbon can comprise, by mass, e.g.,
2 to 4% of B, 1 to 6% of Si, and a balance of Fe and unavoidable
materials is provided. For example, it can be determined whether
the molten alloy obtained by melting a main raw material has a Ti
concentration or Al concentration of 0.005 mass % or greater: When
such even occurs, iron oxide source having an iron content of 55
mass % or greater can be added thereto to reduce both Ti and Al to
less than 0.005 mass % by oxidative removal. Alternatively, it is
possible to determine whether the main raw material has a
composition whose Ti concentration or Al concentration is 0.005
mass % or greater, and when it does, an iron oxide source having an
iron content of 55 mass % or greater is precharged into a melting
vessel together with the main raw material.
Inventors: |
Ogawa; Yuji; (Tokyo, JP)
; Imai; Takeshi; (Tokyo, JP) ; Ozaki;
Shigekatsu; (Tokyo, JP) |
Correspondence
Address: |
DORSEY & WHITNEY LLP;INTELLECTUAL PROPERTY DEPARTMENT
250 PARK AVENUE
NEW YORK
NY
10177
US
|
Assignee: |
Nippon Steel Corporation
Tokyo
JP
|
Family ID: |
38609566 |
Appl. No.: |
12/296907 |
Filed: |
April 6, 2007 |
PCT Filed: |
April 6, 2007 |
PCT NO: |
PCT/JP2007/058121 |
371 Date: |
October 10, 2008 |
Current U.S.
Class: |
75/526 |
Current CPC
Class: |
C22C 45/02 20130101;
C21C 5/562 20130101; C22C 2200/02 20130101; C21C 7/076 20130101;
Y02P 10/216 20151101; H01F 1/15308 20130101; Y02P 10/242 20151101;
C22C 1/00 20130101; C22C 33/003 20130101; C21D 7/04 20130101; Y02P
10/20 20151101 |
Class at
Publication: |
75/526 |
International
Class: |
C21C 7/00 20060101
C21C007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 11, 2006 |
JP |
2006-108422 |
Claims
1-4. (canceled)
5. A process for producing an Fe-based amorphous alloy which
comprises, by mass, about 2 to 4% of B, about 1 to 6% of Si, and a
balance of Fe and unavoidable materials, the process comprising:
determining whether an iron melt obtained by melting a main raw
material has a Ti concentration or an Al concentration of at least
about 0.005 mass %; and when such determination yields a positive
result, adding an iron oxide source having an iron content of at
least about 55 mass % to the molten alloy to reduce Ti and Al to
less than about 0.005 mass % using an oxidative removal
procedure.
6. The process according to claim 5, wherein the Fe-based amorphous
alloy further comprises, by mass, at least one of about 0.001 to 3%
of C or about 0.008 to 0.15% of P.
7. The process according to claim 5, wherein, by mass, Fe is
partially replaced by at least one of Co plus Ni of at most about
20% of Fe content and Cr of at most about 6% of Fe content.
8. A process for producing an Fe-based amorphous alloy which
comprises, by mass, about 2 to 4% of B, about 1 to 6% of Si, and a
balance of Fe and unavoidable materials, the process comprising:
determining whether a main raw material has a composition which
includes a Ti concentration or an Al concentration of at least
about 0.005 mass %; and when such determination yields a positive
result, precharging an iron oxide source having an iron content of
at least about 55 mass % into a melting vessel with the main raw
material.
9. The process according to claim 8, wherein the Fe-based amorphous
alloy Fe-based amorphous alloy further comprises, by mass, at least
one of about 0.001 to 3% of C or about 0.008 to 0.15% of P.
10. The process according to claim 8, wherein, by mass, Fe is
partially replaced by at least one of Co plus Ni of at most about
20% of Fe content and Cr of at most about 6% of Fe content.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a national stage application of PCT
Application No. PCT/JP2007/058121 which was filed on Apr. 6, 2007,
and published on Oct. 25, 2007 as International Publication No. WO
2007/119806 (the "International Application"). This application
claims priority from the International Application pursuant to 35
U.S.C. .sctn. 365, and from Japanese Patent Application No.
2006-108422 filed Apr. 11, 2006, under 35 U.S.C. .sctn. 119. The
disclosures of the above-referenced applications are incorporated
herein by reference in their entities.
FIELD OF THE INVENTION
[0002] The present invention relates to a process for production of
an Fe-based amorphous alloy at a low cost.
BACKGROUND INFORMATION
[0003] Amorphous alloy ribbons whose base component system is
Fe--B--Si have excellent properties as electromagnetic materials.
When used as an iron core material in an electric power
transformer, such an amorphous alloy ribbon can lower core loss to
about 1/3 that when using conventional grain-oriented Si-steel
sheet. However, the implementation of the mass production of
Fe--B--Si amorphous alloy ribbons has been slow.
[0004] One of the main reasons for this may be that the cost of the
amorphous alloy ribbons is much higher than that of Si-steel sheet.
Most of the cost is accounted for by the Fe--B or other main raw
material.
[0005] A method for inexpensive production of amorphous alloy is
described in Japanese Patent Publication (A) No. S58-77509 which
provides a process for smelting reduction of boron oxide or boric
acid and iron oxide using a carbon-based solid reducing agent such
as coke. However, owing to the use of a carbon reducing agent, this
method has a problem in that when it is attempted to directly
produce the amorphous alloy to optimum B and Si contents for
obtaining a steel with good electromagnetic properties, the C
content comes to exceed the optimum range.
[0006] For overcoming this problem, Japanese Patent Publication (A)
No. S59-38353 describes a method of once producing a matrix alloy
with high B and Si contents so that a C content in the optimum
range can be obtained and thereafter diluting the B and Si with a
separately produced molten steel. However, since the product is
obtained via the matrix alloy with a high B content, this method
shortens the service life of the melting furnace refractory and
increases raw material consumption per unit product because B
reduction yield is lowered. Japanese Patent Publication (A) No.
S62-287040 further describes a method for overcoming these problems
by adjusting the composition of the matrix alloy to a somewhat low
B content and high Si content.
[0007] However, the above-described methods all reduce B, Si and Fe
oxides with carbon. Such methods can thus be flawed in the point of
requiring great reductive energy and also in the point that they
increase refractory cost tremendously because the reductive energy
is obtained by using a hot air blast to burn the carbon, thus
producing a high temperature that forms a molten slag made of B, Si
and Fe oxides that readily causes fusion damage of the
refractory.
[0008] Other general methods for producing Fe--B as a B raw
material can include methods that perform refining by the aluminum
thermite reaction or the electric furnace method. However, the
electric furnace method consumes significant amount of electric
power, likely resulting in high power costs and increasing the cost
of amorphous alloy production. Although the aluminum thermite
method is low in production cost, the resulting Fe--B includes Al
and Ti, and an amorphous alloy produced using the Fe--B is
therefore increased in Ti concentration and Al concentration. As
increased Ti and Al concentration is known to degrade magnetic
properties, Fe--B produced by the aluminum thermite reaction cannot
be used to produce amorphous alloys until cheap removal of Ti and
Al becomes possible.
[0009] Although it is also possible to lower production cost by
using scrap Si-steel sheet or the like as the starting material
containing Fe and Si, such scrap is difficult to use for amorphous
alloy because the Al contamination of the scrap similarly increases
the Al concentration of the amorphous alloy.
[0010] Accordingly, there may be a need to address and/or overcome
at least some of the deficiencies described herein above.
SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION
[0011] In view of the previously-described problems, [0013]
Exemplary embodiments of the present invention can be provided with
an exemplary process for production of an Fe-based amorphous alloy
ribbon at low cost by efficiently removing
magnetic-property-degrading Al and Ti when using inexpensive Fe--B
or scrap as an amorphous alloy raw material.
[0012] An exemplary embodiment of the present invention for
overcoming such problems can provide a process for production of an
Fe-based amorphous alloy comprising, by mass, about 2 to 4% of B,
about 1 to 6% of Si, and a balance of Fe and unavoidable materials.
Using such exemplary process, it is possible to determine whether a
molten alloy obtained by melting a main raw material has a Ti
concentration or Al concentration of about 0.005 mass % or greater.
When it does, it is possible to add thereto an iron oxide source
having an iron content of about 55 mass % or greater to reduce both
Ti and Al to less than about 0.005 mass % by oxidative removal.
[0013] According to another exemplary embodiment of the present
invention, a process can be provided for a production of an
Fe-based amorphous alloy comprising, by mass, about 2 to 4% of B,
about 1 to 6% of Si, and a balance of Fe and unavoidable materials.
This exemplary process can determine whether a main raw material
has a composition whose Ti concentration or Al concentration is
0.005 mass % or greater. When such result is obtained, it is
possible to precharge an iron oxide source having an iron content
of about 55 mass % or greater into a melting vessel together with
the main raw material.
[0014] According to yet another exemplary embodiment of the present
invention, the Fe-based amorphous alloy can further include, by
mass, one or both of about 0.001 to 3% of C and/or about 0.008 to
0.15% of P. Further, Fe can be partially replaced by at least one
of Co plus Ni of at most about 20% of Fe content and Cr of not
greater than about 6% of Fe content.
[0015] These and other objects, features and advantages of the
present invention will become apparent upon reading the following
detailed description of embodiments of the invention, when taken in
conjunction with the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Further objects, features and advantages of the invention
will become apparent from the following detailed description taken
in conjunction with the accompanying figure showing illustrative
embodiment(s), result(s) and/or feature(s) of the exemplary
embodiment(s) of the present invention, in which:
[0017] FIG. 1 is a diagram showing time-course changes in molten
alloy Ti concentration when iron oxide sources are added to molten
alloy of an amorphous alloy raw material; and
[0018] FIG. 2 is a diagram showing time-course changes in molten
alloy Al concentration when iron oxide sources are added to molten
alloy of an amorphous alloy raw material.
[0019] Throughout the figures, the same reference numerals and
characters, unless otherwise stated, are used to denote like
features, elements, components or portions of the illustrated
embodiments. Moreover, while the present invention will now be
described in detail with reference to the figures, it is done so in
connection with the illustrative embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0020] According to an exemplary embodiment of the present
invention, using a small melting furnace, it can be determined that
addition of iron oxide to an Fe-based amorphous alloy raw material
during melting provide an efficient oxidative removal of Ti and Al.
Ti and Al are oxidized preferentially relative to B or Si
constituting the main components of the amorphous alloy and can
therefore be oxidatively removed without significantly reducing B
or Si yield.
[0021] In one exemplary embodiment of the present invention, a main
raw material mixed with the required B and Si components can be
melted in a melting furnace. When a molten alloy has been formed,
Ti and Al can be oxidatively removed by adding an iron oxide source
containing at least 55 mass % of iron.
[0022] In a small-scale experiment, an amorphous alloy raw material
containing B: about 3.2 mass % and Si: about 1.8 mass % was
produced in a melting furnace, the temperature of the molten alloy
was raised to about 1,500.degree. C., and an iron oxide source was
added at the rate of, by mass, about 50 kg per ton of molten alloy.
The experiment was conducted using various iron oxide sources. A
graph of certain results of the time-course changes in the
concentrations of Ti and Al in the molten alloy is provided in FIG.
1. In the case of all iron oxide sources having an iron content of
at least 55%, Ti and Al were reduced to less than about 0.005 mass
%, a level at which no effect on magnetic properties is
observed.
[0023] However, the speed of Ti and Al oxidative removal decreased
in proportion as the iron oxide source was lower in iron content
and higher in content of gangue constituents other than iron oxide.
On the other hand, when steelmaking dust of an iron concentration
of less than about 55% was used as the iron oxide source, the Ti
and Al oxidative removal speed was slow and Ti was not reduced to
less than about 0.005 mass %. A production cost analysis was
carried out taking into account the amount of added iron oxide
source required, refining time, slag treatment expense owing to
increase in generated slag volume from gangue and the like, and
other factors. The results showed that the effect can be small
unless the iron concentration is about 55% or greater.
[0024] The holding time after iron oxide source refining can
depends on the amount of iron oxide source used, and may be
preferably about 15 min or longer.
[0025] In another exemplary embodiment of the present invention, an
iron oxide source containing at least about 55 mass % of iron can
be precharged into a melting furnace together with a main raw
material prepared to include the required B and Si contents.
Thereafter, melting may be conducted to produce an amorphous alloy
raw material. When the dust collection capability of the melting
furnace is low, this exemplary embodiment can be preferably adopted
because the prior-described exemplary embodiment in which the iron
oxide source can be added after producing the molten alloy may
generate dust at the time of the addition.
[0026] Table 1 shows exemplary Ti and Al concentrations of the
molten alloy when, in the small-scale experiment discussed earlier,
the various iron oxide sources were precharged into the melting
furnace at the rate of, by mass, about 50 kg per ton of molten
alloy and melted together with the main raw material. The
temperature at 10 min after meltdown was about 1,370 to
1,380.degree. C. If Ti and Al had not been removed, their
concentrations would have stayed the same as the initial values in
FIG. 1. However, e.g., in every case where an iron oxide source
having an iron concentration of at least about 55% was used, the Ti
and Al concentrations were less than about 0.005 mass %,
demonstrating that Ti and Al were oxidatively removed at the
melting stage. Since Ti and Al are oxidatively removed at the
melting stage, refining is completed within the time the material
melts and rises to the temperature required for tapping. In
contrast, when an iron oxide source having an iron concentration of
less than about 55% was used, the Ti concentration was about 0.005
mass % or greater.
[0027] With respect to exemplary embodiments of the present
invention, the Fe-based amorphous alloy and its content ranges are
explained below. Unless specifically indicated, all content ranges
are expressed in mass %.
[0028] B can effectively improve amorphous phase forming ability
and thermal stability. It may be added in an amount suitable in
light of the property requirements. When B content is less than
about 2%, amorphous phase cannot be obtained stably, and when it
exceeds about 4%, the melting point rises to make amorphous phase
formation difficult.
[0029] Si can also effectively improve amorphous phase forming
ability and thermal stability. It may be added in an amount
suitable in light of the property requirements. When Si content is
less than about 1%, amorphous phase cannot be obtained stably, and
when it exceeds about 6%, its effect of improving thermal stability
saturates.
[0030] C can effectively enhances the magnetic flux density of
amorphous alloy ribbon and improves amorphous phase forming ability
(improves castability). Its content is decided as a suitable amount
in light of the property requirements. The wettability between the
molten alloy and the cooling substrate can be improved to form a
good amorphous alloy ribbon by making the C content 0.001% or
greater and preferably 0.003% or greater. In addition, C content is
preferably made 0.01% or greater, because an effect of improving
amorphous phase forming ability is obtained. When C content exceeds
3%, the effect of enhancing magnetic flux density declines.
[0031] P can effectively improves core loss property and amorphous
phase forming ability. P may be included in an amount suitable in
light of the property requirements. Although presence of P can
improve core loss property and amorphous phase forming ability, and
may increase the allowable content of impurity elements, the
effects of amorphous phase forming ability improvement and core
loss property improvement may not be observed at a P content of
less than about 0.008%. In addition, the effect of increasing the
allowable content of the impurity elements Mn and S may not be
exhibited. With increasing amount of P addition, cracks more
readily propagate in the amorphous alloy ribbon, thereby degrading
workability. Therefore, to avoid such problem, P content may be
preferably about 0.15% or less.
[0032] Moreover, the effect of the exemplary embodiment of the
present invention is not particularly impaired when for the purpose
of improving magnetic flux density, corrosion resistance property,
annealing conditions and the like, the Fe of the composition of the
exemplary embodiment of the present invention Fe-based amorphous
alloy can be partially replaced by at least one of Co plus Ni of at
most about 20% of the Fe content and Cr of not greater than about
6% of the Fe content. Although Co and Ni can effectively improve
magnetic flux density, they are expensive, so that from the
viewpoint of raw material cost, the replacement of Fe thereby may
be preferably held to about 10% or less and also preferably to
about 5% or less of the Fe content.
[0033] Moreover, the effect of the exemplary embodiment of the
present invention is in no way impaired by including in the
composition of the invention Fe-based amorphous alloy as
constituent elements not only Fe, B, Si, C, P, Ni, Co and Cr and
also known constituents such as N, Ti, Zr, V, Nb, Mo, and Cu.
TABLE-US-00001 TABLE 1 Iron Ti concentration (mass %) Al
concentration (mass %) Iron oxide concentration Mix After Mix After
source used (mass %) concentration melting concentration melting
Sintered ore 58 0.037 0.003 0.022 0.002 Iron ore 65 0.039 0.002
0.023 0.001 Steelmaking 64 0.032 0.002 0.021 0.001 dust FeO reagent
77 0.035 0.001 0.019 <0.001 Steelmaking 53 0.033 0.006 0.022
0.004 dust Mixed 49 0.034 0.008 0.021 0.006 steelmaking dust &
slag Mixed 44 0.036 0.012 0.022 0.008 steelmaking dust &
slag
[0034] Ti and Al can decline to less than about 0.005 mass %
insofar as the temperature is equal to or higher than the matrix
melting point but that the higher the temperature, the better is
the Ti and Al oxidation efficiency, the lower is the final Ti and
Al concentration, and the better are the B and Si yields. However,
the higher the temperature, the greater is the amount of electric
power needed for melting and the greater is the melting furnace
refractory cost. The molten alloy temperature may therefore be
preferably lowered to the level at which the required amount of Ti
and Al oxidative removal can be achieved.
EXAMPLES
[0035] The exemplary embodiments of the present invention can be
explained based on the following examples.
First Set of Examples
[0036] Amorphous alloy raw material produced using a 3-ton class
high-frequency melting furnace were subjected to Ti and Al
oxidative refining. As main raw material was used low-cost magnetic
steel scrap and Fe--B of the compositions shown in Table 2. Certain
amount of Fe--Si was used for Si concentration adjustment. The
amounts of the raw materials per unit mass are also shown in Table
2.
TABLE-US-00002 TABLE 2 (Mass %) Amount per Si B Ti Al unit mass
(kg/t) Magnetic 1.59 0.002 0.002 0.037 825.0 steel scrap Fe--B 0.49
19.89 0.20 0.058 168.4 Fe--Si 74.9 -- -- -- 6.6 Mixing 1.89 3.35
0.035 0.040 1000.0 proportion
[0037] The main raw materials were melted and the molten alloy was
then heated to 1,500.degree. C. In the Invention Examples, as shown
in Table 3, the same iron oxide sources as used in the small-scale
experiment, namely, iron ore (Mount Newman: iron content of 65 mass
%), steelmaking dust (dust occurring during decarburization
treatment: iron content of 64 mass %), and sintered ore (iron
content of 58 mass %), were each added in an amount of 150 kg (50
kg/t) and the melt was tapped 20 min thereafter. In certain
Examples, C, P, Co, Ni and Cr were added to the main raw material
for property improvement. Specifically, the molten composition
after melting was made to contain one or both of C: about 0.001 to
3% and P: about 0.008 to 0.15%, and/or the Fe thereof was partially
replaced by one or more among Co plus Ni of not greater than about
20% of the Fe content and Cr of not greater than about 6% of the Fe
content. A refining operation was also similarly conducted. In the
Comparative Examples, the same or similar method was used except
that the refining treatment was conducted with addition of iron
oxide sources having an iron content of less than 55 mass %, e.g.,
about 150 kg of steelmaking dust (e.g., dust occurring during hot
metal pretreatment: iron content of about 53 mass %) or mixed
steelmaking dust and slag.
[0038] Table 3 shows the compositions of the molten alloys sampled
just before iron oxide source addition and Table 4 shows the
compositions of the molten alloys just before tapping. The
Exemplary Embodiment, which used iron oxide sources having iron
content of 55 mass % or greater, had their concentrations of both
Ti and Al lowered to less than 0.005 mass %, a level at which no
effect on magnetic properties is observed. They were also found to
be low in B and Si oxidative loss and have yields of 95% or greater
relative to the initial mixing proportions. Moreover, in cases
where the composition contained one or both of C: 0.001 to 3% and
P: 0.008 to 0.15%, and the case where the Fe thereof was partially
replaced by at least one of Co plus Ni of at most 20% of the Fe
content and Cr of not greater than 6% of the Fe content, these
effects were not impaired. In contrast, in the Comparative
Embodiment, which used iron oxide sources having iron content of
less than 55 mass %, the B and Si yields were on the same level but
Ti concentration or Al concentration was 0.005 mass % or
greater.
TABLE-US-00003 TABLE 3 Iron Iron oxide source concentration
Composition before iron oxide source addition (Mass %) Example used
(mass %) Si B Ti Al C P Co Ni Cr Exemplary Embodiment 1 Iron ore 65
1.87 3.31 0.034 0.039 -- -- -- -- -- Exemplary Embodiment 2
Steelmaking dust 64 1.89 3.31 0.035 0.038 -- -- -- -- -- Exemplary
Embodiment 3 Sintered ore 58 1.88 3.32 0.034 0.039 -- -- -- -- --
Exemplary Embodiment 4 Iron ore 65 1.89 3.34 0.034 0.040 2.92 0.007
0.0005 0.002 0.002 Exemplary Embodiment 5 Iron ore 65 1.88 3.31
0.035 0.040 0.0009 0.142 0.0006 0.001 0.001 Exemplary Embodiment 6
Iron ore 65 1.89 3.33 0.034 0.039 0.0011 0.010 0.0005 0.001 0.001
Exemplary Embodiment 7 Iron ore 65 1.89 3.33 0.036 0.040 0.0008
0.007 17.4 0.001 0.001 Exemplary Embodiment 8 Iron ore 65 1.87 3.30
0.034 0.039 0.0009 0.007 0.0005 16.9 0.001 Exemplary Embodiment 9
Iron ore 65 1.89 3.33 0.036 0.038 0.0009 0.006 0.0005 0.001 4.93
Exemplary Embodiment 10 Iron ore 65 1.90 3.36 0.032 0.039 0.0008
0.006 2.11 1.97 0.001 Exemplary Embodiment 11 Iron ore 65 1.88 3.33
0.034 0.039 0.0009 0.007 4.84 0.001 4.56 Exemplary Embodiment 12
Iron ore 65 1.89 3.33 0.034 0.039 0.0007 0.007 0.0005 4.95 3.81
Exemplary Embodiment 13 Iron ore 65 1.89 3.34 0.034 0.038 0.0007
0.006 1.68 1.77 2.68 Comparative Embodiment 1 Steelmaking dust 53
1.87 3.31 0.033 0.037 -- -- -- -- -- Comparative Embodiment 2 Mixed
steelmaking 49 1.86 3.33 0.036 0.036 -- -- -- -- -- dust & slag
Comparative Embodiment 3 Mixed steelmaking 44 1.88 3.30 0.032 0.039
-- -- -- -- -- dust & slag
TABLE-US-00004 TABLE 4 Composition before tapping (Mass %) Yield
(%) Example Si B Ti Al C P Co Ni Cr Si B Exemplary Embodiment 1
1.80 3.19 0.003 0.002 -- -- -- -- -- 95.3 95.2 Exemplary Embodiment
2 1.81 3.21 0.003 0.002 -- -- -- -- -- 95.8 95.8 Exemplary
Embodiment 3 1.81 3.20 0.004 0.003 -- -- -- -- -- 95.8 95.5
Exemplary Embodiment 4 1.80 3.19 0.003 0.002 2.91 0.007 0.0005
0.002 0.002 95.3 95.2 Exemplary Embodiment 5 1.81 3.21 0.003 0.002
0.0009 0.141 0.0006 0.001 0.001 95.8 95.8 Exemplary Embodiment 6
1.80 3.19 0.003 0.002 0.0011 0.010 0.0005 0.001 0.001 95.3 95.2
Exemplary Embodiment 7 1.80 3.20 0.002 0.001 0.0008 0.010 17.4
0.001 0.001 95.3 95.5 Exemplary Embodiment 8 1.81 3.20 0.003 0.002
0.0009 0.010 0.0005 16.9 0.001 95.8 95.5 Exemplary Embodiment 9
1.81 3.19 0.004 0.002 0.0009 0.010 0.0005 0.001 4.92 95.8 95.2
Exemplary Embodiment 10 1.80 3.21 0.003 0.002 0.0008 0.010 2.11
1.97 0.001 95.3 95.8 Exemplary Embodiment 11 1.81 3.20 0.002 0.001
0.0009 0.010 4.83 0.001 4.56 95.8 95.5 Exemplary Embodiment 12 1.80
3.19 0.003 0.002 0.0007 0.010 0.0005 4.94 3.81 95.3 95.2 Exemplary
Embodiment 13 1.80 3.19 0.003 0.002 0.0007 0.010 1.68 1.77 2.67
95.3 95.2 Comparative Embodiment 1 1.80 3.20 0.006 0.004 -- -- --
-- -- 95.3 95.5 Comparative Embodiment 2 1.79 3.21 0.008 0.005 --
-- -- -- -- 94.8 95.8 Comparative Embodiment 3 1.82 3.18 0.010
0.006 -- -- -- -- -- 96.4 94.9
Second Set of Examples
[0039] Raw material of the same kind in the same amount as used in
Example 1 was charged into a 3-ton class high-frequency melting
furnace together with an iron oxide source that, as shown in FIG.
2, had an iron content of more than 55 mass % before melting,
whereafter melting was conducted. When approximately 10 min had
passed following raw material meltdown, the temperature was
measured and the molten alloy was sampled. After the temperature
had risen to 1,500.degree. C., the molten alloy was sampled and
then tapped. In some Exemplary Embodiments, C, P, Co, Ni and Cr
were added to the main raw material for property improvement.
Specifically, the amorphous alloy composition after melting was
made to contain one or both of C: 0.001 to 3% and P: 0.008 to
0.15%, and/or the Fe thereof was partially replaced by one or more
among Co plus Ni of not greater than 20% of the Fe content and Cr
of not greater than 6% of the Fe content. A refining operation was
also similarly conducted. In the Comparative Embodiments, the same
method was used except that, as shown in Table 4, melting was
conducted using iron oxide sources having an iron content of less
than 55 mass %.
[0040] Table 5 shows the compositions of the molten alloys after
meltdown and Table 6 shows their compositions just before tapping.
The Exemplary Embodiments, which used iron oxide sources having
iron content of 55 mass % or greater, had their concentrations of
both Ti and Al lowered to less than 0.005 mass %, a level at which
no effect on magnetic properties is observed, from the stage in
which the material melted down, and the Ti and Al concentrations
decreased still further at the tapping stage after temperature
increase. They were also found to be low in B and Si oxidative loss
and have yields of 92% or greater relative to the mixing
proportions before tapping. Moreover, in case where the composition
contained one or both of C: 0.001 to 3% and P: 0.008 to 0.15%, and
the case where the Fe thereof was partially replaced by one or more
among Co plus Ni of not greater than 20% of the Fe content and Cr
of not greater than 6% of the Fe content, these effects were not
impaired. In contrast, in the Comparative Embodiments, which used
iron oxide sources having iron content of less than 55 mass %, the
B and Si yields were on the same level but Ti concentration or Al
concentration was 0.005 mass % or greater.
TABLE-US-00005 TABLE 5 Iron concentration Composition after
meltdown (Mass %) Example Iron oxide source used (mass %) Si B Ti
Al C P Co Ni Cr Exemplary Iron ore 65 1.87 3.31 0.003 0.002 -- --
-- -- -- Embodiment 1 Exemplary Steelmaking dust 64 1.89 3.31 0.003
0.002 -- -- -- -- -- Embodiment 2 Exemplary Sintered ore 58 1.88
3.32 0.004 0.003 -- -- -- -- -- Embodiment 3 Exemplary Iron ore 65
1.89 3.34 0.003 0.002 1.99 0.007 0.0005 0.002 0.002 Embodiment 4
Exemplary Iron ore 65 1.88 3.31 0.003 0.001 0.0009 0.144 0.0006
0.001 0.001 Embodiment 5 Exemplary Iron ore 65 1.89 3.33 0.004
0.002 0.0012 0.010 0.0005 0.001 0.001 Embodiment 6 Exemplary Iron
ore 65 1.89 3.33 0.002 0.002 0.0008 0.007 15.8 0.001 0.001
Embodiment 7 Exemplary Iron ore 65 1.87 3.30 0.003 0.002 0.0009
0.006 0.0005 16.2 0.001 Embodiment 8 Exemplary Iron ore 65 1.89
3.33 0.002 0.001 0.0008 0.007 0.0005 0.001 4.88 Embodiment 9
Exemplary Iron ore 65 1.90 3.36 0.003 0.002 0.0008 0.006 2.38 1.56
0.001 Embodiment 10 Exemplary Iron ore 65 1.88 3.33 0.004 0.002
0.0009 0.007 4.64 0.001 3.24 Embodiment 11 Exemplary Iron ore 65
1.89 3.33 0.003 0.002 0.0008 0.007 0.0005 4.95 4.22 Embodiment 12
Exemplary Iron ore 65 1.89 3.34 0.003 0.002 0.0007 0.007 1.22 1.58
2.34 Embodiment 13 Comparative Steelmaking dust 53 1.87 3.31 0.033
0.037 -- -- -- -- -- Embodiment 1 Comparative Mixed steelmaking
dust 49 1.86 3.33 0.008 0.006 -- -- -- -- -- Embodiment 2 &
slag Comparative Mixed steelmaking dust 44 1.88 3.30 0.011 0.008 --
-- -- -- -- Embodiment 3 & slag
TABLE-US-00006 TABLE 6 Meltdown temp Composition before tapping
(Mass %) Yield (%) Example (.degree. C.) Si B Ti Al C P Co Ni Cr Si
B Exemplary 1376 1.75 3.10 0.002 0.001 -- -- -- -- -- 92.7 92.5
Embodiment 1 Exemplary 1370 1.74 3.11 0.002 0.001 -- -- -- -- --
92.1 92.8 Embodiment 2 Exemplary 1380 1.76 3.09 0.003 0.002 -- --
-- -- -- 93.2 92.2 Embodiment 3 Exemplary 1380 1.75 3.09 0.003
0.002 1.98 0.007 0.0005 0.002 0.002 92.7 92.2 Embodiment 4
Exemplary 1375 1.75 3.10 0.002 0.001 0.0009 0.144 0.0006 0.001
0.001 92.7 92.5 Embodiment 5 Exemplary 1372 1.76 3.10 0.003 0.002
0.0012 0.010 0.0005 0.001 0.001 93.2 92.5 Embodiment 6 Exemplary
1380 1.77 3.10 0.002 0.001 0.0008 0.007 15.8 0.001 0.001 93.7 92.5
Embodiment 7 Exemplary 1382 1.75 3.09 0.003 0.002 0.0009 0.005
0.0005 16.2 0.001 92.7 92.2 Embodiment 8 Exemplary 1380 1.76 3.11
0.002 0.001 0.0008 0.006 0.0005 0.001 4.86 93.2 92.8 Embodiment 9
Exemplary 1371 1.75 3.09 0.003 0.002 0.0008 0.006 2.38 1.56 0.001
92.7 92.2 Embodiment 10 Exemplary 1379 1.75 3.10 0.003 0.001 0.0009
0.007 4.64 0.001 3.24 92.7 92.5 Embodiment 11 Exemplary 1371 1.76
3.09 0.002 0.001 0.0008 0.007 0.0005 4.95 4.21 93.2 92.2 Embodiment
12 Exemplary 1375 1.76 3.09 0.003 0.002 0.0007 0.007 1.22 1.58 2.33
93.2 92.2 Embodiment 13 Comparative 1375 1.75 3.11 0.006 0.004 --
-- -- -- -- 92.7 92.8 Embodiment 1 Comparative 1374 1.75 3.09 0.008
0.005 -- -- -- -- -- 92.7 92.2 Embodiment 2 Comparative 1376 1.74
3.09 0.010 0.006 -- -- -- -- -- 92.1 92.2 Embodiment 3
INDUSTRIAL APPLICABILITY
[0041] The exemplary embodiments of the present invention provides
a process for production of an amorphous alloy at low cost by
efficiently removing magnetic-property-degrading Al and Ti when
using inexpensive Fe--B or scrap as an amorphous alloy raw
material.
[0042] The foregoing merely illustrates the exemplary principles of
the present invention. Various modifications and alterations to the
described embodiments will be apparent to those skilled in the art
in view of the teachings herein. It will thus be appreciated that
those skilled in the art will be able to devise numerous
modification to the exemplary embodiments of the present invention
which, although not explicitly shown or described herein, embody
the principles of the invention and are thus within the spirit and
scope of the invention. All publications, applications and patents
cited above are incorporated herein by reference in their
entireties.
* * * * *